GM 8 Speed Transmission. On the new GM 1500 Trucks

[flyingfool]

try the trans re-learn procedure at the dealer

[flyingfool]

fast learn

fastlearn(1).pdf

[GullLakeMi]

On 12/10/2020 at 11:05 AM, Ecochef said:

My truck has the 19' 1500 4x4 5.3L with the 8speed and i constantly have a hard catch, notchy feeling shift between first and second at low speeds at various times.  Like it doesn't catch and then lurches forward or back (if in reverse).  Taken it the dealer several times and because the techs can't 'replicate it' I'm SOL.

Can't help but pile on here.  Same with my '16 6.2L 8 speed.  I take my kids to school most mornings and they comment on the hard low speed shifts.  I hate spending time at the dealer and let them win the "we can't reproduce it game".  I've ignored it for a long time.  I'll be trading in soon.  I guess the positive is it has never left me stranded.  

[SILVER SLED]

My '18 8 speed with a 6.2 was a great transmission.  Always smooth.  Wonder if the '17 and newer vehicles with the updated electronics made a difference in drivability.  

[Chevrolet1]

My 2019 5.3L / 8-speed only has 7k miles and, when I bought it a few months ago, noticed two concerns. After a trip to the dealer, they updated the TCM and changed the fluid. Now it drives and shifts great, no issues. Newer models (2020+) will come with updates from the factory that address these concerns. The biggest issue(s) with the 8-speed were with the prior generation trucks (up to 2018). 

[dobroplayer]

I drove the 6.2 8 speed for 3 years in a 2017 GMC and had nothing but trouble. Never was right. My wife bought a 2019 and they STILL hadn't fixed the issues 2 years later, and had to have a tranny flush before the first payment. 

 

I can say that my new 2020 6.2 with the 10 gets now where near the MPG, and I don't think it is as quick, even with the "performance package".

 

I personally would be leery of the 8 speed. Just my $.02...

 

[pokismoki]

https://gearsmagazine.com/magazine/wham-bam-another-8l-related-shift-concern/

[beepbeepimmajeep]

I've got a 2017 6.2 with the 8-speed and 84K, no issues. It shifts a little on the firm side when cold but not harsh. No clue if the fluid has ever been done, but I will be doing it here shortly.