Harmonic Damper / Balancer Q&A (combined)

I am having a tough time trying to install this bloody balancer. From what I have read everone just uses a peice of wood and a hammer to install it.

I have tried this and it when on so far then stopped. I then managed to find a strong thin washer and used the bolt to pull it on further. That has stopped now as well. looking from the back there looks to be another 1/2" of travel left.

I am afraid to really reef on the bolt as I don't want to break the bloody thing off then I am really screwed.

Any suggestions?? One buddy suggested that I toss the balanacer in the oven and heating it to 150F to expand it and make it go on easier. Is this a dumb idea?

Please help.

Not realy a good idea to wack at it with a hammer. You can damage things that way. Although we have all done it. (c'mon you know you have) Its's better to use the harmonic balancer installation tool, and it makes life alot easier. Summit carries one from Proform for around 23 or 24 dollars. Part number is PRO-66515.

Here's some info I have collected.-
Installing a balancer (from Chevy Only forum)
Buy, rent or borrow the correct tool. ($20 to $30) No hammers! Autozone will loan you a puller.
Go to Radio Shack and get a spraycan of the freezing cooler for electronics. Put cam break-in compound on the shaft, inside the balancer and on the balancer where the seal rides so the seal is lubed on startup till the oil gets there. Put the balancer in the oven at 200F or boiling water (212f) for a while until it is fully hot and then use the can of freeze mist on the crank nose, cooling it as best possible (you don't want to spray the whole can at once) and then quickly get the balancer out of the oven and slip it on the crank nose. The balancer will slide on until it hits the limit point. Don't get it too hot or it will damage the elastomer part of the balancer. If you over-tighten the tool it will break off in your crankshaft- bad news.
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Paint a line on the new balancer & pulley so it will be easy to tell if it ever separates & slips.
http://www.rustpuppy.org/ttchapter6/t&t82-2.jpg
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You can easily build your own harmonic balancer installer. Get yourself a leaf spring centerbolt of a sufficient length and a nut. You can use the thick washer that goes on the bolt for the balancer. Place the balancer on the crank by hand and then thread the centerbolt containing the washer and nut into the crank until it bottoms. Tighten the nut to install the balancer. You may want to put a little lube such as grease on the bolt to prevent gaulling the threads of the centerbolt.
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Buy a moroso installation tool, they don't break.. When installing it apply moly lube to the installer threads, the crank nose (including the keyway), and the inside of the balancer.

Ok thanks that is great info. I will give it a try tomorrow and let you know how it goes.

If you mess up your crank bearing thrust surfaces or pull out the threads on the crank snout, or seperate the interia ring from the hub you will wish you did purchase the installer tool. Been there,done that. Yeah it's a tool not used a lot but worth it.
Also maybe hot the inside hole of the damper with a scotchbrite and don't forget to lube the seal.
Jim

Thanks for posting this question. I will be doing the same install when my best buddy(UPS Delivery Guy) shows up with my speed shop order. Can't believe the price of these over size hockey pucks.

I am having a tough time trying to install this bloody balancer. From what I have read everone just uses a peice of wood and a hammer to install it.

I have tried this and it when on so far then stopped. I then managed to find a strong thin washer and used the bolt to pull it on further. That has stopped now as well. looking from the back there looks to be another 1/2" of travel left.

I am afraid to really reef on the bolt as I don't want to break the bloody thing off then I am really screwed.

Any suggestions?? One buddy suggested that I toss the balanacer in the oven and heating it to 150F to expand it and make it go on easier. Is this a dumb idea?

Please help.
I don't know what internet typewriting monkeys told you to hit a damper with a hammer, but that advice is wrong.

You are in the right place for good advice, but put your matched set of BFH's away.


First rule of mechanics: If something is hard to do then something is wrong!
Never wack a balancer with a hammer! Use the proper installation tool.
Pounding on a crank ruins the thrust bearing.
Never heat a balancer. You'll cook the rubber and hasten early failure.
Use the proper puller and remove the balancer. Clean the crank snout and ID of the balancer with a Scothbrite pad. Use an appropriate press fit lube.
You may have already ruined the balancer. The outer ring is held in place only by the elastomer. When each piston fires the crank accelerates and decelerates twisting the crank. The balancer/damper is tuned to absorb these vibrations. This energy is turned into heat. The heat (and ozone in the air) ultimately deteriorates the rubber. Pounding on any balancer strains the rubber (even if you only hit the center, inertia causes the outer ring to jolt.)

A high mileage damper is more prone to failure especially if hit with a hammer.

If it's damaged it will eventually fail and lead to engine damage. It's a good idea to replace a used damper at rebuilding time even if it "looks ok". They have a finite life and if it has anywhere near 100,000 miles on it, it has very few miles left if any.

I posted a link on balancer installation in Mrtimstik's distributor won't time because the balancer is wacked thread (http://stevesnovasite.com/forums/showthread.php?t=25691&page=3&pp=15).

Here it is again: CHP balancer tech tips (http://chevyhiperformance.com/howto/53578/)

Guys,

I don't know what temp the balancer will tolerate before being damaged. I know I clean a lot of them in my spray jet washer and it runs about 190F.
I have considered buying an induction type bearing heater to try.

I balance a lot of engines as well as build them, so I am always installing and removing balancers. I finally built a hydraulic installer and puller. It only takes about 90 seconds to install a balancer now. If you think its hard when the crank is in the motor, try putting it on with crank out!

One thing I should mention is I always measure the crank snout and the balancer bore to make sure you have the proper fit, especially with new (or different) parts. I keep a small dial bore gage set up just for this.
For an example- crank snout on "high limit" and the balancer on "low limit" and it might not only be a bear to install, but you may actually break the balancer in the keway! I have seen this a bunch, and if you don't catch it before firing the motor it could just as well damage the crank.

