drivehaft update *part 3*

[66chevyIISS]

Well I finally got the car in the air and got to give it a full inspection. I think I found the culprit! Tranny blew before the drivehaft? Looks like I got more work ahead of me then I was hoping for.

I don't think you're supposed to see the converter through the transmission housing!

http://i53.photobucket.com/albums/g55/66chevyIISS/cracked_tranny2.jpg
http://i53.photobucket.com/albums/g55/66chevyIISS/cracked_tranny.jpg

______________


Here is the other damage:

http://i53.photobucket.com/albums/g55/66chevyIISS/driver_smashed.jpg
http://i53.photobucket.com/albums/g55/66chevyIISS/hole_floor.jpg
http://i53.photobucket.com/albums/g55/66chevyIISS/Passenger_smashed.jpg

[novas4life]

GOOD LORD!!:eek: WOW, sorry about the carnage.
Brandon

[66chevyIISS]

ya, thanks :( I'm scared about the engine now too! Guess I will be removing everything now to fully check things out.

[69NovaSS]

Man oh man....you just inspired me to add the installation of a driveshaft loop to my list of upgrades...hopefully the motor surived undamaged :)

[novaboy009]

66ChevyIISS, you are why I got a loop:).

Kev

[FunkyNova66]

Did the rear or front u-joint break? Looks like the rear came apart in which a drive shaft loop wouldn't help much. How did you crack the trans casing? You might check to see if a weight came off the flex plate. I have seen this cause tranny casing carnage.:eek:

Let us know what you find out.

Good luck
Dave

[69NovaSS]

Im not sure either ujoint broke...the drive shaft did break in 3 pieces which allowed the back and front peice to beat up the floor pretty good...

first thread:
http://stevesnovasite.com/forums/showthread.php?t=32939

Second thread:
http://stevesnovasite.com/forums/showthread.php?t=33341

[66chevyIISS]

Both joints are still intact as you can see in the pictures of the other posts. It all went haywire just as I was lifting at the finish line. The only thing that would have saved the underside of my car would of been a shaft loop towards the rear. The rear u joiint and shaft were still bolted to my rearend so when it snapped it just whipped around until I could get the car stopped. I don't know what went first. I guess it's possible when the driveshaft snapped it got wedged in the transmission tunnel and tweaked the tranny? I will drop the transmission pan today and see if parts drop out....

[FunkyNova66]

:eek: :eek: that's right! I forgot it twisted it into 3 pieces...I remember the first thread. WOW. I would have shat my pants.:eek: :D Keep us posted on what you find. It may help put this mystery together.

Dave

[JRChevy]

Both joints are still intact as you can see in the pictures of the other posts. It all went haywire just as I was lifting at the finish line. The only thing that would have saved the underside of my car would of been a shaft loop towards the rear. The rear u joiint and shaft were still bolted to my rearend so when it snapped it just whipped around until I could get the car stopped. I don't know what went first. I guess it's possible when the driveshaft snapped it got wedged in the transmission tunnel and tweaked the tranny? I will drop the transmission pan today and see if parts drop out....

I'll come by and gawk and drink beer while you check it out:D :beer: :beer:

Let me know if there's anything I can help with:rolleyes:

[Real McCoy]

The same thing happened to my brother with my old Nova in Ohio. The theory he had was the trans cracked when it launched. He said there was parts of the bell housing laying on the track around the 60 ft clocks so that's what he thinks hapened. It stayed under power with no vibration til he got to the finish line then it all exploded. He thinks the trans dropped down finally which shifted it into reverse and that's when the driveshaft twisted up and also broke in 3 peices. He was running 130 MPH when it broke. That car has front and rear loops but the driveshaft still took out all the mid floor and tunnel plus gashed a hole in one of the 2X3 frame connectors. He said after he changed his drawers due to his bowels discharging unexpectedly he started to have people bring him all sorts of parts found on the track. The rear of the shaft was still bolted to the rearend which kept turning and whipping which did most of the damage. He now has an Ultrabell, motor plates and a moly driveshaft. This happened to him about 3 yrs ago. RM

[69NovaSS]

He said after he changed his drawers due to his bowels discharging unexpectedly. RM

RM, that is one of the funniest and cleanest ways I have ever heard that described...ROTFLMAO.....lol:D :)

[JRChevy]

Depends should be a mandatory part of the safety equipment requirements!
http://www.depend.com/offers/images/whats_new_204x183.gif

[66chevyIISS]

I think we get the point John !!:D


Real McCoy,thats real interesting. The way you describe it sounds almost identical to my situation.

