2015 Silverado 5.3 Slip yoke clunk ?

[zert100]

Got my truck back from the 2nd attempt this last saturday, the clunking and shuddering was not repaired.

requested a buy back from the dealer.

 

next ill file with BBB if they give me the run around.

 

Got mine back today with no resolution. It seems that GMC's idea of professional grade is a sloppy drivetrain.

 

CentralCAz71...I sent you a PM

[CentralCAz71]

im going back this saturday 31st to speak with some big wig at the dealer, they want to drive mine and another 4wd back to back to compare and determine if its a 4wd characteristic or if its something to unique to mine ( like it makes a difference? ) If they try to say that it is normal for all 4wds im going to stop dealing with the damn dealer and file with the BBB see how that goes.

Got mine back today with no resolution. It seems that GMC's idea of professional grade is a sloppy drivetrain.

 

CentralCAz71...I sent you a PM

[Nathan79]

The Chevy clunk has been common for many years.

[zert100]

The Chevy clunk has been common for many years.

Not all clunks are the same. In years past a lot of the trucks suffered from the slip yoke issue. That does not appear to be the case with the late model trucks. Some are seeing problems with excess lash in the rear diff. others in the Trans and T-cases. Either way it is something that GM should be addressing.

[Nathan79]

Not all clunks are the same. In years past a lot of the trucks suffered from the slip yoke issue. That does not appear to be the case with the late model trucks. Some are seeing problems with excess lash in the rear diff. others in the Trans and T-cases. Either way it is something that GM should be addressing.

 

I don't know what is causing it. However, the descriptions sound exactly like the clunks my 2012 did and were very common in previous generations. Also, adding a Diablo tuner reduced the clunking dramatically. I'm going to assume that this is not what is being experienced (this from way back in 2003):

 

Bulletin No.: 99-04-20-002B

Date: August 21, 2003

 

Subject:

Drive line Clunk

 

Models:

2004 and Prior Light Duty Truck Models

2003-2004 HUMMER H2

 

Important: The condition described in this bulletin should not be confused with Drive line Stop Clunk, described in Corporate Bulletin Number 964101R (Chevrolet 92-265-7A, GMC Truck 91-4A-77, Oldsmobile 47-71-20A, GM of Canada 934A-100) or Bump/Clunk Upon Acceleration, described in Corporate Bulletin Number 99-04-21-004A.

 

Some owners of light duty trucks equipped with automatic transmissions may comment that the vehicle exhibits a clunk noise when shifting between Park and Drive, Park and Reverse, or Drive and Reverse. Similarly, owners of vehicles equipped with automatic or manual transmissions may comment that the vehicle exhibits a clunk noise while driving when the accelerator is quickly depressed and then released.

 

Whenever there are two or more gears interacting with one another, there must be a certain amount of clearance between those gears in order for the gears to operate properly. This clearance or free play (also known as lash) can translate into a clunk noise whenever the gear is loaded and unloaded quickly, or whenever the direction of rotation is reversed. The more gears you have in a system, the more free play the total system will have.

 

The clunk noise that owners sometimes hear may be the result of a buildup of free play (lash) between the components in the Drive line.

 

For example, the potential for a Drive line clunk would be greater in a 4-wheel drive or all-wheel drive vehicle than a 2-wheel drive vehicle. This is because in addition to the free play from the rear axle gears, the universal joints, and the transmission (common to both vehicles), the 4-wheel drive transfer case gears (and their associated clearances) add additional free play to the Drive line.

 

In service, dealers are discouraged from attempting to repair Drive line clunk conditions for the following reasons:

 

Comments of Drive line clunk are almost never the result of one individual component with excessive lash, but rather the result of the added affect of free play (or lash) present in all of the Drive line components.

Because all of the components in the Drive line have a certain amount of lash by design, changing Drive line components may not result in a satisfactory lash reduction.

 

While some owners may find the clunk noise objectionable, this will not adversely affect durability or performance.