Im not sure if heating the balancer before installation help prevent cracking, but it may. I talk with balancer manufactures on occasion I will try to remember to ask various ones about mav temps. I know I would love to use an induction heater and an infrared pyrometer if it would work!


Good luck

Jeff

Good points Jeff! I was afraid he was going to heat it to 350-400F! I think the elastomer would melt into goo at that temp.

Hey if you live by an autozone they will rent you the tool and give you all your money back when you return the tool, so 0 cost, and you wont screw up your motor.

Hi,

Im sure that temp would ruin them as well Paul. I saw about 5 that were melted at about 400 degrees when a friends helper tried to clean them in thermal oven. Atleast all the peices were clean!

Damn it anyway. I managed to get a tool. I was just about there and then the bloody tool (bolt) broke in the nose of the crank. Lucky for me there was enough hanging out that I was able to get a plyier on it and unscrew it out from the nose. I think that the nose or balancer or key is to big. Something is just not right. I am gonna take the balancer back and see if another one gives me the same problems.

i have a strange question, not to steel the thread but since its on the topic.,
maybe paul or stock z/28 can answer.

years ago i built a 327 out of a 350 block and a 307 crank. the crank didnt have a threaded hole in the end. it didnt take a center bolt. ive never seen one this way, but i had plenty of problems , so many loose balancer probs i drilled and tapped a hole in it and finally it was fixed,

have either of you come across this?? no hole for a center balancer bolt?

i ask cause i bfh it back on so many times. never ruined anything, but it sucked.

Hi,

Yes most of the early low performance cranks were not drilled and taped. I dont do as many anymore but I used to drill and tap a lot of 327 and 283 cranks. The early standard type motors just relied on "press fit". You did the right thing to drill and tap it.

Jeff

Brad I would definatly check the sizes on your parts.

Jeff

I am about to purchase a damper and one of the notes states," Dampers are honed for stock cranks--steel hubs may need to be honed for aftermarket cranks....." My crank hub measures 1.247" diameter. I will check the ID of the damper before I install to see how much press there really is. A thousandth of an inch of interferance can be a buster without the right install tool. I would imagine lube helps also.

Well I did some measuring, which is what I should have done on the first go around. The balancer had measurements in the instructions to check to make sure all is well. I was within tolerances on everything. So what could it be?? Then I took the timing cover off so I could get at the key. I replaced the key just to be sure that it was not an issue. It didn't look right. After I put it all back together I had a look and though "I wonder if it was already all the way on?" I measured the depth of the snout and then compared it to the balancer. Well guess what, when the balancer is fully on there is 1/4" space between the balancer and the block. DOH!!!!! I broke the tool because the unit was installed as far as it could go.

I got a buddy to machine me the replacement part for the tool and installed the balancer with no issues.

Thanks to all that had good info. Btw in the instructions from the mfg says to use a hammer and wood if you don't have a tool. Go figure eh.

Thanks to all that had good info. Btw in the instructions from the mfg says to use a hammer and wood if you don't have a tool. Go figure eh.

now that is too funny....but it does sorta make sense the would say that as they are, after all, in the business of selling new ones...so the sooner it comes apart on you the better off they are so to speak :rolleyes: :)

Hi guys,



That's cool its fixed. Im glad it was something simple. Sometimes its hard to tell if the balancer is all the way on. I have a gage that I made that measures from the front of the block to the face of the balancer, this helps when trying to figure out pulley misalignment.

One thing I probably should have mentioned earlier is that I always put a small amount silicone sealer in the balancer key way before installing it. I have seen some engines that would leak oil out the front of the balancer. I think most of the engines come sealed this way from the factory as well.

The best installation lube I have found is molly assembly lube. I us ARP but it may all be the same.


Good Luck
Jeff

Well I did some measuring, which is what I should have done on the first go around. The balancer had measurements in the instructions to check to make sure all is well. I was within tolerances on everything. So what could it be?? Then I took the timing cover off so I could get at the key. I replaced the key just to be sure that it was not an issue. It didn't look right. After I put it all back together I had a look and though "I wonder if it was already all the way on?" I measured the depth of the snout and then compared it to the balancer. Well guess what, when the balancer is fully on there is 1/4" space between the balancer and the block. DOH!!!!! I broke the tool because the unit was installed as far as it could go.

I got a buddy to machine me the replacement part for the tool and installed the balancer with no issues.

Thanks to all that had good info. Btw in the instructions from the mfg says to use a hammer and wood if you don't have a tool. Go figure eh.
You know....I meant to ask you how far away the balancer was from the block. They do not sit flush or even close to flush when they are installed properly. Sucks you went through all the trouble for nothing. Oh well...just chalk it off as a learning experience.

Dave

Definately check the parts. A couple of thousandths go along way to making it impossible to install.

For whats it's worth,I've put the keyways in the freezer to get them to contract and then install them.They will fit right right in with a slight tap of a plastic or soft hammer and them let them warm up to room tempature.
It really works!
Mike

My install went perfectly. Had the tool from Summit. I did have to take it off the first time I tried and sandpaper off a little bit of coining I kicked up in the ID of the damper and on the crank snout. No big deal tho. Second time it went on smooth as can be cause I did tap it a little bit with a soft face mallet while engaging the fit. The car runs the same as ever tho. I gotta start puttin my money in, "go fast" parts, not just parts.

One thing I probably should have mentioned earlier is that I always put a small amount silicone sealer in the balancer key way before installing it. I have seen some engines that would leak oil out the front of the balancer. I think most of the engines come sealed this way from the factory as well.


