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

[smokey_2020]

@OX1 you are spot on, none of the shops in Western NC are doing advanced diagnostics anymore, even indies do not want to risk anything. I wish I had the skills for rim and tire analysis. My garage is tiny, I have built all kinds of contraptions to do oil and transmission changes and frame anti-rust spraying, etc. but wheels do need decent amount of precision equipment to measure them.

Over the past 35 years I never encountered alignment issue causing the vibration but I will get it checked. Car wash touch was minor basically very sharp razor like edge/welding sliced the sidewall of the tire, it was not even a slight bump, I did not see any damage under car when I was working on the transmission oil change, I even checked the front axle oil, basically everything looks correct to me. Dealer said the same, they are not seeing any damage anywhere, but I do get that visual is not enough to measure.

 

[Saturnguy]

Brake Rotor?

Bent, or out of balance?

 

[smokey_2020]

I thought about it, but when I press the brake pedal lightly I do not sense any on it or on the steering wheel, nor vibration gets worse when brakes are applied. Hmm, anything is possible. These vibrations are nasty hard to find and solve

 

[Kira]

A few posts back, someone suggested damage caused to front end parts when the tire and wheel were damaged.

It really stinks when you have a "perfect runner" and something goes awry.
Maybe a control arm bushing or two withered a bit during the cold spell?

Also, re U-joints: Was there any squeaking when the vehicle was driven ice cold?

 

[rekit]

What about trying some balance beads if nothing else shows up.

 

[smokey_2020]

This is precisely, what happened to me, such a great ride that this Duramax Tahoe is and boom... These day and age is so hard to troubleshoot

It really stinks when you have a "perfect runner" and something goes awry.
Maybe a control arm bushing or two withered a bit during the cold spell?

 

[meep]

Hey these aren’t 22 inch wheels are they? I came across a high mileage Yukon XL - around 100k or so, and all 4 wheels “looked” round but were all out of round. There wasn’t any obvious damage to them - but I suspect they were thin for attempts and weight reduction and just couldn’t handle impacts well over time. The new owner downsized to 20” aftermarket wheels and the problem went away.

 

[Blue1920]

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.

“Out of Round Tires” from factory was my problem on 2 complete new sets (8 tires) purchased same day.

Went thru similar things pulling hair out.
All tires are not perfectly round.
Six (6) out out of my where way out of round.

My new shop checks roundness. Over .035” OOR they send them back.

 

[smokey_2020]

“Out of Round Tires” from factory was my problem on 2 complete new sets (8 tires) purchased same day.

Went thru similar things pulling hair out.
All tires are not perfectly round.
Six (6) out out of my where way out of round.

My new shop checks roundness. Over .035” OOR they send them back.

Interesting, I am feeling it has something to do with new tires but none of the shops are seeing anything including one with a Hunter RFB. My tires are 18" Michelins LTX. What is the shop that you work with @Blue1920 ? I assume it is a local indie? I tried a Chevy dealer, local tireshop with a Hunter RFB, regular highly rated tireshop in Asheville NC. None noticed roundness.

 

[rszappa1]

Interesting, I am feeling it has something to do with new tires but none of the shops are seeing anything including one with a Hunter RFB. My tires are 18" Michelins LTX. What is the shop that you work with @Blue1920 ? I assume it is a local indie? I tried a Chevy dealer, local tireshop with a Hunter RFB, regular highly rated tireshop in Asheville NC. None noticed roundness.

thats assuming they know how to use the Hunter Road Force....

 

[Blue1920]

Interesting, I am feeling it has something to do with new tires but none of the shops are seeing anything including one with a Hunter RFB. My tires are 18" Michelins LTX. What is the shop that you work with @Blue1920 ? I assume it is a local indie? I tried a Chevy dealer, local tireshop with a Hunter RFB, regular highly rated tireshop in Asheville NC. None noticed roundness.

If you can jack one tire Safety just barley off concrete so you can turn tire. Take 2” x 4” x 1’ long ish board lay it perpendicular to tire.
Side board till just touches tire. Now very slowly rotate tire. If out of round very much it will push the board away. Measure gap is the OOR”. None will be perfectly round I ever saw but ride well. My were like 1/4” plus gap. All but two (2) tires out of 8.

Measuring mount up on balance machine (not balance) with dial indicator is how my new guy checks them before going on car. Over .035” they go back.

All tires have some kind Uniformity Warranty for like before first 2/32” wear.

I guess maybe shops don’t get paid to dismount, return, remount & balance is why they don’t speak up or I can’t image they don’t know.

I had to educate myself. Wasn’t easy for me.
Six (6) new top of line Bridgestone Touring tires & all was fine.

 

[Blue1920]

If you can jack one tire Safety just barley off concrete so you can turn tire. Take 2” x 4” x 1’ long ish board lay it perpendicular to tire.
Side board till just touches tire. Now very slowly rotate tire. If out of round very much it will push the board away. Measure gap is the OOR”. None will be perfectly round I ever saw but ride well. My were like 1/4” plus gap. All but two (2) tires out of 8.

Measuring mount up on balance machine (not balance) with dial indicator is how my new guy checks them before going on car. Over .035” they go back.

All tires have some kind Uniformity Warranty for like before first 2/32” wear.

