Who likes their 8 Speed?

[JacobC1983]

How many miles to get out of learning mode? Mine was clunking like crazy up to the point I got rid of it around 9800 miles.

[Greg the leg]

My 2015 Denali, 6.2/8 speed had a weird intermittent vibration that will last a couple seconds at 60 miles an hour after I had it a months. It was like driving over rumble strips, then stop , then do it again 10 seconds later, a few times,then not do it again for a few days. Also the tach would jump up 100 rpm when the vibration was occurring .That went in for a year before I read other people were having the same issues that were caused by the torque converter not locking up.

I brought it to my GMC dealer when it was having a episode and they drove it and they said Yep there's a problem .

I left it there while I was away on a weeks vacation. When I got back from vacation I went to the dealer and they did have it all fixed new torque converter and reprogrammed the ttransmission no problem since,thank goodness.

Happy as a Lark- now

[JacobC1983]

I added poll in a different thread for all you 6 speed having people who would like to discuss their transmission pros and cons. I am interested to see if the % of users sways the same direction.

[Stingray427]

Im curious who has 2017 with 8 speed issues. I'm starting too think that maybe the big diesel isn't for me but I'm really concerned I'm be getting same problem. It's the only reason why I'm concidering the diesel in the first place. Have no need for it and I really liked my 6.2.

[Stingray427]

I have a 2017 with 8 speed with 700 miles and the trans has started its shudder/shake below 1500 rpms. Going back to the dealer Monday. I can't believe after all these problems for 2 years Gm is still putting this bad converter in 2017s??

[DLW66]

2017 6.2L 8 speed as well with 600 miles, no issues, love it so far.

[silver sled 16]

I have a 2017 with 8 speed with 700 miles and the trans has started its shudder/shake below 1500 rpms. Going back to the dealer Monday. I can't believe after all these problems for 2 years Gm is still putting this bad converter in 2017s??

.... ahhh shit!...this new truck gives me any trouble the D or the F word will be coming out of my mouth in more ways than one. Maybe it's true. Gm really did give up on the 8 speed in favor of new 10 speed. Edited January 14, 2017 by silver sled 16

[Stingray427]

Is that the dodge and ford word or the damn and f**k word?? Lol. Both about the same to me.. I'm too damn hard headed and loyal to leave Chevrolet so they'll just have to fix it or I'll try another one. I do absolutely love the 6.2... Think is a beast.

[mookdoc6]

I doubt on Tech after the FAST LEARN Procedure goes out and drives it for 30+ miles using the ADAPTIVE DRIVE FEATURE that requires long driving distances and precise actions to DIAL IN the Clutches etc. The service advisor I talked to said, "I been doing this for 15 years and there is no such thing as adaptive transmission that the Tech is supposed to drive around it's all done on computers here in the shop"

 

I had him print out the 8L90 Adaptive Shift Refinement and he did. No comment after I showed him what he just printed out. I then asked him what Tech is going to Drive and where would he drive for 5 miles straight without stopping between 1000rpms and 1600rpms? This is like the 6th Largest metropolitan area in USA bro! Your not going anywhere for the next 30 miles without Cars/stoplights etc every couple blocks.........Nobody here is going to follow this and most likely nobody here even knows to do this?

Edited January 15, 2017 by mookdoc6

[dodge stomper]

Love mine on a 2016 1500 ltz but did have to replace Torque converter at 4k miles. No issues since then 8k now

[Jtodd]

After speaking to a service manager and he telling me there is no fix for my 8 speed..and it is true there focus is on there new 10 speed..I made the decision after a year of dealing with dealerships and GMC.. to hire me a lawyer...after a 3 month wait I received a nice settlement from GMC..I hated it!!!!!

[mookdoc6]

After speaking to a service manager and he telling me there is no fix for my 8 speed..and it is true there focus is on there new 10 speed..I made the decision after a year of dealing with dealerships and GMC.. to hire me a lawyer...after a 3 month wait I received a nice settlement from GMC..I hated it!!!!!

 

 

Did he also mention to you that GM is not going "focus" on anything higher that 10 speed too? Please they plan on fully supporting the 8speed......

[dodge stomper]

I THINK many DEALERS ARE HESITANT to replace the Torgue converter. Why? I have no idea but when mine was replaced it was like a new truck. A member above discribed it as like those rumple strips and that is exactly how I described it to my dealer. Though mine was not only at 70-80 but was intermittent anywhere. at times 35, at times 80... I think it is/was a faulty TC...

 

DS

[muhsfink07]

can I ask them to do this on my 2016 5.3L 8-Speed? i have the same symptoms that it seems like a torque converter replacement and flush would fix...

[MrNasty]

Just had mine fixed on 2015 8 speed. Replaced torque converter, stator support assembly, flushed the trans and replaced filter, reprogrammed tcm, and did adaptive relearn according to them. Mine didnt have the shake but rpms fluctuating at steady speed on flat ground and harsh shifts as well as delayed shift onto reverse then delayed shift into drive. It shifts great now and no delay anymore. Rpms are rock solid.

 

I had to print the tsb's and make sure the trans tech got them. Only problem I had after that is the dealership had mine and my wifes truck mixed up in there system. So they ordered parts for her vin but she has the 6 speed.

 

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