Vibration, 07 9-7x 5.3 with AWD

Sid Coleman

Original poster
Member
Nov 9, 2019
20
Maryland
OK, now that I've got the new UCA reinstalled properly and Just Tires redid the alignment that came out perfect-thanks again all!, I'm back to why I had the UCA replaced. I'm getting a vibration above 70, but the odd thing is that it isn't all the time. And I can't tell if it's in just the wheel or feeling it in the seat as well. Had 2 different mechanics inspect the suspension for any bad bushings or parts-nothing now present that they could find. The original Michelin's that I bought it with were replaced by Goodyear Assurance Weatherready and were balanced when installed. Where should I start looking for the problem?
 

TollKeeper

Supporting Donor
Member
Dec 3, 2011
8,199
Brighton, CO
I am having the same problem with my XUV V8..

I have replaced the entire front suspension, and tires, brakes, rotors.. (all needed to be done anyways)

I am thinking it might be a U-Joint, but they all feel fine. Could also be a CV axle. But I hate throwing parts at it, not knowing for sure it will cure it.

Does yours start at about 72mph, and then go away around 80?
 

Mathoran

Member
May 3, 2012
54
I had a similar vibration a while ago and It was a u-joint. Had both replaced and driveshaft balanced. Vibration gone. My rear view mirror would vibrate to where everything was blurry. Guy showed me the old u-joint had a spot where it would kind of stick when you would spin it. Not sure how you can test them without removing them. Had it done at a driveline shop. Cost somewhere north of 200$ for everything.
 

Sid Coleman

Original poster
Member
Nov 9, 2019
20
Maryland
I am having the same problem with my XUV V8..

I have replaced the entire front suspension, and tires, brakes, rotors.. (all needed to be done anyways)

I am thinking it might be a U-Joint, but they all feel fine. Could also be a CV axle. But I hate throwing parts at it, not knowing for sure it will cure it.

Does yours start at about 72mph, and then go away around 80?
Mine starts around 70 and just seems to get worse the faster I go, only had it up to about 85.
 
I had a similar vibration a while ago and It was a u-joint. Had both replaced and driveshaft balanced. Vibration gone. My rear view mirror would vibrate to where everything was blurry. Guy showed me the old u-joint had a spot where it would kind of stick when you would spin it. Not sure how you can test them without removing them. Had it done at a driveline shop. Cost somewhere north of 200$ for everything.
I could have written that. Had the same issue, with one more complication.

The original driveshaft went to the driveshaft shop locally, the rear U-joint was completely wiped-out. However, the shaft was also bent. They claimed to get "most" of the bend corrected, and replaced both U-joints (although there wasn't anything wrong with the front joint.)

Before, noticeable vibration from ~68 mph, worst at 73 mph, gone by 80 mph.
After, dead-smooth at all speeds; even fixed a minor vibration I had starting at 25mph that I never noticed until it wasn't there any more. I had assumed it was rough road shake.

This lasted about two years. Vibration came back exactly like before--worst at 72--73 mph.

Both U-joints were still good. I grabbed a different driveshaft, replaced the rear U-joint in it, and fixed the vibration again. Same story--cured a lower-speed vibration I didn't know was there until it wasn't there any more. Apparently, the original driveshaft bend got worse again.

If this ever comes back, I'm going to have a Trailblazer EXT driveshaft shortened to fit my short-wheelbase Trailblazer--the EXT shaft is much larger in diameter.
 

Sid Coleman

Original poster
Member
Nov 9, 2019
20
Maryland
I could have written that. Had the same issue, with one more complication.

The original driveshaft went to the driveshaft shop locally, the rear U-joint was completely wiped-out. However, the shaft was also bent. They claimed to get "most" of the bend corrected, and replaced both U-joints (although there wasn't anything wrong with the front joint.)

Before, noticeable vibration from ~68 mph, worst at 73 mph, gone by 80 mph.
After, dead-smooth at all speeds; even fixed a minor vibration I had starting at 25mph that I never noticed until it wasn't there any more. I had assumed it was rough road shake.

This lasted about two years. Vibration came back exactly like before--worst at 72--73 mph.

Both U-joints were still good. I grabbed a different driveshaft, replaced the rear U-joint in it, and fixed the vibration again. Same story--cured a lower-speed vibration I didn't know was there until it wasn't there any more. Apparently, the original driveshaft bend got worse again.

If this ever comes back, I'm going to have a Trailblazer EXT driveshaft shortened to fit my short-wheelbase Trailblazer--the EXT shaft is much larger in diameter.
Just made the connection-assume you are the same Schurkey from Team Chevelle! Thanks for the feedback, and nice to see you online again.
 
Yeah, that's me.

I have heard about--but never actually met--other "Schurkeys". We seem to be rare. Unusual. Odd.

I've been online, but not much activity on Chevelle Tech. I stop by now and then, more lurking than posting. One too many forum "upgrades" for me.

For that matter, I'm not on this forum much, either.
 

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