[JRChevy]

Waddya mean 66??:p

[LIL NOVE]

sorry 66, but i havent read the other threads. what RPM's did u leave @ and were u on the bottle, (do u even have one??). im about to take my car to the track, and u seriously got me scared. im about to crawl under the car, and check for any weak points. sorry to see that happened......

JOHN

[66chevyIISS]

I launched from idle and not at full throttle. It broke at the finish line around 111mph. No nitrous on my car. What happened to my car I wouldn't call normal. I would definitely check all nuts and bolts on the car its always a good idea. I always try to tighten everything before I go to the track.

----

I got my pan off and it looks better then I was thinking. There was only 4 piece of really thin metal in it and I guess that could have been from anything at anytime. I have a spare th-350 thats just stock. Should I swap out all my salvagable parts from my current th-350 (hd sprag, steel gears, shift kit etc..) and rebuild my spare or do you think I need to upgrade to a th-400?

pan metal 4 pieces top right:
http://i53.photobucket.com/albums/g55/66chevyIISS/trannypan2.jpg

[1BluII]

I'm glad for you that your exhaust took the hit and not your fuel line. My setup is very similar (except I have a Muncie) and now I'm rethinking the whether I should convert to the L79 style fuel line routing instead of the "regular" routing. Of course, I just bought the new stainless line last year...

I'm thankful you weren't hurt - mechanical stuff, though expensive, is a drop in the bucket compared to what could have been.

Keep us apprised of developments - it's helpful to many of us to learn this stuff.

[66chevyIISS]

yes, if my wheel had ran over the parts falling out from under my car it could have been a very different outcome. Thankfully I only have the problems I have.

my fuel line is routed along the outside of my subframe connectors away from moving parts. The line you see in the pictures is my rear brake line :eek: It was saved by my muffler!! If that muffler wasn't there I am positive it would have been taken out.

[1BluII]

ah, I forgot the 66 - 67 brake line routing is different (my 67's goes down the driver's side inside rocker), I now see the fuel line attached to the inside of your passenger side rocker. Either line would be bad, though!

Glad you're ok, thanks for sharing the pictures and info.

[Bill's II]

Hey Now. I had a similar thing happen. The real culprit? Torque Converter. It balloned and locked up everything. Just a thought. Respectfully, "Bill's" II

[Raymond]

You're lucky to live and tell us about it,I hope you pray at night!!!!!!!!!

[kirk]

Hey there 66, are you running solid motor mounts? How about tranny mount? A buddy did the exact thing to his car, a A body in a street race about 6 years ago. I don't recall if his driveshaft was the wrong length or out of alignment, or if he lost the balance weight, but there he sat. with a grenaded trans and 3 piece driveshaft. Make sure you get a good driveshaft and have it balanced, and double check the alignment of the driveshaft at the tranny and the rearend when you get ready to put it all together. Good luck,

Kirk

[DrDenny's 69 Rat]

Dude...That is way RAD. I did a similar episode, in my 67 Chevelle. But it was my rearend that blew , locked up, WFO, broke the trans in half and spit the driveshaft out the back. Beat the crap out of the exhaust and all that good stuff.

Good luck,
Denis

[kilowatt]

just wondering if you were using the original shaft in the car and if you've ever heard of the term critical speed? the original shaft would have been
2 3/4 dia. and i think about 52 1/2 long. i work at dana's r&d facility for testing driveshafts and axles. the calculated critical speed for your shaft is about 4600 rpm with a 75% safety margin. with that i can say with some
certainty that your shaft probably hit critical speed at 6100 rpm. when a shaft enters critical speed and stays there with the right conditions it will explode like a small bomb. this explains why the shaft is still conected at both ends and is in 3 peices. the best way to fix this is use a larger dia. steel shaft or better yet aluminum. the longer and smaller the shaft, the lower the critical speed. if you take two identical shfts, 1 alum and 1 steel the alum shaft will have a higher critical speed. this is why some trucks use aluminum 5 or 6 inch shafts.I was able to fit a 4" shaft in my 67 with th-350. now i use a 3 1/2" alum. with 1350 joints .the 3 1/2" shaft is good to about 8200 rpm. critical speed is affected by length and dia. and since we can't make it shorter more dia. is the only answer. the same thing happened to me in a '80 malibu, i shifted into third gear and KFB! it ripped the trans off the motor which i think is what happened to you. i hope this info helps, kilowatt