I been fighting an annoying slow oil leak on the front of the motor since day one... I wonder if this could be it. I know this drawing probably has all sorts of errors, but is this what could be happening?

http://www.stlnovas.org/images/harmonic_balancer_leakage.JPG

okay here is the scoop I was installing the harmonic balancer and the wonder full snap on tool that I had for installing broke so I have tried drilling the hole and using an extractor bit does not work... what can you do I don't want to heat it because it is a freshly rebuilt engine I would try welding it but it might bugger the threads

If you have a Tig welder, you can weld a tit on the broken bolt, then weld a nut onto the nut. Tap on the nut a few times and from the heat of welding the tit on and tapping on it, it should come right out. That's how I get my broken exhaust manifold bolts out of the head. Good luck!!

TJ

That's real odd, since Snap-on makes good stuff. Was it real hard to get on?
Remember the first rule of mechanics, if it's hard to do then something is wrong.
If you were turning the inner bolt when you should be turning the outer nut, that would explain what happened. If not, I seem to remember a similar thread about a hard to install damper. You might want to look for it and review what was said.
I wouldn't use heat and the welding idea is risky. You may need to take it apart, but 1st try a cobalt LH drill bit. You'll also need a reversable, variable speed drill and a center punch so it doesn't walk. Drill slowly.. once it grabs the stub should walk out.
It's going to be winter for a long time up there so you have time to do it right.

I have tried drilling the hole and using an extractor bit does not work Did you ever get a proper hole drilled or have a prob w/the extractor?

Is the engine installed? (access for work)

Did you ring off the bolt due to tight thread engagement or over powered pulling in a tight fitting balancer? The dif is...IF you have that bolt in there due to threads seizing, then you WON'T get it out w/an extractor (and probably snap THAT puppy off and in REAL deep doo doo).

I'd drill or P-grind with a carbide burr what ever is left out to the tap drill size and re-thread / chase the old tapped hole. I do this kinda' stuff for a living (when I HAVE to). Wish you were closer.

Did the bolt snap off flush with the crank snout?

maxturbo hit the most important points here....please do not even try with an extractor or reverse bit of any kind if its siezed, you will only make it a buttload more difficult or even impossible without some serious work....

I'd drill or P-grind with a carbide burr what ever is left out to the tap drill size and re-thread / chase the old tapped hole


that is what needs to be done here....start small with the bits DO NOT BREAK THEM IN THERE...and work up, sometimes if you get big enough you can pick around the threads to get the remnince(sp?) out....or if needed you could helicoil it

if its just in there and not siezed, i would try and walk it out with a punch and a hammer before applying any kind of heat or drilling

Wholman, the same thing happened to me. I was inexperienced, bottomed out the pilot bolt in the crank, and while tightening the nut, snapped the bolt. The bolt was irregular, with a small point outside the crank and some broke off inside a couple of threads deep. I talked to the guy who did my machine work and he told me that the shattered bolt had probably messed up the outermost threads in the crank. He then said to:
1. Break off anything sticking out.
2. Use a large drill bit (9/16") and drill centered on the crank to get a uniform surface to work from. Go a couple of threads deep into the crank.
3. With a reverse drill bit (smaller than the bolt) drill into the bolt. That should walk the bolt out of the crank.
It worked like a champ for me.
Hope this helps.

JoeII

This might be what Paul is referring to.

http://www.aldn.com/drillout/

These things have never failed for me.
The maintanence crew uses them where I work and they never failed to remove a broken bolt. Does not seem to matter if the bolt is rusted or corroded. Siezed (gaulded) threads may be another issue. Maybe not.
If you use them, make sure you follow directions and put some oil on the threads of the broken bolt.
Don

No, but that might work. The drilling tips they list are valid and relevant.
The part should back out if it isn't seized in the threads.

Hi,

Yes that's what I was referring to, and the drawing looks pretty good to me.

Jeff

I have been browsing past topics involving harmonic balancers and looking at my Chilton's manual. I have never done anything like this and know little about engines. My manual has very little information about changing the balancer. What is the general process that I should use to change the balancer? Are there any little trick or things not to do that I need to know about? The information is for a I6 230 engine.

Thanks in advance,
John W.

Greetings,

Definitely use a puller and go very, very slow as a broken bolt really makes everything a big pain! Otherwise, it's rather simple.

Jason

You should get a pulley INSTALLATION tool as well so as not to have to beat the balancer back on. Clean / sand / file any burrs off the O.D. and I.D. of the parts before re-assembly, and grease those slide-on portions too. You should be able to get a free loan on the tools at places like Advanced Auto or Autozone. Don't lose that woodruff key when you pop off the balancer! ;)

Is the balancer BAD or are you going in for cam, timing chain and / or front seal replacement?

You MAY have to remove your radiator too for adequate tool & wrench clearance.

These should help too...
http://www.diynetwork.com/diy/en_engine_block/article/0,2021,DIY_13807_2276768,00.html
http://www.mytoolstore.com/wilmar/wtech06.html
http://chevyhiperformance.com/howto/53578/

The balancer is bad. The rubber gave way while I was driving the car.

Thanks for the information,
John W.

Does your motor have a balancer bolt or is it pressed on?

Does your motor have a balancer bolt or is it pressed on?

I believe ALL balancers have an interference fit (pressed type fit) on the crank snout BUT not all cranks have threaded snouts to accept a balancer bolt. Kapish ;)

I believe ALL balancers have an interference fit (pressed type fit) on the crank snout BUT not all cranks have threaded snouts to accept a balancer bolt. Kapish ;)

Yeah, I know that! My question was going to be directed towards the installation of the new balancer. It's much easier with a threaded crank snout and using a balancer installation tool.

