8 Speed Cold Shifts/Morning Bumps? 5.3L

[mookdoc6]

Who has the annoying cold shift 1-2 in the morning or after setting for few hours and goes away after Trans Temp warms up? What have you done to Fix/Repair the issue? Programming etc. Or is it the FACTS OF LIFE WITH THIS 8SPEED?

[gary.smedley]

I literally just got mine back from GMC today. There is a bulletin out for this issue. They re-flashed and did something else. I'll report back tomorrow morning after my sim.

 

 

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[mookdoc6]

I literally just got mine back from GMC today. There is a bulletin out for this issue. They re-flashed and did something else. I'll report back tomorrow morning after my sim.

 

 

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Thanks Gary! I know you got yours around the same time as mine......I will pick mine up tomorrow and I was told that mine did not need the update but they did something else? I guess we will compare and see won't we...I was also told that the bump on 1-2 is normal and the pressure is building? It's just annoying.....

[mookdoc6]

Are you back in the states now? Hope so as the Crazy's of the world are going to be put down. Some dogs need to be put down brother!

[gary.smedley]

Thanks Gary! I know you got yours around the same time as mine......I will pick mine up tomorrow and I was told that mine did not need the update but they did something else? I guess we will compare and see won't we...I was also told that the bump on 1-2 is normal and the pressure is building? It's just annoying.....

Ok. So I know they said the rough shifts after cold start normal but this morning it did feel smoother. It's been sitting still since 0530 and I'm about to leave work. Hopefully I get the same result. Also, the entire drive here the up/down shifts felt better. I even did a hard braking at a red light, which gave me issues in the past.

 

 

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[gary.smedley]

Smooth again.

 

 

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[mookdoc6]

Smooth again.

 

 

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Gary, when you get time tell me the work they did! Thanks!

[gary.smedley]

Gary, when you get time tell me the work they did! Thanks!

Ok. So they said they "re-flashed the tranny module and did a "fast" re-learn"

 

 

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[Lgetz]

Gary did they also flush and refill transmission with synthetic fluid? This was the last thing they did on my truck and has been good since. Do have the 6.2 though not sure if that applies to 8 speed 5.3 as well.

 

Nevermind I just read title of post. ?