[Real McCoy]

Pretty good info there kilowatt. I enjoyed that. RM

[69NovaSS]

just wondering if you were using the original shaft in the car and if you've ever heard of the term critical speed? the original shaft would have been
2 3/4 dia. and i think about 52 1/2 long. i work at dana's r&d facility for testing driveshafts and axles. the calculated critical speed for your shaft is about 4600 rpm with a 75% safety margin. with that i can say with some
certainty that your shaft probably hit critical speed at 6100 rpm. when a shaft enters critical speed and stays there with the right conditions it will explode like a small bomb. this explains why the shaft is still conected at both ends and is in 3 peices. the best way to fix this is use a larger dia. steel shaft or better yet aluminum. the longer and smaller the shaft, the lower the critical speed. if you take two identical shfts, 1 alum and 1 steel the alum shaft will have a higher critical speed. this is why some trucks use aluminum 5 or 6 inch shafts.I was able to fit a 4" shaft in my 67 with th-350. now i use a 3 1/2" alum. with 1350 joints .the 3 1/2" shaft is good to about 8200 rpm. critical speed is affected by length and dia. and since we can't make it shorter more dia. is the only answer. the same thing happened to me in a '80 malibu, i shifted into third gear and KFB! it ripped the trans off the motor which i think is what happened to you. i hope this info helps, kilowatt


THAT is really good info...thanks for sharing:)

[the FLYER]

i was thinkin' along the lines of what Kirk mentioned... could the engine's torque done this ??? i'm referring to the mounts ??? if it twisted/torqued a lot on launch, couldn't it have done this damage ???

55 chevy's mount the engine off the front and tranny off the sides of the bellhousing, which in my head is better than the two side mounts on engine and the center tailhousing mount... but i really dunno...


still looks Real Nasty...

[NOVACA1N]

66chevyIISS, depending on how far into the tranny it broke, you may be able to put on an ultra bell. I know a few people who have done it, but I'm not sure if that's too far.

EDIT: Never mind, I didn't read the whole thread ;)

[66chevyIISS]

rubbing salt in my wound here!! :D

thanks for the reply kilowatt. That's similar to what people who built my driveshaft said. It was a stock shaft that had 1350 ends put on and rebalanced. What makes me mad is they knew what it was going in before hand, but didn't warn me. Why would I put 1350 ends on a stock driveshaft if they thought I wasn't going to be racing it. If they told me this driveshaft will explode on you then obviously I wouldn't have used it!! I have heard other people running stock shafts and not having any problems so I didn't know what to believe. Its good to hear this from you though. I know for sure I won't be replacing it with a stock unit!

[kilowatt]

:shh: driveshaft critical speed is a fairly exact science but is also affected by outside forces like balance, temperature, shaft angle, torque, shaft condition, and the condition of the joints. the main factor is how much mass the shaft has and how is it supported. all shafts have some amount of runout. so if a 60" shaft is only suported by a u joint at each end and has .005" runout,when we start to turn it cetrifugal force starts to act on the shaft. the faster it spins the bigger the problem. sooner or later the shaft is bent like a pretzel at a very high frequency. if you take the same shaft and shorten it, it becomes harder to bend which resists the cetrifugal force. the same is true to a larger dia. tube. try bending 1/2" tube then try to bend 4" tube. the 4" tube is naturally stiffer. the advantage of aluminum is less mass which means less centrifugal force. the slow motion video of a test showed the shaft swinging back and forth by up to 2" !! i think most stock shafts are right on the edge of failing at common trap speeds above 6000 rpm. some do and some don't. my shaft failed, i think yours did too. kw:)

[DrDenny's 69 Rat]

That was some great information!
Thank you,
Denis

[66chevyIISS]

I've been kind of slow on updating this. I really haven't been motivated to work on my car since I don't have the money to replace everything right now. I took the tranny out today when I got home from work. Once I unbolted the converter it dropped straight down.

http://i53.photobucket.com/albums/g55/66chevyIISS/broken_tranny2.jpg
http://i53.photobucket.com/albums/g55/66chevyIISS/broken_tranny.jpg
http://i53.photobucket.com/albums/g55/66chevyIISS/flexplate.jpg

[Justin66]

Dammit to hell :eek:.