[Ron.s]

I don't know what is causing it. However, the descriptions sound exactly like the clunks my 2012 did and were very common in previous generations. Also, adding a Diablo tuner reduced the clunking dramatically. I'm going to assume that this is not what is being experienced (this from way back in 2003):

 

Bulletin No.: 99-04-20-002B[/size]Date: August 21, 2003[/size]Subject:[/size]Drive line Clunk[/size]Models:[/size]2004 and Prior Light Duty Truck Models[/size]2003-2004 HUMMER H2[/size]Important: The condition described in this bulletin should not be confused with Drive line Stop Clunk, described in [/size]Corporate[/size] Bulletin Number 964101R (Chevrolet 92-265-7A, GMC Truck 91-4A-77, Oldsmobile 47-71-20A, GM of Canada 934A-100) or Bump/Clunk Upon Acceleration, described in Corporate Bulletin Number 99-04-21-004A.[/size]Some owners of light duty trucks equipped with automatic transmissions may comment that the [/size]vehicle[/size] exhibits a clunk noise when shifting between Park and Drive, Park and Reverse, or Drive and Reverse. Similarly, owners of vehicles equipped with automatic or manual transmissions may comment that the vehicle exhibits a clunk noise while driving when the accelerator is quickly depressed and then released.[/size]Whenever there are two or more gears interacting with one another, there must be a certain amount of clearance between those gears in order for the gears to operate properly. This clearance or free play (also known as lash) can translate into a clunk noise whenever the gear is loaded and unloaded quickly, or whenever the direction of rotation is reversed. The more gears you have in a [/size]system[/size], the more free play the total system will have.[/size]The clunk noise that owners sometimes hear may be the result of a buildup of free play (lash) between the components in the Drive line.[/size]For example, the potential for a Drive line clunk would be greater in a [/size]4-wheel drive[/size] or all-wheel drive vehicle than a 2-wheel drive vehicle. This is because in addition to the free play from the rear axle gears, the universal joints, and the transmission (common to both vehicles), the 4-wheel drive transfer case gears (and their associated clearances) add additional free play to the Drive line.[/size]In service, dealers are discouraged from attempting to repair Drive line clunk conditions for the following reasons:[/size]Comments of Drive line clunk are almost never the result of one individual component with excessive lash, but rather the result of the added affect of free play (or lash) present in all of the Drive line components.[/size]Because all of the components in the Drive line have a certain amount of lash by design, changing Drive line components may not result in a satisfactory lash reduction.[/size]While some owners may find the clunk noise objectionable, this will not adversely affect durability or performance.[/size]

IMO, this is GM's BS way of telling the dealer not to spend money on diagnostics. Every year they update the mehicle model years covered and issue a new bulletin. I was given one including model year 2014 and the exact same bulletin adding 15's the following year. Apparently enough people accept this and move on versus those like me that know better. This was one factor in my getting a buy back.

[zert100]

IMO, this is GM's BS way of telling the dealer not to spend money on diagnostics. Every year they update the mehicle model years covered and issue a new bulletin. I was given one including model year 2014 and the exact same bulletin adding 15's the following year. Apparently enough people accept this and move on versus those like me that know better. This was one factor in my getting a buy back.[/quote

 

Yes, I agree that TSB is in place to cover a lot of complaints and in some cases I'm sure its valid. The thing that bothers me about it is I think GM and some dealers sometimes overuse this TSB to get out of fixing a legitimate issue. Yes, a certain amount of driveline lash, slop, whatever you want to call it is to be expected, especially in a 4wd vehicle. Where I start to have a problem with it is when they use a blanket stance to cover any truck that has excess lash in their drive system. Handling cases like that is not acceptable for these very expensive vehicles.

[pm26]

Maybe the government should introduce another round of the "cash for clunkers" program?

[CentralCAz71]

I agree, this clunk is not acceptable. When i had only 500 miles on it , the clunk was there just not quite loud enough for me to care about it. I guess if it would've stayed that way, i would be able to live with it. I don't expect this truck to be silent like a CVT sedan vehicle. However, it has gotten much louder and the bangs are felt through the cabin by all my passengers. I drove with some manager guy at my local dealer again this weekend and he tried to make up all this bull crap reasons why its normal. He even had me drive a another identical truck with 10miles on it.

All i took from it is, the truck with 11miles on it had the clunk too just more toned down and quieter like mine use to be. Had my truck been clunking the way it is now on the day i was buying, i would have walked away. Selling a product that runs smooth at 10miles, and clunks and jerks soon as it hits 2800 miles is unacceptable !!! specially when it costs upwards of $40k.

 

The manager wants me to bring it in again for a 3rd attempt, with no promise or inclination to working towards a buyback which is what i requested.

 

 

 

 

IMO, this is GM's BS way of telling the dealer not to spend money on diagnostics. Every year they update the mehicle model years covered and issue a new bulletin. I was given one including model year 2014 and the exact same bulletin adding 15's the following year. Apparently enough people accept this and move on versus those like me that know better. This was one factor in my getting a buy back.

[CentralCAz71]

3rd attempt to repair this clunk was finished yesterday.

