Who likes their 8 Speed?

[truckin775]

On ‎10‎/‎18‎/‎2018 at 4:51 AM, Kubs said:

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.

Ill be putting AMSOIL in the engine and tranny sooner than later. 

[samckitt]

Mine is in the shop today for another fluid change.  I recently asked the service rep about this new fix coming out in 2019, she said she didnt know exactly what it was, but said something about a new fluid formula that GM will tell her to do first before this other fix coming out in '19.  So that's getting done now.  We will see what happens, not holding my breath.

 

[Srode1]

On 11/2/2018 at 11:43 AM, samckitt said:

Mine is in the shop today for another fluid change.  I recently asked the service rep about this new fix coming out in 2019, she said she didnt know exactly what it was, but said something about a new fluid formula that GM will tell her to do first before this other fix coming out in '19.  So that's getting done now.  We will see what happens, not holding my breath.

 

Will be interesting to hear about the new fluid.  

[samckitt]

So they did nothing because mine already had this new fluid.  It was in for torque xonvertwe swap back in june and they put this new fluid in it at that time. And to be honest, it feels worse now than it did before i took it in. I need to read what all they did to it. Dont know if they cleared the TCM and it jas to "relearn" my driving habbit. 

[SILVER SLED]

2 minutes ago, samckitt said:

So they did nothing because mine already had this new fluid.  It was in for torque xonvertwe swap back in june and they put this new fluid in it at that time. And to be honest, it feels worse now than it did before i took it in. I need to read what all they did to it. Dont know if they cleared the TCM and it jas to "relearn" my driving habbit. 

The new fluid is not out yet.  

[samckitt]

Ah ok. I must have the latest at this point then. 

 

She also said my shuddering is from it switxhing from V4 to V8.  I said no thats not it. It happens in V8, so i have to take it back in and let her hook it up to some computer when it happens to send to GM. 

[Mattbmx63]

My 2017 8-speed had the flush at 22k, they just did a converter at 31k. Got it back, 100 miles later shuddering is back. It shifts worse now than ever and it seems to rarely go into V4 mode now. Not sure if they are doing something with programming as well. I have to go back and ask. I was told the new converter most likely is the same just from a different vendor. 

 

Anyone have any clue what is really going on with these things? They mentioned final fix beginning of 2019....

[samckitt]

Have had mine back almost a week now. Paperwork says i had the latest programming, fluid and TC, yet i feel like it shifts worse now than before i dropped it off, and all they did was lube the rear leaf to stop the clunking. 

[Roscopcoletrain]

Had mine back for a bit over a week. Smooth as butter. TC replaced, fluid and filter done. 

[SizzlingSkilletz]

This is a follow up on my post on page 41, I had a shudder at 1500rpms, Black02Silverado posted (bottom of page 40) to send Amsoil for a complete fluid flush to see if that would take care of the issue. I took my truck in for the shudder and they did a flush and filter with the Amsoil. I waited awhile to post my results to see if it would come back. It has not

Now 60 days later and 2000 miles later everything is perfectly fine, shifts great! so the Amsoil flush worked great for me thanks to Black02Silverado for supplying the fluid!!

[Srode1]

5 hours ago, SizzlingSkilletz said:

This is a follow up on my post on page 41, I had a shudder at 1500rpms, Black02Silverado posted (bottom of page 40) to send Amsoil for a complete fluid flush to see if that would take care of the issue. I took my truck in for the shudder and they did a flush and filter with the Amsoil. I waited awhile to post my results to see if it would come back. It has not

Now 60 days later and 2000 miles later everything is perfectly fine, shifts great! so the Amsoil flush worked great for me thanks to Black02Silverado for supplying the fluid!!

Glad they got it flushed for you, but I wouldn't jump to conclusions that it's fixed.  2000 miles isn't much driving, my problem took about 20,000 to show up the first time, and another 15,000 or so to show up again after the first flush and 'new and improved fluid' from GM.  If you go 30,000 without it coming back, I'll be convinced Amsoil is a good solution to the problem.  

 

[samckitt]

Have been fighting a shudder with this truck, it has 15k miles on it & has been in the shop a few times for it (still under warranty). What I feel, almost feels like a miss fire, but no check engine light. When driving at constant speed, occasionally I will feel something, like a random miss fire, and when slightly accelerating I feel it a lot, 10-12 times a second. Trans fluid was changed, nothing, changed torque converter, nothing, had it in last week for oil change & they changed the trans fluid again, said there was a new fluid out. For about 200 miles it felt different/better, (I was actually smiling driving it) it shifted when I felt it should, & didnt notice the shuddering. Now today on my way to work, it felt like it was back to the way it was before the last fluid change. Somewhere I read this transmission is a "learning transmission". Maybe they reset something while it was in the shop & now has "learned" how I drive & is trying to adjust for it....????

So my question, is it possible that this is something electronic/PCM causing the shuddering? If so, can this be turned off so it doesn't "learn" from me....?

[Srode1]

There is supposed to be another fix available now after the new fluid doesn't work.  Details haven't been shared on the board yet - relearning wouldn't solve the shudder issue.  I would go back to the dealer and let them know the fluid fixed it for a while but it's back.  They should implement the next fix then. 

[Chainesaw]

I had a '15 6.2L and absolutely hated the transmission. When I first got the truck, I had no issues at all.. took it in for an oil change and they had some kind of "service update" - They SAID it was just changing out a harness or something...  but from that day on, it was a piece of shit. Had it flushed twice and a new TC installed.. nothing helped. I bitched about it every time I took it in for service, and the Service write was just like "yeah, everyone says the same thing" - It was at that point that I knew it was never going to get any better and it was one of the reasons I traded it in on an '18 Denali - and so far, the transmission has been awesome..  none of the other transmission issues the '15 had.

[2018GMC]

There is a detailed post about the new fluid on this forum. I think newdude or MichiganHD posted it. Basically says the stock transmission fluid (2014 - 2019) is hydroscopic and adsorbs moisture (like brake fluid). After so much moisture is absorbed into the ATF, it affects shifts and causes shudder or RPM bouncing when cruising. (torque converter locking unlocking)

 

i have 6800 miles on my 2018 6.2 8L90and it’s been ?. Hope / nervous ? that doesn’t change. 

Edited March 7, 2019 by 2009GMC