Yeah, I know that! My question was going to be directed towards the installation of the new balancer. It's much easier with a threaded crank snout and using a balancer installation tool.


for sure...lol...without the bolt just use a hammer...Kapish:eek: :rolleyes: :)

Just joking.:) ..Hammer + Balancer = potential balancer failure

If it were me I would drill and tap the balancer snout for a bolt.

I followed the installation instructions that came with my Summit SFI dampener. I heated the dampener in the oven per the instructions, coated the crank snout with fresh oil, quickly removed the dampener from the oven and placed it on the crank snout. The installation tool pulled that sucker on super easy :)

The balancer is just pressed on. There is no threaded hole for a bolt.

Thanks,
John W.

The balancer is just pressed on. There is no threaded hole for a bolt. Then that kills the idea of using an INSTALLATION tool (it threads into the crank center). Looks like it's the old hammer and 2 x 4 for you my friend! Don't worry, MANY a balancer has been driven home this way. Just make sure that you clean up the mating slide-on sufaces and get that key stock positioned correctly, and smack the balancer dead center watching to not get it cocked. ;)

Damper installation and problems thread (http://stevesnovasite.com/forums/showthread.php?t=25935)

What about fluid type dampners? Can they take additional heat for installation?

The rubber gave way while I was driving the car.

That's what happened to me and now my wife is pregnant again :eek: ;) :D

good one WFO! :D :)

Anyone got an idea what one of these in good condition is worth?
That is the correct balancer for a '66 L79 isn't it?
Thanks!

I have an early 327 with a pressed on harmonic balancer or in other words the crank is not tapped for a bolt. I have removed the balancer with a puller and am ready to put it back on. I have read the posts about not hammering it and getting the installation tool but with no threads in the crank, how will this installation tool help? So how do I put the balancer back on without hammering it on? Thanks, 63-ChevyII, Mike

I thought this was covered in best of tech Harmonic Balancer problems (http://stevesnovasite.com/forums/showthread.php?t=25935).

Basically you need to make sure the shaft and hub are burr and rust free and use plenty of press fit lube. Heating the hub will help and use an aluminum block to protect the hub. Don't strike the outer ring.

Thanks for the reply, I did read that thread before posting, it seems to point back to, heat or no heat and drilling and threading the crank and using an installing tool. I plan to try to tap it back on. I guess my real question was, Chevy made a lot of these cranks in the late 50's and early 60's that were made to be press fit, this has to simple, how did they replace the balancer "Back In The Day"? 63-Chevy-II, Mike

If you heat the dampener in the oven, it will expand and go on a lot easier. You have to be quick to install it after you pull it from the oven. Like Paul suggested, make sure the snout is deburred, apply some oil to the snout and inside of the dampener. Use a block of wood, aluminum, etc between the dampener and the hammer while you tap it into place. This protects the dampener and also distributes the force from the hammer.

Heat in the oven to 300 degrees. Or, go to a welding supply and get a, I think they're "heat sticks", like a crayon that melts at a specific temp. They come in different temps, mark the dampner, heat it from the inside with a torch and QUICKLY smack it on, have a LARGE hammer ready, two man operation. Have never had a seal problem, if that was your next question.

I would be concerned with going too high in temperature(300 degrees). The concern would be for the material between the inner and outer ring. I'd be more comfortable going 200 degrees.

I had a 327 with same problem and ended up drilling and tapping it out, After it came off going down the road.

My 6 cyl is press on, and I just used a brass hammer to tap it on. Worked great, took my time and did not touch the outer ring.

I don't care what it takes. Drill and tap a hole in your crank. This just isn't for ease of installation, it is for safety. There is a reason that all of balancers are now bolted on. Plus if you are ever go to the track and they notice that it isn't bolted, they won't let you run.

Thanks for the input guys. To Hammer or Drill & Tap??? After a very tight pull to get the lower timing gear off I decided to take the time to drill and tap the crank and use the installation tool. I have hammered the lower timing gear on as well as the harmonic years ago, I really didn't think much about it, just kept banging away. The installer is a sweet tool and definitely the way to go, of course you have to have a tapped crank to use the tool. Couldn't beat the tool rental price, Advance Auto borrows the "Puller and Installer kit" out for free, with deposit of course, at least my local one does. I bought 7 quarts of oil so I wouldn't feel too guilty about just walking out with the tool. FYI it is a 7/16 20 thread, drilled 1 1/2" deep. Best off getting a bolt and washer off of an old block or from the bone yard. "W" is the correct size drill which is .380 I couldn't find a "W" drill bit and used a 3/8" or .375, the .005 didn't seem to make any difference and worked fine. This installation tool is designed to push on the harmonic balancer not the lower timing chain gear but I picked up a 2" long 1 1/4" pipe nipple at the hardware store and it worked perfectly with the tool to push the lower gear on, 63-ChevyII..Mike..X-Hammer-Mechanic ????

Just wondering about the size differences of balancers, I have an 8" and need a new one because it won't seal on the timing cover seal. I have tried a speedy sleeve and it still leaks. The balancer I have is 1" 5/8 wide and the one I ordered from NAPA is only 1" 1/4 wide, can I use this one or should I get one that is the same width as the one I have? Thanks

regardless of the replacement units size... i got caught with one that the keyway and timing mark weren't oriented the same... so if the advice you get says use the slightly thinner unit (i think you'll be ok) lay 'em on top of each other with the keyways lined up and confirm the line's in the right spot...


took me a little while of wondering why my timing was off... when it wasn't...


i hope i helped and wish ya well :)

The balancer ring can be thinner as long as the overall height is the same. If the overall height is shorter your pulleys will no longer line up. So place them on the counter and compare the height.
As John said compare the keyway/timing mark alignment also. If your balancer is very old the outer ring may have shifted a little so just make sure the keyway/timing mark alignment is close, if not right on.