 

I filed with the BBB last week with 2 attempts on file ( uploaded the 3rd repair doc to bbb this morning) , the manufacturer responded with a request for BBB to deny my buy back claim.

 

I spoke to a GM rep and she blatantly lied to me in regards to California Lemon Law. Thats when I knew I had to contact a Lemon Law Attorney. My case is now being reviewed by an attorney. Sad it had to go down this way.

[joeisalsocool]

I've been following these noise threads since I got my truck 2 months ago.

I recently came upon this thread:

http://www.gm-trucks.com/forums/topic/172777-clunkthud-while-acceleratingslowing-down/page-9

Found that the 14's may have a TSB for tightening the nuts on the leaf spring U bolts.

The 15's have no such fix. So just for the hell of it, I climbed under the truck with my trusty torque wrench, and started at 20 ft/lbs... yes, 20. And wouldn't you know, every damn bolt turned 1/8 to 1/4 turn before it clicked! Torque spec for these bolts is 78 ft/lbs! I upped mine to 50 just to test.

The difference? Night and day. Shifting now feels like my '07 F150, tight and smooth.

Half second gear changes, clunk while coasting down hill and applying gas, clunk while coasting up hill and switching from 2nd to 1st, and shuttering from 3rd down to 1st.... all gone!

I finally have the truck I signed for!

 

Just thought I would pass this along to anyone interested. Free fixes are the best.

[14silverado4.3]

I've been following these noise threads since I got my truck 2 months ago.

I recently came upon this thread:

http://www.gm-trucks.com/forums/topic/172777-clunkthud-while-acceleratingslowing-down/page-9

Found that the 14's may have a TSB for tightening the nuts on the leaf spring U bolts.

The 15's have no such fix. So just for the hell of it, I climbed under the truck with my trusty torque wrench, and started at 20 ft/lbs... yes, 20. And wouldn't you know, every damn bolt turned 1/8 to 1/4 turn before it clicked! Torque spec for these bolts is 78 ft/lbs! I upped mine to 50 just to test.

The difference? Night and day. Shifting now feels like my '07 F150, tight and smooth.

Half second gear changes, clunk while coasting down hill and applying gas, clunk while coasting up hill and switching from 2nd to 1st, and shuttering from 3rd down to 1st.... all gone!

I finally have the truck I signed for!

 

Just thought I would pass this along to anyone interested. Free fixes are the best.

Why are these bolts not tightened?

[joeisalsocool]

Why? who really knows. Maybe this batch was built on a Friday afternoon. The real question is, how did these trucks go through initial testing when these bolts were practically hand tight?

[jonboy77]

I am having the same type of issue. Right at 30 mph while gas is being applied normally, when I let off the gas I get a really bad metallic clunk that sometimes sounds like a muffled backfire (just to say that when it's not as hard that is what it sounds like) but it is defiantly a clunk when i let off the gas and the truck downshifts. Happens when pushing gas (normally) while excelling, speed is over 25 but under 31 mph, I let off the gas, truck decellarates normally, then downshifts---CLUNK. A very noticeable clunk. When I get it in the grove I can repeat the clunk everytime. Back to back. Talked with dealership and was told he understood exactly what I described and it was NORMAL OPERATION. First of all I love my truck. But I want this fixed. To me this IS NOT normal operation. I struggled between getting the 6.2 or a diesel. Because the 5.3 was the practical decision for me that's what I went with. But I want to lift, exhaust ect but do not want to void warranty having issues. I am going to take it back to the dealer and hope they fix it.

 

I am the type of guy that will keep the truck for 20 years if it will keep me that long. Lol. My other truck is a 2000 Nissan Frontier I bought wrecked in 2003 rebuilt with 31k miles. I still have it. It runs great but everything else is starting to wear out so I will use it for hunting. I have saved for my SLT for awhile. Was torn between Ford and GM. Still think I made the right decision. The other option I thought about was buying a older c10 or 70s GM and send it to Gas Monkey get it fully restored with a lot of awesome electronic features and a huge motor and super chargers. Now I kind of do wish I would have done that.

 

But anyways back to my original problem and what this thread is actually about, What you guys think?

[pm26]

Why? who really knows. Maybe this batch was built on a Friday afternoon. The real question is, how did these trucks go through initial testing when these bolts were practically hand tight?

I bet that the trucks that are used for initial qualification testing receive much better quality control at all levels. They would definitely check and recheck tightness of critical fasteners on such trucks and make sure wheels/tires meet all specs and are balanced properly.