Vibration (like buffeting) 68-73MPH new tires, 3 different shops checked

[smokey_mountain]

Hope the wisdom of the crowd will help me troubleshoot further. I am stumped. This truck was one of the smoothest riding highway cruisers, zero vibrations for 49,000 miles of any kind up until recent episode.

23 Tahoe Duramax 3.0 4x4 LS with 10-speed AT with 49,500 miles.
Carwash damaged/cut my front tire and scratched the wheel. I had purchased a new Chevrolet OEM takeoff rim on eBay and 4 new Michelin Primacy LTX tires.

After tire and wheel install, I have noticed a vibration strictly during 68-73MPH (that is felt as buffeting like rear windows are open). I had taken the car back to the install shop, they roadforce it on the Hunter machine, one tire was pretty close to be out of range, Tirerack replaced the tire. Installed and re-balanced at another tireshop, they confirmed that all tires were within spec, however vibrations were still there. Took it to the dealer, paid for the re-balance and rotation.

Wanted to do a rotation to see if vibration will move from back to the the steering wheel on the front, but - same vibration/buffeting. Chevy dealer says it is not very likely the tires or rims are the problem (dealer himself does not of course reproduce the problem, because they cannot testdrive at 68-73MPH).

Additional thoughts:
-very narrow range strictly 68-73MPH
-rotation does not seem to change anything
-3 different tireshops does not seem to think the tires are the problem, but not sure if I need high quality $#4 who can validate if rims are not out of true or something with the wheel(s)
-maybe I am dreaming (not certain) but I am sensing this buffeting more when coasting (foot off the accelerator)
-lastly, if I am going through a corner in this speed (68-73MPH), I also feel even more

My hypothesis:
1) torque converter shudder, I am planning to do pan drop/drain/filter/fill on A/T.
2) takeoff rim causing the problem but balancing machines are not detecting rim problems (this is farfetched in my mind but I am not an expert on balancers if they can detect out of true or general rim issues)

Appreciate the thoughts.

 

[tom3]

Drop the transmission down a gear or two in low range mode and try at that speed. Adjust tire pressures down 4 or 5 lbs. Put rear seats down. Have someone follow you down the road at that speed and look at the tires and wheels for any run out or anything else not normal. Put the Tahoe up on a hoist and inspect the underbody really close, look for other damage from the carwash screwup. Look for scratch or dent in driveshaft.

 

[mikez71]

Since you say it seems to be more pronounced coasting and turning...
See if it's worse turning one direction vs the other.

Maybe a wheel bearing or wheel alignment took a hit at the carwash too?

 

[OR VietVet]

So, finally, 2/3 way thru, you said the vibes were coming from the rear. How did you determine that the vibes were from the rear?

 

[smokey_mountain]

So, finally, 2/3 way thru, you said the vibes were coming from the rear. How did you determine that the vibes were from the rear?

Thank you for pointing out this nuance. Initially, I deduced that since no vibration felt on the steering wheel or pedals and that vibrations are almost heard/felt by ears exactly like open rear window buffeting, I felt that it must be from the rear. However, if dealer indeed rotated ( I assume they truly did), and vibration still being there, I assumed it cannot be tires/rims. BTW, when carswash cut the right front tire it was not a hard hit or anything like, just a slice by a poor welding job on the carwash rails.

 

[OR VietVet]

I would suspect the wheel you bought. Something "within tolerance" does not mean it is correct.

 

[slupie]

Move the replacement wheel to different postion, see what happens, does the noise follow the wheel or stays at the same positon. Remove the replacement wheel and try it with a sapre wheel, what happens then. Check the suspension see if there is anything wrong, loose ball joints, bad wheel bearing, etc. It may be coincidence with the timing it happened but could be anything. Try to eliinate one thing at a time.

 

[PPK_]

Check your rear half shafts.. my left was leaking grease.. changed it.. vibration now gone… 10k miles too.

 

[2024 White Tahoe]

I would suspect the wheel you bought. Something "within tolerance" does not mean it is correct.

And why did you buy a rim from EBay, instead of new from a Chevrolet dealer (since the carwash would be paying for it)?

 

[ReaperHWK]

Throw the full size spare on the suspect wheel corner.

 

[tsuintx]

And why did you buy a rim from EBay, instead of new from a Chevrolet dealer (since the carwash would be paying for it)?

Good question. Maybe the carwash or their insurance carrier sent OP a check for the damages and OP decided to find cheaper alternatives and pocket the difference.

 

[tom3]

Road Force balance should remove any concern about wheels and tires. This is one weird situation.

 

[Tazio]

Have you tried running it on a lift with all 4 wheels off the ground at the critical speeds to see if it happens then? Also check for a bent driveshaft or a missing balance weight on the shaft.

 

[petethepug]

If you put the truck in neutral and still No Longer detect the vibration at those speeds , it’s not the wheels.

 

[smokey_mountain]

Good question. Maybe the carwash or their insurance carrier sent OP a check for the damages and OP decided to find cheaper alternatives and pocket the difference.

Carwash told me - "sue me, you are not getting a dime from us, too bad so sad." Of course, I could have gone to Small Claims but those are backed up for months. In retrospect, I should have paid $650 for a new rim from a dealer. However, 4 tireshops including with Hunter Elite RFB found zero issues with wheels or tires.

 

[smokey_mountain]

If you put the truck in neutral and still No Longer detect the vibration at those speeds , it’s not the wheels.

Yes, thank you for this valuable tip, I will try that. Competent GMC tech instrumented and rode with me , found that on a very steep incline in very low speed and low RPMs TQ shudders but in normal highway driving in the 65-73MPH speed band no shuddering that he can record on the tester. He still RFBed the tires on the Hunter Elite but to no avail. He could not sense the harmonics because they according to him they are not "felt" but rather I sense them with my ears they actually get plugged up and I need to pop them by yawning (I know hard to believe but it is what it is).
Tech said that to do proper harmonics testing with Pico, GM warranty would not authorize it, so it is out of pocket and not cheap - $430 for this test. I am already $520 into tests and constant rebalances. Will do second drain and fill this weekend and see if it helps if not, as you guys said, I am not likely to find the root of it.

 

[LsHart]

New rim needs to be checked without the tire on it. Then what is the DOT date on the replacement tire?

 

[smokey_mountain]

New rim needs to be checked without the tire on it. Then what is the DOT date on the replacement tire?

before putting new rim, local tireshop did spin the rim to check it on the Hunter machine, did not see anything wrong with it. Tires from Tirerack were 03 2024.

 

[LsHart]

That should balance out.

 

[LsHart]

before putting new rim, local tireshop did spin the rim to check it on the Hunter machine, did not see anything wrong with it. Tires from Tirerack were 03 2024.

Sounds to me that there is a different issue the just happened to co insides with that car wash mishap.