I have found most balancers and pointers are not right. When you get whatever balancer you decide to use I'd find TDC and be sure the timing pointer is correct. We check every motor we build now and most require some correction. We use to drill, tap and counter sink the outer ring to the inside case with 3 screws evenly spaced to keep the outer ring from shifting or coming off. Everyone seems to use aftermarket balancers now. Many racing classes mandate an aftermarket balancer today. Just a suggestion. RM

Hi,

Like everyone said make sure the timming orientation is correct, and I was wondering what type of motor are you working on? Most of the thick balancers were OE only on the pretty trick motors L79-302-LT1s etc. Be shame to lose some originality.

Some times the balancer will leak internaly between the crank keys. I always put some silicon in the keway to seal this, before installing the balancer.

Jeff

Is there a way to repair the center bolt threads on the crankshaft or get a new crank? The motor runs fine but need to replace the timing chain. Someone before me stripped the center bolt hole. Thanks

Try a Heli-coil repair but use a drill bushing to help you drill straight.

The hole is deep and not threaded all the way in. When I stripped one, I tapped it all the way down and used a longer bolt with loctite.

I had to use an insert before, no problem. Nutsert, Helicoil, or my current fave-Recoil.

i have a strange question, not to steel the thread but since its on the topic.,
maybe paul or stock z/28 can answer.

years ago i built a 327 out of a 350 block and a 307 crank. the crank didnt have a threaded hole in the end. it didnt take a center bolt. ive never seen one this way, but i had plenty of problems , so many loose balancer probs i drilled and tapped a hole in it and finally it was fixed,

have either of you come across this?? no hole for a center balancer bolt?

i ask cause i bfh it back on so many times. never ruined anything, but it sucked.
To add a little to Jeff's answer, the inertia ring was a lot smaller on the early units and they didn't seem to take a lot of beating to get them on. 6 cyl engines were the same way, no threaded hole. When possible I would have someone hold forward on the rear of the crank to keep the thrust bearing from taking a beating.

I am trying to remove the wobbly harmonic balancer off my car so I can replace it. I sprayed some penetrating oil on the bolt before I tried to remove it, and have been spraying oil on it as I tried to get it off. I had to "wedge" the flywheel just to get the bolt to break loose. I got it to start loosening with a large breaker bar, and it loosened about a turn and started getting tight again. So I called the local speed shop to make sure I was loosening it the right direction (left) and he said I was. So I tightened it back down and tried to loosen it again. It went about 2 turns (hard) and I sprayed it some more and tried to tighten it again to "work" it. It doesn't want to tighten back up now, and I am afraid of breaking it off or something :eek: I have like 1/8" play now between the washer and the balancer. I am debating whether to pull the radiator out so I can get to it with an impact......
I am going to work shortly - so I'll check out your replies probably tomorrow am.
Help please!!!!!

Stop! Don't put an impact on it or use a cheater pipe on it until we hear from one of our machinist gurus.
I'm afraid that the damage is already done! Lets try to save your crank's threads. Bolts are cheap-crankshafts aren't!
Sounds like either one or the other is having the threads twisted out and is trying to cross-thread.
If you cross-thread it to much or break off the bolt,you'll have to take your crank out!
My two cents worth Mike

sounds like it was cross threaded on in the first place! I've personally never had a bolt cross thread on the way out. At this point I don't really see you having a choice but to remove the bolt and deal with what is damaged. If the threads are damaged I wouldn't want to leave it on there! If the threads are damaged you will probably have to remove the crank to fix it, since I don't think you can use a heli coil in that area. Even if you can use a heli coil I don't know of very many machine shops with the tooling to drill and tap that in place since you are dealing with a balanced component. You might be able to get away with doing it in place on a basic street engine, but I would not want to try it on a performance engine that sees high RPM's.

I recently bought a dead Foord F-100 and pulled the dead 302. The harmonic balancer bolt removal acted most odd (engine out of truck) and wouldn't loosen with impact. I did manage to get it loose with a breaker bar on an extention and shocking it real hard with a 4 pound hammer. Why it wouldn't back off with my 250 pound impact I don't know...but sounds similar, it was stripped. I verified with my buddy, who I bought the dead truck from, that when he first got it and had some work done, on driving it home from the "mechanic", the harmonic balancer flung completely off and it was obvious they had cross threaded the bolt putting it all back together, because he said it always had wobble on the serpentine belt (5.0 Mustang motor) and I had noticed the balancer sitting a little too far forward with the dead motor in the truck anyhow. Was no big deal, because I wasn't planning on reusing the engine. However, from what you describe, I dont' think you did any damage, someone BEFORE you must've cross threaded it and you "might" be ok with tapping your threaded crank and using a new bolt, good luck, Brett.

UPDATE: I was able to get the bolt out a little bit ago by working it back and forth with the impact. The last 4 threads or so on the bolt were f-ed. Threads in the crank don't look too good either :mad: I am taking the parts to the local speed shop now to get another balancer ordered and figure out what to do with the threads.....

Get a big bar and crank that sucker out. Just hope that you can clean the threads up and get a new bolt in there.

Kev

If you can chase the internal threads with a thread chaser tap and they are OK you're all set. Sometimes a longer bolt can get to good threads deeper in the hole. If they are bad you can easily install a helicoil or go up to the next size bolt. You probably have a 7/16 in th SB so you could go up to 1/2.

