2016 Sierra 5.3 8-speed

[Sierralt]

Hey all, recently picked up my 2016 all terrain, it has the 5.3 8 speed, love my truck love all the sierra's I've owned 2012, 2014. I notice at low speeds with new transmission it's a bit.. Clunky as it seems to change gears to quick, straight away no problem however turning out of driveway or turns at low speeds it's noticeable

.. I can live with this.. However last 2 trucks have been tanks for winter driving, with blizzaks they didn't move, wonder how this will affect next winter driving? Mainly accelerating and such.. Any insight on the 8-speed for winter conditions?

[Rme2513]

I live in the south so no winter driving but mine always jumps to the next gear to quick even more after you turn a corner and wanna pick up speed if you not in the gas as you turn it will up shift as soon as you give it gas and another thing if you yielding and don't come to a complete stop it will stay in second and as soon as you give it gas it will jump to first and kind of lung the truck. I have had my transmission replaced because of the other problems but I think this is just the way it's going to be with the new ones with so many gears

[Sierralt]

Yes I couldn't agree more with everything you said

[beach3141]

I have the 8 speed in my 2015 Silverado LTZ Z71 with the 6.2. It displayed the same characteristics as far as the transmission wandering when accelerating at low throttle, as well as hard clunking noises when off throttle cruising down the boulevard following traffic, then getting back on the gas slightly. The clunking noises seemed intermittent, however they were annoying to me, so I took my truck to the dealer and had them look into it. They did a software update as part of a service bulletin, and replaced the torque converter. The wandering shifting tendency no longer exists, as the transmission seems to shift up the gears as one would normally expect. I still get a bit of a clunking noise from time to time - not quite as often nor as severe as before. I was also told that a lot of what my truck exhibited was "normal" and is attributed more to 4WD trucks than 2WD. This is my first 4WD truck so I'm tempted to take their word for it. The service guys at the dealer have been taking care of my vehicles for quite some time, so I like to think I've getting the straight scoop. Thoughts? Do 4WD trucks have "looser" feeling drivetrains than 2WD? Do locking torque converters and differentials have a lot to do with this sort of behavior, as far as the knocking noise is concerned

[CounterMeasure]

Do 4WD trucks have "looser" feeling drivetrains than 2WD? Do locking torque converters and differentials have a lot to do with this sort of behavior, as far as the knocking noise is concerned

 

A 4WD system has more interlocking components with a transfer case inline to the rear wheels compared to a 2WD driveline without it. As such, more stacking gear lash clunking when things press one direction as you coast, and then all must switch the other way when you apply power. Some trucks will clunk more than others if they have more components on the looser end of the lash tolerances as well.

[beach3141]

 

A 4WD system has more interlocking components with a transfer case inline to the rear wheels compared to a 2WD driveline without it. As such, more stacking gear lash clunking when things press one direction as you coast, and then all must switch the other way when you apply power. Some trucks will clunk more than others if they have more components on the looser end of the lash tolerances as well.

 

Thanks for the clarification... I'm glad to hear that I wasn't just being given a line by my service department... that's all too common now days, it seems.

[mookdoc6]

Yup, they inherently make more noise no doubt!

[mookdoc6]

Tried to recreate your situation today with my 2wd 2016 GMC 5.3 with 8speed. It exhibits none of ill gotten tendencies like yours. Knock on Wood! I did find something new though while trying to recreate your turning behavior.

 

When i plunge out of parking lot or drop down a steep grade coasting and apply foot accelerator I get a goofy tranny feel in 1-2

That is all I have noticed with mine.

[Sir Dan]

2016 5.3 8 speed here too. I also noticed the trans sometimes wanting to shift up to higher gears way too soon and clunking on downshifts. I recently turned off the DOD (AFM) with my diablosport tuner and the difference is night and day. Smooth, consistent shifting now so I can only assume these issues are related to AFM. Diablo does not yet offer a tune for the 8 speed so I couldn't change anything with the trans computer but just turning off the AFM without changing any other parameters made a very noticeable improvement.

[silveradoss_3]

I'm curious, does gm offer the 5.3 8 speed combo in a single cab too? Or is it just for the CC?

[mookdoc6]

I am waiting for a 5.3 8speed diablosport tuner for my truck! I find this new 8speed a world of difference better than the 6speeds! Mine seems to be getting even better the more I drive it. Really the F'n tranny has to learn my driving? **** that remove the educated idiot engineer and put a F'n mechanic on the task of making a 2016 era transmission Shift correctly each and every F'n time because it's supposed too!

 

I have had annoying Tranny's there are like annoying wives and you will do whatever it takes to get away from it!

[SierraMyst]

Hey all, recently picked up my 2016 all terrain, it has the 5.3 8 speed, love my truck love all the sierra's I've owned 2012, 2014. I notice at low speeds with new transmission it's a bit.. Clunky as it seems to change gears to quick, straight away no problem however turning out of driveway or turns at low speeds it's noticeable

.. I can live with this.. However last 2 trucks have been tanks for winter driving, with blizzaks they didn't move, wonder how this will affect next winter driving? Mainly accelerating and such.. Any insight on the 8-speed for winter conditions?

Mine does the same thing. When o pull out of my driveway in the morning, which is a straight shot, the only thing I feel is the immediate shift to 2 at 5mph.

 

Pull out of work is a different story since it's all very slow droving. I pull out of my parking spot for 10 feet ( clunk into 2nd) and make a right turn. Drive about another 15 feet and make another left turn (clunk in to 3rd) then hit a stop sign (clunk down into 1st).

 

If I just take off and go in a straight line, no problems.

 

But man driving about slowly like through a parking lot trying to find a parking space. What a mess. And the best thing is that it "all perfectly normal".

 

This is my first and last GM vehicle.

[Sierralt]

Yes unfortunately this is the way they are made, I'm sure it's a shot at saving mileage, you do get used to it however.. Love the 8 speed for acceleration in tighter situation.. Little more feel for the vehicle.. Less like a insults truck, Don't give up on GM yet, I still love my truck.. I'm sure you can adjust it at the dealership but I'm used to it now

[mookdoc6]

Yeah, tell them to run updated flash or make damn sure their is the new torque converter in yours depending on build date! If none of that helps I guess get the Diablo tune like everybody else which had this problem and now seem to really like the feel of Tranny!

[Srode1]

Mine does the same thing , 6.2 2015 with 2000 miles on it. I'll take it in and see if they can improve on it although I do notice it's worse when I baby the truck then when I'm driving more aggressively (not hot rodding it). Coming from a 2004 GMC 2500HD 4x4 Duramax with an Allison transmission that was silky smooth shifting since the day I picked it up new, I am disappointed in this new truck's shifting. Being a 4x4 shouldn't have an impact on shifting, every vehicle I've owned since 1991 has been a 4x4 and none of them have shifted clunky. It's a programming issue. That it's intermittent shows its not design or tolerance stack up. Tolerance and stack up would show up all the time.