[66chevyIISS]

can anyone tell me more about this bellhousing? Jegs has them for $219.99. It says "bolts onto the front pump for easy installation" is it really "easy? you would think something like that should be welded?

http://www.jegs.com/webapp/wcs/stores/servlet/CategoryDisplay?storeId=10001&catalogId=10002&catalogIdentifier=&categoryId=18243&parentCategoryId=10533

[nova10sec]

Those bells are great. Use a cutoff saw to even out your broken one. Then you truley bolt it to the pump via longer bolts. My car does not have one but a buddy has one in his vette. The coolest thing is that you gain a ton of clearance between the bell and the floorpans. Anyone who has ever tried to install a flexplate shield knows that it will take a day of beating up the trans tunnel/firewall to get em to fit..

By the way, you are luck you foot didn't get taken off when it let go.. PS- your next investment should by in a trans shield (goes around the gear sets) They do explode and have gone clear through the roof of cars....

[Real McCoy]

I posted earlier that my brother experienced the same problem. He now has an ultrabell and I have one too. It uses the front pump bolts to attach it. It looks kind of weird and doesn't seem like it can alighn itself but after 5 yrs of use ,and I swap transmissions using just one ultrabell, it's not given me any problems and 4 or 5 of my buddies use they too. You can cut the old bell off with a sawsall then use a small 4 inch grinder to smooth it out. The ultrabell seats against the pump face anyway. RM

[DrDenny's 69 Rat]

Back when I had my Camero and Vega, I had a clutch turbo. It was a TH400 with a lakewood scattershield that bolted to the front pump, and you used a flywheel, pressure plate, t/o brng, and there was a drive unit that went from the pressure plate to the front pump. It was bad ***** in it's day. Leave at whatever RPM worked best, and the nastiest shifts you ever felt. ;)

[Real McCoy]

We put a clutch turbo in my buddies 69 Chevelle with a 427 back in 1971 or so and it was bad. It was all stock and the thing would twist up so bad it looked like it was going to break in half when it launched.......LOL> RM

[Bill's II]

Hey Now. I agree get the ultrabell and installl a clutch turbo. I have used them both and no issues. At one time we used the cluth turbo on a circle tracker with pwrglide. It would haul the mail especially at PIR coming off the corners. Also used clutch turbo on a 727 torque flight. It worked really good and made times more consistant with reaction times in the .065 to .080. Now only you can decide what and how to fix what you have. respectfully "Bill's" II :)

[Real McCoy]

I was just talking to a buddy and he told me that another friend of mine had his P/G explode Sat night while racing at Jefferson Pageland. I haven't talked to him personally yet but I think when I do he'll say he had the same failure as we have been discussing. RM

[Justin66]

I have never heard of this clutch turbo setup. Could someone give more info on this setup or maybe a website where I could see or read about this? I have a th-400 that needs a bellhousing crack welded up. I could get a Lakewood bellhousing for it and try this out.

Is this clutch turbo streetable? What kind of torque can this setup withstand? Im assuming as much as the clutch can take as long as the trans holds together.

What connects the input shaft to the clutch some kind of coupler or is there a certain clutch made to work with automatic input shafts? Are these clutches still readily available?

This has really sparked my interest as you could probably tell. I needed to change converters anyway or at least have mine adjusted. The clutch setup I could choose my own launch rpm and not worry about a muncie blowing it guts all over the track.

[DrDenny's 69 Rat]

All I know is that Lakewood had the scatter shield, and McCloud had the clutch parts when I had mine.

Denis

[Real McCoy]

I have no idea where you might find the stuff to do a clutch turbo today. You could try calling a speed shop in your area. I haven't seen anyone use one in years. The trans brakes made them obsolete and outdated. RM

[Justin66]

Well thats a start. Thanks! :)

[Camgrinder]

I had the same bellhousing failure in my '65 Nova. I didnt have enough clearance between the yoke and tailshaft of the transmission.
1st pass with a new engine, shifted to 2nd at 8000 and the car started vibrating. clicked it into drive at 6500 and started to lift easy. I thought I had a broken rear u-joint that was still stuck in the rear yoke. Still ran a 12.18 @ 118!
The local driveline guy said I had a powerglide yoke instead of a th350 yoke. The th350 yoke has more clearance. Lucky for me the driveshaft didnt break.

http://drcamshafts.com/5/65th350.JPG