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2020 SLT SIERRA TRANSMISSION PROBLEMS!

Jake H.
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Jake H. New Member

Jake H.

Posted
Posted

Just wondering if others are having similar problems.

I have a 2020 Sierra SLT with the 10 speed transmission, truck has about 2500 miles on it.

Recently it started hard shifting at low speeds into gears.  It threw a check engine light and go so bad that it was banging in and out of gear from Park to Reverse when I shifted.

I took it to my local dealer, they kept it 2 nights and apparently called in and reprogrammed it and did a transmission relearn and gave it back to me.  They said the oil wasn't burnt so 

they were told not to change it.  Within 2 hours of picking it up it was starting to hard shift on me again, although less extreme.  

I just went out to my driveway to pull it in the garage.  When I put it in drive it banged around a bit and appears to be in 5th or 6th gear....very lethargic and you have to give it quite a bit 

of gas to get it in the garage.  Obviously frustrated with these problems on a like new truck...just curious if others have seen this?

  • 4 months later...
Bobby302 New Member

Bobby302

Posted
Posted (edited)

I feel bad 4 the problem that u having JAKE H. I only had my truck for 3 weeks now 800 miles On it and it has developed a kick every time I come to a complete stop. I’m so frustrated with GM garbage transmissions. 

Edited by Bobby302
bjr2020 6.2 Enthusiast

bjr2020 6.2

Posted
Posted

My trailboss custom 6.2 10 speed has 2500 miles been shifting smooth and feels better then the previous 8 speed I had but it seems to hang in gear when you like get on it to pass someone and let off it doesn’t shift back up afterwards very quickly it hangs in the rpms till you feather back into the throttle alil it seems. Dunno ?‍♂️ maybe this is normal with these tranny’s? 

Vigilante375 Enthusiast

Vigilante375

Posted
Posted

My 2018 ZL1 has the 10 speed ans these cars are known to have a 3rd to 4th and 4th to 3rd shift issue. All other gears shift smoothly except these 2.

 

GM hasn't really addressed it and we just deal with it. Other than that, it doesn't hang in the rpms, unless you've got it in performance mode, much when driving normal.

 

My 8spd in the Silverado did do the kick into 1st or whatever it's considered when coming to a stop but hasn't done so for a long time now. 

 

The 8spd is garbage but I enjoy my 10spd in my ZL1.

bjr2020 6.2 Enthusiast

bjr2020 6.2

Posted
Posted

Yea I should post a video of the hanging I’m talking about maybe all the 6.2 trail boss’s do it? There no where to adjust diff tranny modes on mine either just tow/haul. I see the other trucks have diff modes you can scroll through. Other then trannys been considerably better then my previous 8 speed.

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