Vibration at 55-60 mph..... [Archive] - Chevy Nova Forum

: Vibration at 55-60 mph.....


ovrdrive
2nd-June-2010, 09:11 PM
As the thread title indicates, I have a vibration from the rear section of the car. I can't actually feel it but, the rear view mirror is shaking like crazy. The rpm range is around 1800-2000 if that helps.

Ok here is my car and the items I have installed on it.

355 cid XE-274H-10 cam
200-4R with 2200-2500 stall
4.11 posi rear end
stock drive shaft with heavy duty u-joints
Ultra flow mufflers with x-pipe

This vibration doesn't happen at all speeds, but it is very noticeable at 55-60mph. I was thinking of the following:


Wheels are balanced to 55-60 by the local shop which has a Hunter Road Force" balancer.

Axle or carrier bearing going bad. ( But wouldn't that symtom be thru all speeds?? )

Improper shimming of the ring and pinion gear ( When installing the gears, the yellow contact patch was dead solid in the middle of both the ring and pinion gears )

unbalanced drive shaft

U-joints going bad




I had the car on the street for about 6-8 months and I am trying my damndest to figure it out. If there is something else that I might have overlooked, please let me know...

big dog ss
2nd-June-2010, 09:18 PM
can you rotate your tires?? if so try that and see if it changes at all...

ovrdrive
2nd-June-2010, 10:06 PM
Running different sizes front and rear. Great idea though to see if the vibration disapears...

Rbace123
2nd-June-2010, 10:21 PM
Where you at in MD ? I have a 66 and have had vibration issues from the day I got it. Messed with everything there seems to be to mess with and it is still there sometimes. It may have got better but then again I may have got used to it also.

ovrdrive
3rd-June-2010, 07:09 AM
Rbase123,

I am located in Southern Maryland about 40 minutes South of Waldorf.

Tomorrow, I am taking the rear tires to get re-balanced to ensure there is no vibration there. And tonight, I will crawl under the car and verify that there is grease in the u-joints.

nova75mike
3rd-June-2010, 08:03 AM
Take your driveshaft and have the balance checked on it. Had the same problem on my 75. Mine was around 45-50 mph, sounded like a bad u-joint. 3 sets of joints, countless tire rebalancing, and tearing the rear apart to have everything checked......and it turned out darn driveshaft was out of balance. A truck shop close to work charged me $10 to rebalance the shaft.

tvnl
3rd-June-2010, 08:40 AM
Yea first you need to figure out if it's a tire/wheel vibration or a driveline vibration.... A tire vibration will be of a lower frquency than a driveline vibration.... Most times a driveline vibration will make kind of a humming type noise as well.

ovrdrive
3rd-June-2010, 01:49 PM
Todd,

good point and thanks. But, with my Magnaflow exhaust, I am uncertain if it's a low or high frequency. The only thing I have to go by is the vibration at the mirror. I could put some pieces of rubber between the mirror mount and the car but, I need to find out what the heck is going on....

novaconv63
3rd-June-2010, 03:04 PM
I've had my wagons wheels balanced three times. Still feels like wheels are out of balance. Feels like the front end shudders. Everything up front has been replaced and aligned and it still does it.Starts at about 50 gets more noticeable the faster I go. I put a new trans x member in and rubber trans mount. This got rid of the noises, but not the vibration. Sounds like we need some Divine intervention here. I guess next step for me will be driveshaft balance.

Rbace123
3rd-June-2010, 03:13 PM
I have been there and done it all. Rebalanced tires several times, new drive shaft and balanced 2 times. Moved pinion angle all over the place. Jacked car up and ran on jack stands ( no vibration ). Going down the road sometimes at 65-70 feels like something is going to come thru the floor. I can feel mine in the shifter not the front end. Like I said I either got used to it or it got better. Do a search for vibrations. I got a lot of good information but never totally solved the problem.

TomM
3rd-June-2010, 03:29 PM
One trick you might try, if all else fails. Take the bolts out of your torque converter, and rotate it one bolt hole, and reinstall the bolts. I had a vibration on mine and the tranny guy told me about this....and it worked. I thought he was FOS, but he is an old school hot rodder, and been building trannys for 30 years......

