mb.gov

My 2012 Silverado LTZ 1500 4x4 clunks, and more often slams when downshifting and upshifting under NORMAL driving conditions. Additionally, it easily sways forward and back when in PARK. This truck has a serious drivetrain defect. GM is NOT going to correct it.


The dealership(s) scoffed at the demonstrations of the defect, giving the GM party-line, "the vehicle is operating as designed."


After many, MANY months of patiently doing the right thing by GM, giving its service departments several attempts to diagnose and correct the drivetrain defect, and patiently and politely discussing the matter with GM customer service representatives, GM flippantly proclaims, "the vehicle is operating as designed."


During my experience, GM's customer service representatives and at least one GM engineer resorted to dishonesty about its investigation of my complaint during an extended test drive. When its dishonesty was revealed, GM responded with nothing. After all, its party-line is, "the vehicle is operating as designed." GM customer service has NO concern about its dishonesty.


It's a very sad state at GM. What's worse? I purchased a defective Chevrolet truck, soon exceeding its 36,000 warranty, and GM customer service doesn't care. I'm left to take chances that it doesn't have a catastrophic failure, resulting in injury or worse! The BBB is not going challenge GM. A lawsuit is a extreme waste of time and money.


Buyer beware!

ristpin

I keep reading about the clunk issue. Has anyone tried the GM lube I mentioned in a previous post?

mb.gov

Ristpin, I read the previous posting about a special lubricant, and within weeks I took my 1012 Silverado LTZ 4x4 in to the Chevrolet Service Department at the Austin, TX dealership where I bought it, and per my request, its mechanic reportedly applied the GM lubricant your previous post suggested to the drivetrain component(s). My service summary is out in my truck so I don't recall which specific component(s), other that the YOLK.


There was NO halleluiah moment after the lube application. My truck's slam/clunk/jolt was still there. The service manager warned that lube application was likely not going to correct the drivetrain problem that has been labeled "clunk".


I appreciate your suggestion. Unfortunately a lubricant application is NOT the answer. I'm fairly confident the GM experts wish that it were the solution.


I'm positive GM experts will not exchange any major drivetrain components to correct the defect that produces "clunk, slam, jar, jolt, excessive lag, hit" or any other name customers give it. I'm confident GM knows what causes it. I'm confident that GM has promulgated an arbitrary tolerance testing protocol to its staff such that even severe incidents are NOTHING more than, "the vehicle is operating as designed."

ristpin

All I know is it worked for me. My "clunk" was coming just as I would stop for a light, or stop sign as the shifting weight would slightly move the drive shaft forward. I guess I question if they used the right stuff. Good luck, I hope you get the problem corrected.

mb.gov

2014 Silverado 1500 LTZ 4x4 - CLUNK Driveline Defect Document ID# 1430424
2003 Chevrolet Chevy Suburban - 4WD
--------------------------------------------------------------------------------
Information on 2-3 Upshift or 3-2 Downshift Clunk Noise #01-07-30-042B - (Jan 16, 2004)
Information on 2-3 Upshift or 3-2 Downshift Clunk Noise
2004 and Prior Light Duty Trucks
2003-2004 HUMMER H2
with 4L60E or 4L65E Automatic Transmission (RPOs M30, M32)

This bulletin is being revised to add the 2004 model year. Please discard Corporate Bulletin Number 01-07-30-042A (Section 07 - Transmission/Transaxle).

Some vehicles may exhibit a clunk noise that can be heard on a 2-3 upshift or a 3-2 downshift.
During a 2-3 upshift, the 2-4 band is released and the 3-4 clutch is applied. The timing of this shift can cause a momentary torque reversal of the output shaft that results in a clunk noise. This same torque reversal can also occur on a 3-2 downshift when the 3-4 clutch is released and the 2-4 band applied. This condition may be worse on a 4-wheel drive vehicle due to the additional tolerances in the transfer case.
This is a normal condition. No repairs should be attempted.
--------------------------------------------------------------------------------