Loud transmission clunking after acceleration

congden · September 5, 2016

Ive got a 2016 1500 5.3 z71 with the 6 speed, 7700 miles.

After average/ slightly hard acceleration, (around 30-60 MPH) then letting off the pedal I feel and hear an metallic clunking noise coming from the transmission area. Sometimes its light and slightly noticeable other times it is quite loud and you can literally feel it shake the truck. Has anyone else had this issue or had it resolved.

I have taken it to a few different dealers to get it diagnosed and have been told it is a characteristic of "certain trucks with the 6 speed" however I have driven several other identical trucks and cannot duplicate the issue, my father also has an identical truck 16, CCSB Z71 5.3/6 speed and we cant get his to make the same noise. Being told that a loud clunking noise in a brand new vehicle is "acceptable" is ridiculous and it seems as if I just happened to get stuck with a truck that makes the noise while others don't.

WLC · September 5, 2016

Try tighting u bolts or spring clamps. Helped mine but still does it a little. GM says live with it. How's your radio reception on FM side?

congden · September 6, 2016

The u bolts are tight, i have not noticed an issue with radio reception but then i have not traken the truck too far yet

BIGDOGx · September 6, 2016

The u bolts are tight, i have not noticed an issue with radio reception but then i have not traken the truck too far yet

It is actually as intended, or design trait i should say. Full size GM trucks have done it in some form or another for decades now, my 05 silverado did it, my 95 s10 zr2 did it a friend that has a gmt-900 version does it too and as expected my 14 sierra has the same clunk issue from time to time. Not sure if it is due to the same slip yoke issue of the past or if it is axle wrap but one thing is for sure, i doubt very much your dealer will have a fix for you. I have almost grown accustomed to it sad to say, thankfully it does happen far less then what my 05 use to do.

congden · September 6, 2016

I have driven exclusively GM trucks 2000+ and have never heard this noise as prevalent as this before in GM or any other new truck.I agree that it may be "normal" " acceptable tolerances etc.." But the level of noise is not, I have driven several other identical 16 5.3/6speeds and cannot duplicate it. My wife even comments on it and you know it's loud then.

Motor Guy · September 8, 2016

My 2016 Silverado LTZ is in the dealership for the second time right now for this clunking, banging issue.

First time they cleaned some valve body, said it was sticking. No difference.

First day I had the truck , I was going down a small grade and the transmission was holding the truck until it let out and extremely loud crack/bang and the truck lunged forward.

Transmission has been garbage ever since.

As I said its in for investigation right now, so we will see what happens.

Active lane management and front camera have given out as well.

2400 kms

Colossus · September 8, 2016

My old 07 Sierra and 99 Silverado both did this to some extent. Similar things were very noticable in the old Ford work trucks a previous company had as well as the 92 Explorer my dad had since new from 92-2001. CLUNK! CLANK! Gah.

congden · September 11, 2016

My 2016 Silverado LTZ is in the dealership for the second time right now for this clunking, banging issue.

First time they cleaned some valve body, said it was sticking. No difference.

First day I had the truck , I was going down a small grade and the transmission was holding the truck until it let out and extremely loud crack/bang and the truck lunged forward.

Transmission has been garbage ever since.

As I said its in for investigation right now, so we will see what happens.

Active lane management and front camera have given out as well.

2400 kms

Let me know how you make out or what the diagnosis is. GM customer service is helping me out right now and il see where this leads, I have already had it to the dealership (4) separate times at 3 different dealers. I know that not all 16's do this so I am hoping that they can work something out for a swap or whatever.

Motor Guy · September 13, 2016

So as promised, here's the update so far.

Truck is still at the dealership.

Been advised that the trucks computer has been reset to factory (as new).

Vehicle has to be driven, in order for the transmission to "LEARN" driver patterns................. seems a little strange to me!

lee16silverado · September 13, 2016

So as promised, here's the update so far.

Truck is still at the dealership.

Been advised that the trucks computer has been reset to factory (as new).

Vehicle has to be driven, in order for the transmission to "LEARN" driver patterns................. seems a little strange to me!

It's a closed loop system self-regulating system. IE, the computer adjusts fuel parameters so that it maintains a 14.7:1 A/F ratio. There's a host of other parameters that self adjust based on the individual system, since not every engine or transmission is exactly the same. And you're right, that does seem strange for the dealership to tell you that. It's not really learning how you drive, it's learning how it's own system functions, which by the way doesn't take very long at all. It's a common excuse for why your engine or transmission doesn't feel right, hoping you just get used to it.

pm26 · September 14, 2016

No amount of "learning" is a substitute for lousy dimensional tolerances.

congden · September 19, 2016

So as promised, here's the update so far.

Truck is still at the dealership.

Been advised that the trucks computer has been reset to factory (as new).

Vehicle has to be driven, in order for the transmission to "LEARN" driver patterns................. seems a little strange to me!

Did that seem to solve the problem? GM customer service is giving me a $500 accessories credit because I complained so much but that's only going to buy some Genuine GM chrome door handles. I believe my dealer reset the trans as well but it still does it just as bad as before.

f8l vnm · September 19, 2016

my 2004 clunked , my 08 clunked , my 14 clunked and now my 16 also clunks as well. I'm not saying I'm cool with it by any means but I have learned to let it go. funny thing is my buddies 16 F150 Lariat clunks too. I remember he used to rag on me and after some research it seems like some f150's also clunk as well. ( Check the ford boards)