Who likes their 8 Speed?

Srode1 · October 2, 2018

My '15 started shuddering again - about 10,000 miles after the dealer flushed and changed filter and fluid. It was fine up until a month or so ago, so took it in this morning. The dealer just sent an update, they are putting a new torque converter in it, looks like it will take them about a week to get the part and get it done, so I get to use a nice loaner truck in the mean time (not as nice as mine but it works).

ChevyTruckNut · October 3, 2018

Ok, You guys got me bugged! I'm looking at a 2018 Denalli 5.3 with the 8 speed. I can get it for $49,000. Only thing that it doesn't have is the trailer brakes. Have a deposit on it but can pull out any time! I have until Monday to decide!!!!! I'm currently driving a 2016 Chevy LT with a 6" Fabtech lift and 35's. Miss my 2014 All Terrain!

Edited October 3, 2018 by ChevyTruckNut

CK1000 · October 6, 2018

My 2018 slt 8speed with the 6.2 performs great. Much improved over my 2015 slt 5.3 6 speed

Srode1 · October 18, 2018

Well I had my truck in the second time for the 'shudder', and the dealer agreed next step was replace the torque converter - they ordered it and after 2 weeks said it was ready to pick up. They didn't replace the torque converter but instead flushed the system again which of course fixed the issue for now, but they agreed it would come back. The reason they didn't put the torque converter in is while they were waiting for the part, GM stopped that approach to fixing the problem and said a new fix is coming first quarter of 2019 - no information on what the new fix will be however mine should last till then - and there's plenty of warranty coverage left on it so no worries on my end waiting for the new and improved 'fix'.

Kubs · October 18, 2018

I now have almost 9k miles on my 8 speed and not a single issue. I do notice that on colder mornings, if I do not use remote start or let it warm up a bit the first few times it shifts from 1st to 2nd are a little harsh but not bad. After it is warm though there are no issues. I am going to try switching to AMSOIL transmission fluid to see if the improved cold flow properties help with that.

ncd1966 · October 18, 2018

I just traded in my 2015 GMC SLT 6.2 in because of the 8 speed problems.

did the recall when it had about 10k miles on it. Then around 25K I brought it back in for them to look at they said there is nothing wrong with it.

around 40K miles I was having torque converter shutter so I brought it to another dealer and they changed the convertor. So said that should fix my hard shifting; nope. went trade it in yesterday on a 2018 max trailering package slt premium plus 4x4. Its smooooth as silk shifting and even the motor doesn't have a delay when I press the gas.

very happy so far with this one.

BB68 · October 18, 2018

340 trouble free miles here. I dont notice it shifting at all.

too soon?

Bigmac · October 18, 2018

Coming from a 2017 6.2 max tow to a 2018 6.2 max tow ( end of production built) the trans shifting is much better. Haven’t had 1 bad shift yet in 4 k mikes. Seems it holds in gear longer when you let off the throttle and doesn’t upshift so quick. Drove the 17 the other day ( family member bought it) and it is night and day different. Still have t/q shudder on 2018? Oh yes especially when towing but is better in all other aspects. Waiting for tq upgrade as noted above before even addressing it.

ajensen383 · October 18, 2018

Mine has never had any shuttering at highway speeds, erratic shifting at light throttle..yes but that's about it... I never had any downshift clunk or banging into gears either...My truck was built 11/17.. I bought it in 2/18 ...I have 6500 miles on it now and it still seems the more I drive it, the better it is... Now Im not sure if its me, but it seemed to be a lot better after my first oil change..

Volkster · October 19, 2018

Well my '17 6.2 8-speed just had it's first "shutter" at 21,700 miles. As the rest of you, it felt like going over the double yellow line rumble strips when at low load, low rpm. The torque converter wouldn't stay locked up and the rpm's would vary up and down. Just got it back from dealer. They also performed the TSB where they just flush and refill tranny with an "updated" synthetic transmission fluid. I was also told to give it 200 miles and if it happened again most likely they would do another flush and fill. They showed me the TSB where it stated that as of recently they will not change out torque converters anymore as it's not the problem and a permanent fix is coming in early 2019. So far the problem is gone but apparently it will show it's ugly head again after reading this thread so I hope it makes it until the permanent fix comes out.

seamus2154 · October 21, 2018

Well so much for this being a 2015-2016 issue. I have a 2017 6.2 8 speed and all has been great and thought it was fixed. I had the issue in my 2015, 2 flushes and a TC replaced along with a stator shaft. At 16,500 miles now and seeing you fellas with it at later mileage has me concerned now.

TXGREEK · October 22, 2018

Well so much for this being a 2015-2016 issue. I have a 2017 6.2 8 speed and all has been great and thought it was fixed. I had the issue in my 2015, 2 flushes and a TC replaced along with a stator shaft. At 16,500 miles now and seeing you fellas with it at later mileage has me concerned now.

Wouldn’t worry about it, you’ve noticed nothing yet which means you’ll be fine. My 18 6.2 is awesome, awesome enough that I’m spending thousands and thousands in mods that “will not” fit on a 19 or 20...don’t think [emoji848] point is, think positive and you’ll have good things happen with your truck. I love that little clunk I get sometimes, puts a smile on my face every time

Another way of looking at it, by the time you’ve paid off your truck they’ll have finally gotten all the kinks out of the new ones and then you’ll start over, or just keep your beastly machine [emoji6]

Sent from above

Largely Unknown · October 22, 2018

I ran across this article abut changes to the 8-speed affecting the 2019's, which is reassuring to anyone who wants a new truck but doesn't want to spring for the $2500 6.2/10-speed. Maybe this gives some insight to the "fix" everyone is alluding to for our trucks. Perhaps (lets hope) that this will lead to updated parts and/or software for our 8-speeds. Mine harsh shifting and clunking isn't severe at 15K, and is better than when new, but its still annoying.

http://gmauthority.com/blog/2018/07/gm-8-speed-automatic-enhanced-for-2019-silverado-sierra/

Speculation but maybe in a year GM will follow F*ord's lead and install the 10-speed in just about everything.

seamus2154 · October 23, 2018

On 10/21/2018 at 11:08 PM, TXGREEK said:

Wouldn’t worry about it, you’ve noticed nothing yet which means you’ll be fine. My 18 6.2 is awesome, awesome enough that I’m spending thousands and thousands in mods that “will not” fit on a 19 or 20...don’t think point is, think positive and you’ll have good things happen with your truck. I love that little clunk I get sometimes, puts a smile on my face every time

Another way of looking at it, by the time you’ve paid off your truck they’ll have finally gotten all the kinks out of the new ones and then you’ll start over, or just keep your beastly machine

Sent from above

Yeah I am 17 months in and trading will be a slaughter! Also a lot of upgrades put into my truck. I recently sat in two 2019's and can say I am just not impressed. Seems like just improvements to our truck, not worth the coin. Seats were no better which is my biggest complaint lately. The 6.2 is so awesome and what keeps me in this truck, along with the impressive fuel mileage. Trans is still smooth....but everytime I am feeling like a hotshot in my truck I get that nice little "clunk" or "rear ended" bump just to keep me humble and remind me I'm in a chevy!!!!!!! ........or actual GMC!! LOL. Ah new world problems......