And update for the better? Clunk be gone?

GsBowtie · October 27, 2015

After driving my truck, post re-call for a few weeks now, i can safely say there is some improvement, but it's not dramatic improvement. I still have some low speed transmission confusion going on, perhaps a bit better than it was before the update. I still feel that GM needs to release a TCM update to correct this issue. Either that or once I'm out of warranty, then I'll try a BB tune. I hear so many good things about them.

I am concerned about doing a tune since i pull a 6k lb camper with my truck and i understand the BB removes a lot of the torque management that's in place to protect the drive train. But maybe that's not a valid issue?

Tattooo · October 27, 2015

Mine helped a great deal.....reduced the clunk to once and a blue moon

JimmyVal · October 27, 2015

Just got mine back and I have to say it's much better. I drove about 25 miles and after a while, forgot about the shifting. It's much smoother and no 2nd to 1st clunk. So far I'm happy.

afireinside7444 · October 29, 2015

Same here got it 2 days ago and much much better silky smooth now

lefty421 · October 29, 2015

I had the update done yesterday while at the dealership for an oil change.... I did not notice any difference whatsoever, although, I wasn't having any issues before bringing it in.

No Tyme · October 29, 2015

I want to throw something out here concerning this software update: As with cell phones and computers etc, which run off of software specifically written for those items, and reading about cell phones that become problematic after firmware updates or different apps not working correctly as well as computer updates and software issues that I know all of us must have seen at least once or more in this tech heavy times we live...

Could this be a corruption of the existing software that is in the trucks that leads to some of us "seeing positive" results and others not?

This is a question for some GM techs or others more affluent in the understanding of the software systems in the automotive industry.

miles5241 · October 30, 2015

I want to throw something out here concerning this software update: As with cell phones and computers etc, which run off of software specifically written for those items, and reading about cell phones that become problematic after firmware updates or different apps not working correctly as well as computer updates and software issues that I know all of us must have seen at least once or more in this tech heavy times we live...

Could this be a corruption of the existing software that is in the trucks that leads to some of us "seeing positive" results and others not?

This is a question for some GM techs or others more affluent in the understanding of the software systems in the automotive industry.

This is the angle I was looking at it from. Being a Systems Engineer, it only takes one little thing to corrupt the rest, I've seen RAIDs fully fail due to a firmware update on a SAN controller loosing TB of data that was supposed to fix something completely different.

It could have been something they programmed in the TCCM from the factory that was supposed to work with the torque management system in the TCM, but instead just worked against it creating the issues that most of us experience. It may have been overlooked in R&D or ignored to get the product out the door. This commonly happens with software. There is a reason Windows is constantly updating, it only takes one bad line of code to make a world of hurt. When Target was breached in late 2013 it was only 1 line of code...millions of credit card numbers stolen.

But just like any other software you may see a different results among different hardware, it may have been a specific build number on the transmission that didn't agree, or the transfer case. To many variables these days to say, "Well its got Spark, fuel and compression, its gotta work..."

Also after driving it for 1000 miles it still seems to have stuck, shifts from 1-2 and 2-3 are still worlds better then when I drove it off the lot. Traffic still sucks...

tnchevy · October 30, 2015

Going in Monday for update. My truck has never shifted too bad but does get the occasional 1-2 or 2-1 shift that feels like the truck is going to come apart. Now if GM can just figure out how to get my radio to actually pick up a FM station........

juststillin · October 31, 2015

Had the update on Wednesday. Feels like I am driving the truck I hoped it would be when I bought it. I admit to some OCD but I just didn't believe the shuddering and the clunking were normal as was relayed to me by two dealerships prior to the update. I'm also curious why some trucks improve after the update while others don't. Perhaps it's the code issue mentioned above. These things probably have more lines of code than the original lunar lander. I'm not a gearhead, but could the difference also possibly be linked to the 3.08 vs. 3.42 differential? My truck is a 4X4 5.3 6 speed Z71 with the 3.42. Hoping this gets fixed for everyone as these are otherwise awesome trucks.

JimmyVal · October 31, 2015

I've now put over 300 miles on my truck since 15304 was performed and I have to say I cannot believe the improvement. It's hard to believe a transfer case programming correction could have such an effect. Even my wife noticed the improvement. It's like driving a different truck! I find it hard to tell when it's shifting. Smooth as silk.

Can't say if the differential makes a difference in how this update changes the tranny shifting, however I have the exact same combination as justillin.

ClemsonFan · October 31, 2015

Does the update apply to all 2014s and 2015s? I called a local dealership today and they said they did not see anything that needed to be performed.

Doobs41378 · November 1, 2015

Does the update apply to all 2014s and 2015s? I called a local dealership today and they said they did not see anything that needed to be performed.

It is decided by your VIN.

No Tyme · November 1, 2015

Does the update apply to all 2014s and 2015s? I called a local dealership today and they said they did not see anything that needed to be performed.

If you have a 4x4 check with the dealer... My 14 is a very early build and I did see improvement... Recall # 01320

Had the update on Wednesday. Feels like I am driving the truck I hoped it would be when I bought it. I admit to some OCD but I just didn't believe the shuddering and the clunking were normal as was relayed to me by two dealerships prior to the update. I'm not a gearhead, but could the difference also possibly be linked to the 3.08 vs. 3.42 differential? My truck is a 4X4 5.3 6 speed Z71 with the 3.42. Hoping this gets fixed for everyone as these are otherwise awesome trucks.

Another good point. I have 3:08 gears but never had and shuttering or clunking: my issues were a flare shift between 2nd and 3rd, corrected by 3,5,R clutch pac replacement: and the "confusion" as I call it while transmission seems unsure if it wanted to shift or not. I even had shifts from 1st to 3rd before... So far it's like a school kid who got the ultimatum to straighten up or you'll get out.

ClemsonFan · November 1, 2015

It is decided by your VIN.

We don't have any more info on it? Mine is a 2015 SLT 4x4. I was hoping this would help with the "clunk" I am getting when letting off the gas and also when coming to a stop.

CounterMeasure · November 2, 2015

We don't have any more info on it? Mine is a 2015 SLT 4x4. I was hoping this would help with the "clunk" I am getting when letting off the gas and also when coming to a stop.

The clunk is very likely to be axle wrap causing slip yoke bind. There are threads on it for clamping the soft springs to remove it. I did it, it went away, but the ride was harsh enough for my wife to complain. And if momma ain't happy, nobody's happy. So off they came, and wrap clunk came back. I plan to get torsion bars installed at some point.

The update for my truck has removed some of the confusion more than anything.