Ditto on what RM said. Run a thread chaser in there and clean the threads up on the crank. DON'T USE A TAP! Here's the thread chaser set I bought from Sears on sale last year. Well worth the money. I chase all the threads on my motor before assembly and clean-up.

Sears item #00942275000.

I guess I'm going to learn something new here...I've always used regular taps for chasing threads...what's the difference between a regular tap and a thread chasing tap?
Thanks

Thanks guys! RM, it is a Big Block, so I think it has the 1/2" already. I am going to get a tap or thread chaser and do what you suggested when I get a chance. I think I can rescue it. Temperature outside dropped from 71 today to 35 right now - and we're supposed to get lots of ice and snow tomorrow so I won't be working on it for a while....(have to have garage door up to work on it)

After I got the balancer off - it became apparent why I was having problems. The balancer had marks on it where someone previously tried to beat it on with a hammer ( which kind of buggered up the flange on the underdrive pulley) and the outer ring was slipping. The balancer bolt was an ARP, our guess was that someone tried to beat it on dry and then used the bolt to press the balancer on.....I won't make that mistake :D

Drive WFO - I also have the same question as S M - what is the difference between a tap and a thread chaser?? Why do you say not to use a tap?

thread chasers will NOT remove any metal taps MIGHT remove metal thats about the only real difference as far as I know...personally I have always used taps to clean threads with seemingly no ill effects:)

Taps will remove material and cut threads which is what they were made to do. Chasers straighten and clean threads more than cut. I use taps alot too but say you clean the threads in your motor for the head bolts with a tap instead of a chaser. Much more likely to leak no matter what sealer you use. There's just less material cause the tap cut some more out when you used it. RM

Taps will remove material and cut threads which is what they were made to do. Chasers straighten and clean threads more than cut. I use taps alot too but say you clean the threads in your motor for the head bolts with a tap instead of a chaser. Much more likely to leak no matter what sealer you use. There's just less material cause the tap cut some more out when you used it. RM

yes a tap will remove metal if there is metal to remove, such as when you tap a fresh hole, but if you are using the correct size tap in an already tapped hole IMHO it should not be removing any metal unless the threads are damaged somewhere in the hole...with an undamaged thread all it should normally be removing is the dirt in the threads...again just my two cent on this:)

such as when you tap a fresh hole

I'm not even gonna say anything :D

I guess I'm going to learn something new here...I've always used regular taps for chasing threads...what's the difference between a regular tap and a thread chasing tap?
Thanks

Same here, I will use a bottoming tap vice a taper for existing threads. I am not sure I know or see the difference in using a thread chaser.

Get the opinion of a machinest that you can trust (someone that really knows what he is doing, not someone that just tells you he is a machinest) and i think you will find that the majority will tell you not to use a tap to chase threads because it enlarges the hole too much, a thread chaser just cleans up and reshaped the exsisting threads back to their original shape like Real McCoy said.

I guess I'm having a hard time understanding that if I tap a hole with a 1/4" tap and later come back and run that same tap through the hole again, how's it going to remove any more material (other than dirt or other contamination) when there's no material there? What am I missing? I guess I'd have to look at a set of them and try to see the difference from a regular tap.

I am not expert on this matter but my understanding is that the threads distort slightly when the bolt is tightened and do not completely go back to their original shape even after the bolt is removed. The tap cuts this distortion out but a thread chaser just reshapes the metal back to its original shape. Like I said, not an expert but that is how it was explained to me many years ago.

In 90% of the cases it will do what you need (tap),but if you have a damaged thread it will cut it out with the tap the chasers are designed to realign threads.If you have a thread that is damaged,gone oval (extreme case)and the hole was 3/8" the wide part of the oval is over 3/8" and the narrow part is under the tap will cut the undersize to 3/8" while the larger part of the oval will remain larger you now have a hole that is larger than 3/8" as well as possible head leak as previously mentioned by RM.the chasers are not designed to cut,but push the metal back into the correct shape,and realign threads.

Sorry for the lack of tech terms but that's the simplest way to explain it.;)

For the most part a tap will do the job,but you only need to ruin 1 block to find out the $30 you saved just cost you $3000 cause the wrong part let go.
When you do this for a living the right tools are needed.I'd be P!****ed to find that my engine build damaged my #'s block for not using the right tool.

You can take a steering wheel of with a hammer too(I've done many without ill affects),but mess it up and you damage the column.I know i have one from the a previous owner.:(

My 2 cents Paul

You can take a steering wheel off with a hammer too(I've many without ill affects),but mess it up and you damage the column.I know i have one from the a previous owner.:(

My 2 cents Paul

Funny stuff there Paul:D ......however I have engine blue printing books that say taps are fine for this purpose but I dont think I have any chasiss dissasembly books that say a hammer is fine for removing a steering wheel.:rolleyes:

I'll have to agree with using the taps as opposed to hammer for steering wheel removal:p ,just trying to show an example and I went to the extreme:eek:.
For the most part taps are fine I've never had any trouble using them.

Does this mean you won't need me to remove your steering wheel? LOL!!!

