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GM Tech (Cam)
GM Tech (Cam), Chevy Technician
Category: Chevy
Satisfied Customers: 15181
Experience:  GM Grand Master Technician 2007. 14 years experience.
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, A driveline vibration in a 2001 Chevrolet Tahoe, 4x4

Customer Question

JA: Thanks. Can you give me any more details about your issue?
Customer: A driveline vibration in a 2001 Chevrolet Tahoe, 4x4 it seems throttle position AND speed dependant
JA: OK got it. Last thing — Chevy Mechanics generally expect a deposit of about $18 to help with your type of question (you only pay if satisfied). Now I'm going to take you to a page to place a secure deposit with JustAnswer. Don't worry, this chat is saved. After that, we will finish helping you.
Submitted: 1 year ago.
Category: Chevy
Customer: replied 1 year ago.
Are you there?
Customer: replied 1 year ago.
Vibration starts at 40-ish mph, continues to 55-ish, and then comes back at 68-ish and then just gets worse the faster i go.
it does not matter what gear its in, the problem persists,
the tires and wheels are new, and the problem was there before wheels and tires were replaced,
the entire rear axle has been replaced, the problem was there before and after,
the vehicle is stock height
tires are stock size
gear ratio was 3.73 and the problem existed badly, then switched the whole axle to one with 4.10 and the problem went away for a while, then came back, then i had 4.88 gears installed, the problem persisted.
i had a new rear driveline built, and the problem went away, but has come back with a vengeance.
shocks are all Bilstein and in good shape,
exhaust is stock,
transmission mount has been recently replaced
transfer-case is not very old, and the tail bushing seems tight
i (we) cannot find anything loose under the vehicle
Customer: replied 1 year ago.
i at one point added a 3/16" shim under the trans mount, raising the transfer case to create more angle, and the vibration was worse.
Expert:  Reggie Whiddon replied 1 year ago.

Have you put the vehicle on a hoist or stands and removed tires reinstall lugnuts and ran up to speed

Customer: replied 1 year ago.
No, I have not
Customer: replied 1 year ago.
what would i be looking for?
Expert:  Reggie Whiddon replied 1 year ago.

By doing that you eliminate the tires and rims from the equation if your vibration is gone it's in tires

Expert:  Reggie Whiddon replied 1 year ago.

If it's still there and unchanged we will then look elsewhere, what are your alignment specs I have seen grossly incorrect caster settings cause this

Expert:  Reggie Whiddon replied 1 year ago.

And you would be surprised 9 out of 10 alignment techs have no idea other than set the toe

Customer: replied 1 year ago.
Front wheel caster causing a vibration?
Expert:  Reggie Whiddon replied 1 year ago.

Yes sir sounds crazy dont it? A man who was much higher up the chain than me pointed it out to me, now this vehicle did have slightly oversized tires. Have you had the alignment checked so thrust angle and setback and sai can be checked

Customer: replied 1 year ago.
The vehicle has been aligned to factory spec 3 or 4 times in the last couple of years
Expert:  Reggie Whiddon replied 1 year ago.

Okay well what do you think about running it without tires will you try that? with a problem like this i have found it best not to take nothing for granted. That is my first step

Customer: replied 1 year ago.
I'll do exactly that.
Customer: replied 1 year ago.
I have a suspicion it is a pinion angle problem, as it keeps coming back after every attempt.
I think it is trashing U-joints because of pinion angle
Customer: replied 1 year ago.
I think adjustable upper control arms are the eventual answer
Customer: replied 1 year ago.
Spohn makes them
Expert:  Reggie Whiddon replied 1 year ago.

Okay u want the drive shaft to have between 1 and half to 4 degrees

Expert:  Reggie Whiddon replied 1 year ago.

Do you know how to check

Expert:  Reggie Whiddon replied 1 year ago.

The problem I have with thst is when thst is the problem it is constant

Expert:  Reggie Whiddon replied 1 year ago.

Tell me about this vehicle have therr been any suspension modifications or powertrain changes

Customer: replied 1 year ago.
Read above.
Expert:  Reggie Whiddon replied 1 year ago.

Okay I see stock height and stock tire size, only modification was your rear end. Did you modify the programming to that gear, does your speedometer work properly? One question you mention you had a new driveshaft built was that shaft balanced? You say the problem is back but worse possibly one of the weights has come off. Have you run it without the tires yet?

Customer: replied 1 year ago.
I have not yet. It snowed another foot.
Expert:  Reggie Whiddon replied 1 year ago.

Another foot! A foot of snow would shut alabama down, well I understand just checking with you. I'm anxious to see whst your problem is