Who likes their 8 Speed?

JacobC1983 · May 14, 2016

As the title states.... My 2015 GMC Sierra with the 6.2L and 8 Speed is at the dealership again with a field service engineer hoping to fix the transmission for the 5th try.

I will trade it in on another GMC Sierra.. and I want the 6.2L again. As you know, this sticks you with the 8 Speed transmission.

So.... Who has a trouble free 8 speed transmission? I have read many threads of problems, but hope to find those without problems to make the final decision: Do I get the 8 speed again in the 2016 model or do I downgrade to the 5.3L and the 6 Speed.

Please put in miles and year of your vehicle with any explanation you want in the thread.

Edited May 16, 2016 by JacobC1983

The Mad Veteran · May 14, 2016

Could this be your issue?!

http://www.gm-trucks.com/forums/topic/186752-interesting-progress-with-odd-trans-behavior-2015-6-speed/

JacobC1983 · May 14, 2016

That doesn't work for the 8 speed trucks, thanks though. I have tried it, and many others in the thread with 8 speeds haven't had luck with it.

buckwuk · May 14, 2016

Mines been great. 28000 miles it's always smooth. But in tow haul mode downshifting from 2-1 it's been a hard shift maybe 5 times..I still really like it

2015AT6.2 · May 14, 2016

I absolutely love my 8 speed. I'm right at 6k miles in about 9 months. It's been nothing but great after it learned my driving the first few weeks. Never had any clunk, slack or anything of the sort.

JacobC1983 · May 14, 2016

This is good to hear. Makes me think there is hope for me! Thank you for the comments.

sicsixxx · May 14, 2016

Works good........most of time. Still clunks here and there most likely due to gear hunting. I am at only 1000km so more time needed for tranny to adjust. It really it isn't bad and provides seamless shifting a majority of the time. Just wants to shift up all the time.

JacobC1983 · May 14, 2016

Do any of you get large clunks that feel like they shake the whole driveline? Small noises (clunks) I can deal with, but about once a week I get a large, loud sounding clunk that emanates through the entire driveline.

goliath51989 · May 14, 2016

I like my 8 speed, no issues so far, 15' 6.2L Denali w/ 15k miles

JacobC1983 · May 14, 2016

I see most of you that have replied have a 2015, which is the same year I have. I was curious of there was a correlation between people who liked their 8 speed and people who didn't and if they had a 2015 or 2016 model. I read there was a possibility of an updated 8 speed transmission with a new torque converter and valves in the 2016 model.

Maybe I am just one of the unlucky ones.

Edited May 14, 2016 by JacobC1983

Vic15 · May 14, 2016

My 8 speed seems to work well, as I never give it a second thought. I really never give it a first thought for that matter, it just works with about 7,500 miles.

Cosmic Charlie · May 14, 2016

How can I see the results if I can't vote ? (no 8 speed ...)

FADEC · May 14, 2016

As the title states.... My 2015 GMC Sierra with the 6.2L and 8 Speed is at the dealership again with a field service engineer hoping to fix the transmission for the 5th try.

I will trade it in on another GMC Sierra.. and I want the 6.2L again. As you know, this sticks you with the 8 Speed transmission.

So.... Who has a trouble free 8 speed transmission? I have read many threads of problems, but hope to find those without problems to make the final decision: Do I get the 8 speed again in the 2016 model or do I downgrade to the 5.3L and the 6 Speed.

Please put in miles and year of your vehicle with any explanation you want in the thread.

New member here but a long time visitor to this site. Had to comment on my 8 speed. I have a 2016 Sierra SLT CC 4x4 5.3 and 8 speed. I have owned four GM trucks, three bought new one used.

The trans on this one is by far the harshest shifting tranny I have ever had on not only a GM vehicle but any vehicle. LOVE the truck except for the trans. Hard shifting, usually downshifting, but upshifts hard with a light throttle. By far the most annoying is when slowing down to stop right before coming to a complete stop is annoying bump/jerk feeling. Almost feels like some one ran into your rear end at slow speed. Have tried the grade braking turn off trick but no change...I think it mainly works for the 6 speed. BTW I had the same 6l80 trans in a 2009 Avalanche and it was butter smooth. I personally feel the tranny is good just the programming is very poor.

JacobC1983 · May 14, 2016

That is how mine acts, slowing down to a stoplight I can get some VERY large clunks. Feels the the transmission is going to drop out of it. This happens about once a tank a gas for me. On other days I will fire it up in the morning and drive to work and it is butter smooth. Then the next day it will be a clunky piece of garbage.

That is why I opened this thread.... I wanted to know the % of people who love their truck's 8 speed transmission VS. the % of people who hate their 8 speed and see if I was in the minority.

Edited May 14, 2016 by JacobC1983

FADEC · May 14, 2016

That is how mine acts, slowing down to a stoplight I can get some VERY large clunks. Feels the the transmission is going to drop out of it. This happens about once a tank a gas for me. On other days I will fire it up in the morning and drive to work and it is butter smooth. Then the next day it will be a clunky piece of garbage.

That is why I opened this thread.... I wanted to know the % of people who love their truck's 8 speed transmission VS. the % of people who hate their 8 speed and see if I was in the minority.

Have never experienced a "butter smooth" shifting with this trans. Some starts, stops, better than others but never smooth. BTW truck built 12/15 4,100 miles.