Something about the flexplate and converter not actually being "balanced" together...but hey it worked, so go figure......remember which way you moved it, so you can move it again the same way of it gets better, or put it back if it doesn't.

My vibration was right around 50 to 55 too.....

Also, check your rear u-joint carrier to make sure it isn't cracked, if you had your rear end rebuilt, and make sure your driveshaft is engaged correctly in the tranny, too far out will cause a harmonic vibration like you describe.

T,

ovrdrive
3rd-June-2010, 09:04 PM
Ok,

as of this evening, here is what I have accomplished:

Marked all 3 torque convertor bolt holes along with the flywheel holes and moved the convertor 1 hole. Then retorqued the bolts.

Loosened all 4 bolts to the driveshaft, spun the shaft 180 deg and reinstalled it. And retorqued the 4 bolts

The rear tires are off and going to the shop tomorrow for a spin balancing.

The car is still on jacks, ( and wheel chocked ), should I troubleshoot some more by starting the car and spinning the rear up to see if it is still having the vibration? ( By doing so, in theory, wouldn't it take the tires out of the equation? )

asteeler4life
3rd-June-2010, 10:21 PM
Check your trans mounts and make sure they are secure and no bad rubber. I had this problem in my uncle's 69 camaro and i did the driveshaft balance and the alignment thing, to no end. Went under there and studied everything and it turned out the trans wasn't mounted properly. DOH

TomM
4th-June-2010, 10:32 AM
The car is still on jacks, ( and wheel chocked ), should I troubleshoot some more by starting the car and spinning the rear up to see if it is still having the vibration? ( By doing so, in theory, wouldn't it take the tires out of the equation? )

You could do that, just make sure to screw some lug nuts on your rear drums/rotors, so they don't go sailing through a wall.....:eek:

You might also check the runout on you drums/rotors too. Sometimes they can get warped and vibrate. In addition, check your axles too, it's possible one could be bent......you never know.....

T,

grega
4th-June-2010, 10:44 AM
I am sure you checked but hey you asked, if you have headers make sure you have no clearance issues.Do not jut look from top of engine look from underneath as well. I found a collector was spun hitting the subframe on my car that caused a vibration I was sure I could never fix. I tried everything.found that and went DUH! Just make sure nothing is touching even when motor is torqued.(you wil need a buddy and a good e-brake for this). Thats my advise for ya as well as all the other possible suggestions you have received.Hope it helps.

Greg

70NovaSS
4th-June-2010, 02:03 PM
I don't want to steel this thread, but rather tag along on it. :D I have a bad vibration as well, coming from the rear end of the car. I did change the 10 bolt rear, using a completely rebuilt rear end, but I am not yet sure if it's a driveline balance issue or a bushing or bearing issue. It gets progressively worse above 60MPH.

CdnL79 Registry
4th-June-2010, 02:12 PM
Running different sizes front and rear. Great idea though to see if the vibration disapears...

How old are your tires? I had a bad vibration that drove me nuts. Ended up my 13 year old tires were beginning to break down.

Bob

ovrdrive
4th-June-2010, 05:58 PM
CdnL79,

SORRY.... I forgot to mention that the tires are not brand new but about 10 months old, Kuhmo ASX. I didn't get a chance to rebalance the tires today but, 1st thing tomorrow morning..

Dan_Lebherz
5th-June-2010, 08:22 AM
When you installed your 200-4R did you put a new yoke on your DS for the new trans?

I ran the pwerglide yoke on my DS for about 2 years but finally learned it is really not the right one. The replacement yoke is maybe 1/2" longer and it inserts further into the bushing in the rear of the 2004R. Since mine was too short it had a little play in it and it wore out the rear bushing in the 2004R. I had the bushing replaced, had the driveshaft balanced and straightened and had the new yoke installed. Fixed my problem.