Paul

I gave you my thoughts and if you have had good success with taps that's fine,Tap the holes. I have done lots of stuff others have told me I shouldn't. I won't argue about it........LOL. The post was how to remove the balancer and then fix the threads. He now has options and for this job either method will do the job. On some BBCs I've used 9/16 bolts so if all else fails go up a size. You still have helicoils and threaded inserts too. Best of luck. RM

Thanks everyone! I think I will try to find a thread chaser first - if I can't find one of them I'll try the tap idea and go from there. I won't be doing it until it warms up a little though ;)

I think the point is that taps will clean out (and slightly enlarge) threads that are good to begin with. When the threads are damaged and are moved where they should not be, a tap will just cut them off and leave you with thin or no threads in the damaged area. The chaser will push the threads back where they should be. This leaves the threads stronger and they will not damage the new bolt like sharp or missing threads can.
As a Gunsmith, I tapped and threaded hundreds of holes and repaired damaged ones. Your wise to use the thread chaser, you don't want to launch the balancer thru the radiator at 7000 RPM.
Be sure to clean the hole out well with some brake cleaner and then use some anti seize on the threads of the new bolt. Use a good high sulpher dark tapping oil ( not regular oil ) on the thread chaser will make for nicer threads, don't put in in dry (you should know that from other experiences ;) ). Clean the hole before using the thread chaser also. You are going to want to back the thread chaser out from time to time and spray more brake cleaner in the hole to clean it out. Use lots of threading oil, get a good tap wrench and apply even pressure streight in, do not lean on the wrench. If for any reason the tap stops or binds, stop and carefully back it out. If the tap breaks in the hole, the're murder to get out. Take your time and do it right. Cranks are very hard and tapping new larger threads is not an easy process.

John K

Hi,

Lots of good advise on this already.

In my opinion there are several types of taps as well as thread chasers. Some are much better at "forming" threads than cutting them. For cast iron I have had good luck with the forming types of tooling, but alloy steel may be a different matter. Some of the tolerances on the chasers leave a lot to be desired, but they generally get the job done. When you are are done I would thread a new bolt in and see how it fits if it feels "loose" I would be kinda sceptical about it.

I have Helicoiled several crank snout threads. I have made a few fixtures to help align the tooling, that makes it simpler and more accurate. I use two helicoils in this application, or you may be able to order 1 long one. The point is you want as much thread contact as possible. I have had excellent luck with using two coils.

How ever you repair it be very careful installing the balancer.

Good Luck
Jeff

I think i will get the tap situation figured out for yas

First there are two taps, regular and bottoming, a regular tap is tapered and a bottoming tap is the same diameter the whole length...

A thread chaser is not designed to cut new threads, just clean em out and straighten things up....

The problem with a standard tap (most people do not own bottoming taps) is that in a blind hole you can't tap all the way in....you could with a bottoming tap, and if your cleaning threads in a blind hole i would use a chaser over a bottoming tap....and in general the reason i personally use a chaser over a tap is because i don't want to use my good taps just to clean out some raggedy old holes, i use them for good cuts on a fresh hole so the tap cust cleaner and faster with less chance of breaking, the other reason i like to use chasers

I have bottoming taps and starter taps and I don't think the bottoming tap is any different than a starter tap except one makes threads all the way down a blind hole while the other doesn't. Then nobody has mentioned a two, three or four flute tap. Whats the difference and when do you use the different flute types? Then we have taps with different size shanks. I know what the tool reps who use to sell them all to me use to tell me they were for. I doubt any of us know as fact what the differences are for and we all have different thoughts and opinions. I say just do whatever works and makes you happy. RM

Thanks for the good info, I'll be checking out my crank this weekend - my balancer almost came off a few months ago. It cracked the entire length of the keyway, boogered up the crank snout around the keyway. I was able to file it down a bit and snug another balancer onto it to get it from the trailer into the garage. I have not touched it since Sept. 2, but 'should' have time this weekend. I didn't even get to check the balancer bolt threads, but now I'm armed with info ;)

Anyone ever see a balancer break open like that? Luckily it didn't happen the day before when I was running 7,000 rpm through the traps :eek:
Will keep you posted.
M

People may get into some trouble when they use the incorrect tap or die sets.
There are different "class" of thread fit. 1/2/3, A/B/C.
Class 2 fit is a common industrial standard. If you use a class 2 tap (or unknown poor quality import) on a class 1 thread it will remove material.
Taps and dies are ok for cleaning threads as long as the class fit is the same.
And you do not enter vergin/untapped material.
I inspect suppliers hardware threads at work. This is why I have to inspect threads (internal and external), nut and bolt threads with calibrated, and class matched, plug gages and thread gages. I cannot use a nut to check a bolt thread. Nor could I use a tap to check a nut.
It has to do with pitch, angle, pitch diameter and several other characteristics, plated and unplated factors also.
IMO.....Threads/screws is a complicated engeneering discipline. Some people study to get degrees in "thread engeneering". I'm not one of them!!!

Don

I found the correct thread chaser from one of the mechanics at work and ran that in the hole, then took a new bolt and put it in without the balancer. It seemed to tighten up well - so I hope everything is cool. I bought a 2" long bolt along with the stock 1 1/2" - so if I can get away with it I will just add a washer and lock washer to the 2" one to get farther down in the hole when I install the balancer. the hole is 1 1/2" deep, then you have about 3/16" for the main washer, and I'm sure the balancer doesnt fit exactly flush either - so maybe I can use the 2" one to get more of the threads. Hopefully I will get this done in the next couple of days......

I have a 250 straight six which I am currently restoring. I would like to pull the balancer in order to clean the front of the motor. The question I have is that the center of the balancer is not threaded. I know I can pull it but how do you press it back on with nothing for the puller to grab on to? Any help would be appreciated. Happy Holidays! Billy


http://www.cardomain.com/ride/2447606

The puller bolt goes into the crank threads.

Thats what I thought normally would be the case but my crank does not have threads. It has a cone shaped hole in the center. There is nothing to thread into. Thanks.

Hmmm. Normally when installing a balancer you would thread the stud into the crank. Then you would use the large "nut" to thread onto the stud pulling the balancer onto the crank.

Normally a crank has a "cone shaped" hole which is actually just the thread hole that has been countersunk. Are you positive there are no threads in the crankshaft? That's where the bolt goes that holds the balancer on the engine.