I guess maybe shops don’t get paid to dismount, return, remount & balance is why they don’t speak up or I can’t image they don’t know.

I had to educate myself. Wasn’t easy for me.
Six (6) new top of line Bridgestone Touring tires & all was fine.

Oh yea forget. I roadforce balanced etc & no help. As my mech said you can Balance a Refrigerator but it want roll good.

 

[JohnnyG]

Were you able to check for tread separation at speed?
This can be done on a regular spin balancer, but it's very hard to see. When I found that issue with a tire once, the mechanic said "it's good" but I could see the small bulge develop while spinning on the balancer.
And yes, it would balance just fine, and was round while not spinning!

 

[smokey_2020]

Drove 400+ miles today. According to two different LLMs 64-73MPH is always indicative of tire or wheel issue, ChatGPT shows the need to test for torque converter shudder as well. Gemini recommends checking driveshafts u-joints as well.
All are pretty significant service requests that Asheville GMC may or may not accommodate. This is a dealer that I never went to but they operate Hunter Elite RFB machine but as folks above said, it was always about knowing how to use it. Elite does measure runout and is all about optimizing weight use. I am already $340 into all tireshop visits and this will be another $180.
Do you guys know if dealers can put a wheelset on my truck just to rule out tires/wheels?

 

[smokey_2020]

Update: local GMC dealer was competent, the gentleman went on a ride with me and car was instrumented. Vibration is not very obvious and he did not quite feel it, as I have explained it is harmonics that I mostly feel with ears (it plugs the ears making me pop them). He rebalanced on the Hunter Elite, one of the wheels was offbalance and RF was 16 he brought all 4 to <7. Elite checks for lateral runout too, he did not see any. He saw that exhaust pipe was misaligned and he readjusted thinking droning might be causing vibrations. All in all, he was very thorough and during the test drive, he on a steep hill with low low RPM he got the TQ to shudder but no shudder during normal 65-73 MPH that he can see on the recorder.
After the fixes, the car drove intially really well but after about 30-40 mins into a drive a bit of that harmonics buffeting came back, it is less noticeable but still there.

 

[Marcozi]

Glad you finally found the culprit!

 

[smokey_2020]

I wish I could say it is resolved, it is partially reduced, but I will try one more drain and flush to see if that helps in any way. Tech told me that on 10-speed transmissions, new fluid does not solve the shudder and only TQ replacement solves but he is not seeing enough failure to justify TQ replacement, TQ needs to fail repeatedly in normal driving not only on the steep hill low RPM climb.
Ordered more AC Delco ULV fluid. I loved my 3.0 Tahoe, the best highway cruiser we even owned, but we also know we lucked out for the first 49K miles, after owning 4 Tahoes/Yukon we know we will not always be lucky, previous 3 were full of problems, it is only Duramax 3.0 that was about perfect. Now sitting reading on 2025 Armada forums if this is a good enough highway cruiser for us or not.
BTW, I think it is connected to the fluid temperature, it is when fluid is hot, this issue comes.

 

[panthermike]

I wish I could say it is resolved, it is partially reduced, but I will try one more drain and flush to see if that helps in any way. Tech told me that on 10-speed transmissions, new fluid does not solve the shudder and only TQ replacement solves but he is not seeing enough failure to justify TQ replacement, TQ needs to fail repeatedly in normal driving not only on the steep hill low RPM climb.
Ordered more AC Delco ULV fluid. I loved my 3.0 Tahoe, the best highway cruiser we even owned, but we also know we lucked out for the first 49K miles, after owning 4 Tahoes/Yukon we know we will not always be lucky, previous 3 were full of problems, it is only Duramax 3.0 that was about perfect. Now sitting reading on 2025 Armada forums if this is a good enough highway cruiser for us or not.
BTW, I think it is connected to the fluid temperature, it is when fluid is hot, this issue comes.

Perhaps it is shudder then? You may consider adding some Lubegard Platinum to the drain/fill. 1oz/qt or even less than that could help.

On the 2025 Armada, the consensus seems good on them. Engineered and built in Japan. @GenSan may be able to provide input there.

 

[GenSan]

Perhaps it is shudder then? You may consider adding some Lubegard Platinum to the drain/fill. 1oz/qt or even less than that could help.

On the 2025 Armada, the consensus seems good on them. Engineered and built in Japan. @GenSan may be able to provide input there.

Never had a Tahoe but had a 95 Blazer . Coming from a 2002 Sequoia, 2012 Lexus GX460, and 2018 LX570 this 2025 Armada Pro-4x is a winner (so far 11,500+ miles). I have high expectations for it so I'll pass final judgement when I get pass 100k, and 200k.

 

[smokey_2020]

Perhaps it is shudder then? You may consider adding some Lubegard Platinum to the drain/fill. 1oz/qt or even less than that could help.

On the 2025 Armada, the consensus seems good on them. Engineered and built in Japan. @GenSan may be able to provide input there.

Not likely that it is tires/wheels. Because vibration is more harmonics than shaking, he was in a car and I felt it (with my ears) he on the other hand did not, neither does my wife I know, I know, perhaps I need to go to the doctor instead but I do know my car well. Harmonics is there, but finding it is next to impossible, until it rattles your teeth out.