02 TB Has Vibration at 65 - 70 MPH

[compudude]

I've got an 02 TB with 43K miles that exhibits a high frequency vibration, (noticed in the floor boards, gas pedal, and especially in the shaking rear view mirror) only in between 65 and 70 MPH. Any faster or slower and everything is smooth again. At first I thought it was a tire, but I just replaced all four (for normal wear) with high end Michellins and vibration problem persists.

I do see threads speaking of the rear coil springs being the culprit, and wonder if my GMPP Major Guard extended warranty would cover something like this. Has anyone had any luck trying to dampen the vibration by stiffening the rear coil springs using some sort of hard rubber spacers?

Thanks

[phewop118]

Check your wheel alignment. It can cause vibration that is isolated at certain speeds.

[maxwedge]

The spring cure is for a drumming sensation at 55-62, not your problem here. I would have a close look at driveshaft balance or a possible dent in the driveshaft, possible u'joint. The frequency shudder corrected ( somewhat) by the springs would have there from day one.

[tmleadr03]

Originally Posted by compudude

I've got an 02 TB with 43K miles that exhibits a high frequency vibration, (noticed in the floor boards, gas pedal, and especially in the shaking rear view mirror) only in between 65 and 70 MPH. Any faster or slower and everything is smooth again. At first I thought it was a tire, but I just replaced all four (for normal wear) with high end Michellins and vibration problem persists.

I do see threads speaking of the rear coil springs being the culprit, and wonder if my GMPP Major Guard extended warranty would cover something like this. Has anyone had any luck trying to dampen the vibration by stiffening the rear coil springs using some sort of hard rubber spacers?

Thanks

If your feeling it from the front end (ie through the gas pedal) it probably has something to do with the front of the vehicle. I would have the steering and suspension checked out up front. Is the vibration equal on both sides of the vehicle? I still really like it being a wheel/tire combo. If you can find a place with a road force balancer they can easily check the run out on the rim and let you know if your wheel is bent. Many dealerships would have that these days.

[compudude]

OK, the problem is still there. Here's some more info:

-Seems more pronounced on days when temperature is below 40 degrees.
-Very noticable high frequency vibration felt in gas pedal/floor boards, and seen in rear view mirror shake, between 60 and 75 MPH.
-I hear a rumbling noise from under the front when going 20MPH or slower (even in neutral).
-High speed vibration is there regardless of whether vehicle is in gear or neutral. Tested by coasting (in neutral) down a steep hill on highway at 65 MPH.
-Does not seem related to engine RPMs.
-Vibration started while still on OEM tires, and continues with four new Michellins.

This is really annoying, but beyond that I wonder if there's something about to fail that would not be fun to deal with at highway speeds..

Any thoughts would be greatly appreciated.

Thanks.

[maxwedge]

Look for a kink in the driveshaft first, then suspect a rpoblem with a joint or out of balance shaft, run it on a lift see if you feel the vibe, also look to see if the shaft is running true at the same time.

[compudude]

Thanks for the imput Maxwedge.

I've still got 30K of GMPP left on this thing, so I will try the dealer first. My gut feeling is U-joints. Outside of something hitting/damaging the drive shaft (which I don't think has happened), would it be probable that the drive shaft would go out of round, or out of balance all on its own?

Thanks again!

[maxwedge]

There were some issues with driveshaft build quality, but that would have shown up from day one, even a slight kink can cause this, u joints usually don't show up at low mileage. There was also a problem with a harmonic type vibration at about 58-62, that was corrected with different rear springs, but that was rpm sensitive, 1700-1900rpms. This does not sound like this based on speed and your description, let the dealer have at it.

[tmleadr03]

Originally Posted by compudude

Thanks for the imput Maxwedge.

I've still got 30K of GMPP left on this thing, so I will try the dealer first. My gut feeling is U-joints. Outside of something hitting/damaging the drive shaft (which I don't think has happened), would it be probable that the drive shaft would go out of round, or out of balance all on its own?

Thanks again!

My gut feeling if you are having a growling sound at low speeds is CV joints.

[rodeo02]

Only at 65-70mph & no noises or perfmormance concerns associated with it? I'd still suspect a tire/wheel issue. A bent wheel, a wheel that wont center properly or just a more precise wheel balancing is needed. Road-force wheel balancing is the most precise.

Joel

[tmleadr03]

Originally Posted by rodeo02

Only at 65-70mph & no noises or perfmormance concerns associated with it? I'd still suspect a tire/wheel issue. A bent wheel, a wheel that wont center properly or just a more precise wheel balancing is needed. Road-force wheel balancing is the most precise.

Joel

He says he is hearing a growling noise under 20 mph, thats CV joints most likely. But more then anything else he needs a tech to look at it, not try to diagnoise it over the internet. Noise diagnostics on the ASEs are hard enough, over the internet is even more fun.

[compudude]

Thanks to all for the input. Much appreciated!

One thing's for sure. Ambient temperature comes into play, as today it was almost 60 degrees and my highway ride home was nice and smooth. I made sure to keep it in the problematic speed range, and voila no problems. This is the second time since last fall (when the problem first appeared) that its been warm, and that's when the car rides normal.

Any way, I've made a service apppointment with the dealer. I plan to have the vehicle's 4WD system serviced (lubricant/fluid change on both differentials and transfer case). I will also have them inspect the drive shaft, U joints and CV joints. I'm at 49,000 miles so I assume it would be a good time to service the 4WD system anyway. I'm getting a sinking feeling that this problem is about to disappear until next fall.

I'll keep everyone posted....

[rodeo02]

Originally Posted by tmleadr03

He says he is hearing a growling noise under 20 mph, thats CV joints most likely... .

I wouldn't rule anything out at this point, but a CV joint/half shaft vibrating at speed on a straight away on a stock truck, would likely be popping and clicking like crazy on turns. GM would win the all-time genuine junk award for loosing CV joints @ ~4yrs/50Kmi.

Joel

[compudude]

Well, dealer could not duplicate the vibration. I knew that would be the case as it has lessened dramatically as the weather has warmed up. Now, even I bearly feel it in the floor boards, and the rear view mirror is nice and steady.

I'll have to wait for winter (or for what ever is going to let loose.) Good thing for GMPP... 2 years and 30,000 miles left on it.

Thanks to all for your input. If I come across the fix, I'll be sue to post back.

[Robert1010]

I have a 2004 TB LT With the same problems. Cold temps make things much worse. The rear vibration (spring replacement) will vary with mph and rpm with tire size and rear ratio. While accelerating during the 60+mph vibration lightly press the brake pedal. This will disengage the TCC (torque convertor clutch) the vibration will stop. The new springs will help, they will not totally cure the vibration.

The front vibration feels like running over a rumble strip. I can not reproduce this vibration enough to check anything.

Please let us know if you ever find a cure.
Thanks