I will check again tomorrow but I looked pretty closely today and could not see any type of thread. I check back tomorrow. Thanks.

Early engines didn't have balancer bolts they just pressed on. Everyone and I mean everyone used a BFH to install balancers. Bolts were installed in the later 70s engines. I think you have two options. You can tap the crank hole so you can use a bolt and an installation tool or you can do what everyone did before the bolt. Beat it on with a BFH. RM

BFH! LoL:D

I hate to see a balancer hammered on. I didn't know that about early engines. Interesting.

Early engines didn't have balancer bolts they just pressed on. Everyone and I mean everyone used a BFH to install balancers. Bolts were installed in the later 70s engines. I think you have two options. You can tap the crank hole so you can use a bolt and an installation tool or you can do what everyone did before the bolt. Beat it on with a BFH. RM


You're kidding right?

What year did they start putting threads in the center hole for the balancer/pulley?

I have a forged GM crank that's threaded, I thought my crank was from an L78 396.....maybe not?

Also wouldn't hitting the balancer on with a BFH hurt the bearings??????

I would try to drill & tap the crank first, second option is to us e a 2x4 against the balancer and beat it on with a BFH. Second option is the norm, but not recomended.

KenDog

Hi,

I agree that a lot of early engines were not taped. I think all big block cranks are taped (Im not referring to 348-409 style). I think in the 60s only "Special High Performance" and heavy duty style truck engines came with the crank drilled and taped.

If it were me I would "carefully" drill and tap the crank and pull the balancer on. Its a good safety feature as well.

Good luck

Jeff

If you don't drill and tap the crank, make sure the crank nose and the inside of the balancer are clean and smooth and heat the balancer to about 200 degrees before putting it on with the BFH. I don't think that you should get it any hotter or you might ruin the balancer.

John K

When I went in the Army in 1966 there were no bolts in the cranks on any GM cars I saw and worked on. My 62 model 340 HP 327 didn't have one. I lost a balancer once and we drilled it to keep that from happening again. It never hurt the bearings to use a BFH to install the balancer and back then they didn't make cast cranks, all the cranks were steel. They went to the bolt while I was in the Army cause when I got out we installed a cam in my buddies new Z 28 and it had the bolt. My best guess is the bolt came out in the mid to later 60s. Everyone I know pretty much used the BFH method for installing balancer until the 80s when someone made a installer tool that people could afford to buy and advertised it. Now everyone thinks that a BFH is a terrible way to do it. If I didn't have a tool I'd use a BFH in a skinny minute but I don't suggest everyone else does. Tap the predrilled hole and buy a tool. RM

Hello.

I think RM may be right about the 340hp 327 not being threaded, but it seems to me the 350hp -365hp series starting in 65 may may have been the first hp style to threaded. I think the big blocks started and in 65 and I think they were threaded.
As far the any GM cars goes I think a lot of the Buick-olds- pont etc- used bolts in the early 60s as some had "slip" fit style balancers, These generally use a very large bolt (5/8-3/4?).

As far as "hammering" the balancer on that is the way it was done. I have factory Chev service manuals, showing how to do it. If the engine is out, and you have room to swing the hammer, the "bigger" nylon style dead-blow hammers are great. They generally wont damage the balancer at all.

If engine is in the vehicle its a bear no matter what.

A little oil on the surfaces helps and I always add a small amount of silicon in the keyway to help prevent oil seeping through.


Good Luck

Jeff

In respect to Six's I would read the pages in Leo performance book on proper removal of a Harmonic balancer.

Thanks for all the heads-up advice. If I may sound stupid and ask a small question? What is a BFH hammer? Its probably something simple but I'm just not getting it. Thanks!

http://www.cardomain.com/ride/2447606

Thanks Fred! I have Leo's book sitting in the draw and never thought to look. Thanks again.

http://www.cardomain.com/ride/2447606

Big f..kin hammer = BFH. Merry Christmas. RM

Thanks RM, My friend called me just before you posted your reply. I told him the initials and he proceded to tell me how slow I was. (HaHa). At least I got 1 intial out of 3! Thanks again!

http://www.cardomain.com/ride/2447606

Ummm..... It just means BIG hammer:D

Checked my crank threads this weekend, they appear fine - thankfully! The keyway area is not so lucky - but something did this to my balancer :eek:
Any ideas? I'm thinking a loose bolt.
M

http://i61.photobucket.com/albums/h68/aacorp/Balancer.jpg

Well tonight I drilled and tapped my crankshaft!! With the engine in the car! Documented exactly what I did. Couldn't have gone any smoother. Worked out great!

http://63nova.nextmill.net/tapcrank/

http://63nova.nextmill.net/tapcrank/cimg1474_web.jpg

I just want to add a small bit of advise to this drilling and tapping issue. Please if your drills flutes are 5 inches long do not use all 5 inches.
Funny or not I got a phone call one day from a friend who was helping his neightbor do this and he said that the neighbor drilled all the way though.
I had to go see and damned if he didnt drill all the way through the crank. probly a rod too knowing this guy. :confused:

i just put one on on a 250 l6 and it was farely simple all did was after i put the engine in i already had the grill and radiator out so i put a jack between the bumper and balancer and just jacked it on with a scissor jack

wicked long thread about threads! Looked at the procedure that brianlewis did and it looked great! Way to forge ahead! Thanks for taking the time to document and provide a solution to a long standing issue of BFH's and the old 327's without the bolt. They are the only ones I have had to deal with that have that problem. My 65 396 was threaded and so have all the motors I have owned. Great thread, great input, great site. Thanks for everyones take, I learned a lot.

Keith