71nova
5th-June-2010, 11:10 AM
A problem I've ran into a few times now with a higher speed vibration is the rear yoke. Look at the u joint engagement into it and see if one of the two tangs that come off the yoke is worn more than the other. (causing a side to side movement) It doesn't take much to cause a vibration. I had this problem in my 71 nova and put another yoke on it and problem solved.

ovrdrive
5th-June-2010, 09:36 PM
71nova,

As for the 2 tangs at the other end, I took a good look at those when I spun the driveshaft 180 degrees and both are there.


Dan

another good catch. I replaced my yoke the same time I did the rear end.


Today I replaced the rear end fluid with a 50 /50 blend of Royal Purple and Lucas Oil treatment. Plus, the much needed posi fluid. The placement of the gears looks good before I refilled the pumkin. I put some white lithium grease on the gears and the wear pattern is dead center.

Then proceeded to go for a 20 minute test ride. The ride went well but, the vibration is still there but not as bad as before. The only thing that is constant on the car as it sits now is the driveshaft and the exhaust. I will look into a local place that does that and re-check all the exhaust hangars to ensure the rubber is in good condition. Plus, I had a kit full of o-rings that I put on the screws that go in the rear view mirror to see if that will work..

Simms
7th-June-2010, 06:24 AM
Alright, from what ive read nothing has given you a solution. I have experienced this before and hopefully it will help. When was the last time you replaced the hub bearings?

CDAN 66
7th-June-2010, 11:13 AM
Speed related,not to be confused with RPM ?Put the car on jack stands all 4 corners .Place the rears on the axle not to effect pinion angle ,fronts lower control arm, keep it level.Run it up to ID the range it may help. Since your tires are differant sizes you can swap them now and it won't effect the ride.Also if you have a helper let them be the test pilot and you can maybe observe drive line activity.Also if at RPM don't forget harmonic balancer.If it's RPM you can just run it up in N . Not sure of your trans if manual try other gears if RPM? NVH problems are very tough to fix keep looken. Last note be safe on the jack stand set up !!!!!!!!:yes::yes::yes:

ovrdrive
7th-June-2010, 05:36 PM
Simms,

Are you talking the front inner and outer bearings? If so, they were replaced about 2 yrs ago, if my memory is correct.


CDAN66,

Tell me about it... I was also thinking about the harmonic balancer being the culprit but, I will look into that. I will 4 point the car and maybe when I crawl under the car, I will find something. I hope..... I will take some videos and some stills of this adventure. Maybe the images will catch something I missed.

CDAN 66
7th-June-2010, 09:01 PM
"somewhere in MD"I'll be in Salisbury the end of aug.if your still in a pickle! good luck. Keep us up to date.:yes:

the FLYER
7th-June-2010, 09:13 PM
I have a vibration from the rear section of the car.


I can't actually feel it


but, the rear view mirror is shaking like crazy.


The rpm range is around 1800-2000 if that helps.



as i read the symptoms, my diagnosis is this...


it's the resonance frequency of your exhaust, climbing and changing as the RPMs increase, they come in tune with the mirror's "frequency"... causing it to vibrate.


Tesla stated (paraphrasing) that all things have their frequency and given the opportunity he could bring down a bridge. sound waves being in tune so to speak... i believe he almost caused his place of residence to come down during one of his experiments.



just a theory... (not about Tesla though, that's a fact)

ovrdrive
8th-June-2010, 09:02 PM
Exhaust......


2.5 aluminized exhaust with an x-pipe and ultra flows does sound sweet but, I will monitor on the next time out.

All the hangars have at least 1/2 thick piece of rubber between the exhaust hangar and the sheet metal. Should I put another piece of rubber between the hangar and the actual exhaust clamp?

the FLYER
8th-June-2010, 09:10 PM
the Flyer runs great and runs real strong... my mirror vibrates at whatever RPM (never bothered to look) but only for a short time.

don't know if it's your problem, just going off your description. you can't feel it but you see it. i tend to think it's maybe a sonic vibration rather than a mechanical one... we don't hear all sound waves. only way to change it it to change mufflers or whatever. i personally don't worry about it with the Flyer.

i say step on the gas and feed the beast.