Who likes their 8 Speed?

FADEC · May 14, 2016

Seems like most 8 speed owners have the 6.2l. Would be interesting to hear from some 5.3l owners to see if they are affected like me.

bab328 · May 14, 2016

I love mine, 2016 Sierra SLT with 5.3. First 3k miles were a little rough at times but at just under 5k it's now smoothed out.

Very rarely when the truck first starts up and you put it in gear it does a funny thing where it feels like the torque converter won't lock up. When pulling out of the garage (in drive, not on the gas at all) the truck barely wants to move, usually it will roll right out just idling. If I touch the gas at all it takes off kind of like you're "dumping the clutch" for lack of better ways to describe it. The problem goes away within a few seconds and doesn't happen often enough for me to really be concerned about it.

JacobC1983 · May 14, 2016

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.

Have you taken yours in to the dealer? What have they tried to fix it?

Mine had several re-learns and a new torque converter and while it has made the problems occur less, I still get some very large clunking.

Cosmic Charlie · May 14, 2016

I love mine, 2016 Sierra SLT with 5.3. First 3k miles were a little rough at times but at just under 5k it's now smoothed out.

Very rarely when the truck first starts up and you put it in gear it does a funny thing where it feels like the torque converter won't lock up. When pulling out of the garage (in drive, not on the gas at all) the truck barely wants to move, usually it will roll right out just idling. If I touch the gas at all it takes off kind of like you're "dumping the clutch" for lack of better ways to describe it. The problem goes away within a few seconds and doesn't happen often enough for me to really be concerned about it.

sounds like low on fluid - though I doubt it ...

kp52 · May 14, 2016

I love mine, 2016 Sierra SLT with 5.3. First 3k miles were a little rough at times but at just under 5k it's now smoothed out.

Very rarely when the truck first starts up and you put it in gear it does a funny thing where it feels like the torque converter won't lock up. When pulling out of the garage (in drive, not on the gas at all) the truck barely wants to move, usually it will roll right out just idling. If I touch the gas at all it takes off kind of like you're "dumping the clutch" for lack of better ways to describe it. The problem goes away within a few seconds and doesn't happen often enough for me to really be concerned about it.

Here you go:

Sir Dan · May 14, 2016

Was unhappy with how the truck shifted until I switched off the AFM cylinder deactivation with diablosport inTune. Absolutely love the way it drives now! I firmly believe that the 8 speed tranny issues most people are having relate to the trans trying to make up for the loss of power when AFM kicks in.

Badass69 · May 15, 2016

2015 with 21000 miles. Love mine..... delays from park to whatever gear but I really couldn't care less. Shifts good and does what I want mostly. Just have to play with the tuning some more to get my shifts to 6100 rpm or so.

Edited May 15, 2016 by 1994Vmax

JacobC1983 · May 15, 2016

Play with the tuning? I don't want to tune the transmission to get it to shift correctly.... And ruin my powertrain warranty.

Badass69 · May 15, 2016

Play with the tuning? I don't want to tune the transmission to get it to shift correctly.... And ruin my powertrain warranty.

Who cares about warranty.... I don't. Mine shifts absolutely fine... I just want the shift points higher, firmer.. etc... I rather enjoy my truck over the fear of god for some warranty they won't honor anyway lol.

I might see about the TSB listed above as mine is exhibiting that delay issue but I don't think I want some dealer numpty taking it apart and making it worse lol.

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Edited May 15, 2016 by 1994Vmax

JacobC1983 · May 15, 2016

I care about warranty.... It pays for repairs that otherwise I would have to pay for out of pocket. Actually, lots of people care about warranty on a $50k+ vehicle.

JacobC1983 · May 15, 2016

That's my whole point....

If the truck/transmission was tuned they would have denied warranty work on the transmission.

And at this point they are offering trade assistance which I wouldn't have gotten either.

Edited May 15, 2016 by JacobC1983

Badass69 · May 15, 2016

That's my whole point....

If the truck/transmission was tuned they would have denied warranty work on the transmission.

Uh no... the point is tuning won't repair your transmission anyhow. .. What I choose to do with my truck is irrelevant to you.. and my tuning wasn't done as an attempt to repair something because there is nothing wrong with it. If I have to pay out of pocket to fix the delay issue I couldn't honestly care less... but I want to see people having it done and it actually doing as promised as lots of times these shots in the dark nets nothing. You asked and polled for people who like the 8 speed. ... I am one of them. Sucks yours is a lemon but it is what it is.

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JacobC1983 · May 15, 2016

No... The point is if you require warranty work on a tuned transmission the dealer will deny your claim and, therefore, many vehicle owners care about maintaining that warranty.

It does suck that mine requires warranty work, and I am glad mine wasn't tuned because this will end up costing me nothing for the repairs. In fact, I will end up with a model year newer vehicle for the price of a tune

Edited May 15, 2016 by JacobC1983

Badass69 · May 15, 2016

And nothing for your lost time... I have had mine for 20000 miles of driving and never seen the dealership once since I bought it. I would much prefer that. .. and warranty is irrelevant. I don't know why you care about my warranty so much lol... you honestly could have it if you think it will help your truck for all I care about it.

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Edited May 15, 2016 by 1994Vmax

Sir Dan · May 15, 2016

For what it's worth, the diablo tuner I used doesn't even support the 8 speed yet. I only used it to switch OFF the afm in the ecm (engine cntl module) so no tune in the tranny.