1st to 2nd rough shift

[BigredGMC]

Hi I have a 2019 GMC Sierra Elevation with the 8 speed, and was wondering if the 1st to 2nd rough shift is normal for this transmission?  Sometimes it shifts without noticing anything and sometimes it slams into 2nd. Been to dealership like 5 times, last time they updated the program so 2nd to 1st rough shift was fixed but still have intermittent 1st to 2nd. Is this normal or should keep going back?  I test drove an 2020 8 speed RAM and that was smooth like butter. Again thanks for replies .

 

[UGADawgs]

known issue for cold vehicles. let it warm up first or hold pedal down lightly until in 2nd after initial go.

[BigredGMC]

It does it cold or hot. Sometimes worse when feathering the throttle.

[UGADawgs]

4 minutes ago, BigredGMC said:

It does it cold or hot. Sometimes worse when feathering the throttle.

Have them change the fluid

[BigredGMC]

I tried, they don't want to do it. I guess I have to go back again.

[jlong1984]

37 minutes ago, BigredGMC said:

It does it cold or hot. Sometimes worse when feathering the throttle.

Mine only has the harsh 1-2 shift when the transmission is cold and I go straight from reverse to drive. If I give it a few seconds before I shift from reverse to drive I don't get a harsh shift. 

 

This seems to be the general consensus among forum members with the 8L90. 

[BigredGMC]

I guess I f it does no damage, if they do nothing I'll live with it. After highway driving I get the rough shift for about a mile or 2.  When cold it shifts smoothly.  Weird transmission.

[bmoney5813]

I had this issue. The thing that consistently worked for me was a deliberate pause after shifting it into gear. Mine only occurred first shift of the day so if yours does it more often it may or may not help. As others have said, the fluid change may be needed. 

[Dunn]

mine had a rough 1st to 2nd if I rushed it......let it warm up and be smooth especially first drive of the day, after that was pretty much smooth as butter.....right before I sold it I noticed a few more clunky shifts that weren't normal but who knows, could have been mental thing....

[topgear1224]

It does it cold or hot. Sometimes worse when feathering the throttle.

Known issue / behavior with the 8-speed.

GM has informed dealers and has explicitly stated they are not to change fluid under their customer satisfaction clause. (GM won't pay for it)

The best advice I can give you is find the transmission guy at the dealer.

He can perform a stationary relearn. if that doesn't work he'll likely have to tear the transmission apart and use a micrometer to make sure the clutches are set properly.

At my local dealer here in Alaska the transmission guy (joined GM in 2000) says that every single one that didn't get better with a stationary relearn he had to tear it apart and he found that the tolerances would not correct in the clutch packs from the factory.

I returned my dream truck over the problem.

Went from a 2019 LTZ tech package to a GMC X31 Elevation. Cost me exactly the same amount of money [emoji35][emoji35][emoji35].

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[topgear1224]

Might want to try to add your name to the class action lawsuit, it's unlikely you'll get much. But it should at least help with the resale value if they win.

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[BigredGMC]

Thanks for all the replies. Now for a couple of days while stopped at a red light my engine stumbles and feels like it's about to stall.  It happens about 20 seconds while stopped already.  Does not always do it but has done it twice in 3 days.

[topgear1224]

Thanks for all the replies. Now for a couple of days while stopped at a red light my engine stumbles and feels like it's about to stall.  It happens about 20 seconds while stopped already.  Does not always do it but has done it twice in 3 days.

It's the stupid transmission tuning. Next time it tries to do it push the brake pedal to the floor. If it stops shuttering it's the transmission tuning.

Do the RPMs drop?

Even on my 10-speed when slowing to a stop and dragging the brake pedal, the transmission is actually fighting the brakes. Every once in awhile it gets so bad that I don't know if I can stop in time. (Feels like it's trying to accelerate)

I just started throwing it into neutral when coming to a stop when it starts behaving badly.

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[BigredGMC]

It stops nicely, no shudder only after about 10-20 seconds it feels as thou it's about to stall.  And yes the RPM's drop during that 10-20 seconds.  It never did it before. I'm afraid to take it up north for the long weekend, don't want to be stranded.

[topgear1224]

It stops nicely, no shudder only after about 10-20 seconds it feels as thou it's about to stall.  And yes the RPM's drop during that 10-20 seconds.  It never did it before. I'm afraid to take it up north for the long weekend, don't want to be stranded.

How low? And do you have the 2.7 or the 5.3?

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