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Chevy 4L80E Transmission Pressure setting

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Moderators: mikel, 06MonteSS

Posts: 3
I've just put the 87 Tune on my 02 Avalanche 2500. It has the 4L80E Transmission, it shifts a bit hard like I'm trying to chirp my tires. I went into custom settings and changed the partial throttle shift pressure down to lowest setting -25 and it didn't change anything. Am I doing something wrong? I'd like to soften the shift up just a little bit. Awful heavy truck and I don't want to break anything. The transmission had a full rebuild about a year ago.


Posts: 54709
Location: DiabloSport World Headquarters

Im guessing it was rebuilt a bit better than stock to add some mechanical line pressure?
Maybe a shift kit? Valve body mod?
Mike Litsch
Powerteq Customer Service Manager
Diablo Tech support by phone:
M-F 8:00 AM to 5:00 PM EST

Posts: 3
No its a totally stock rebuild, the original transmission I had to drive 500 miles pouring in transmission fluid as fast as it squirted out to get it home to fix the leak. It lasted about 6 months before it quit, that when i had it rebuilt. With the stock tune you cant feel it shifting at all, really smooth.

Posts: 4
I'm in a similar position with the shifting, except no rebuild, still original trans (I believe) and 91 octane. I tried playing with the shift time with little success. It's my daily and I don't want to have to do a rebuild if I don't need to. 220k miles...
Although, when I do give it everything, that quick, hard shift is beautiful.
2002 avalanche 2500 8.1L cold air intake, cat back exhaust, I3 tuner, 31.5"general grabbers, 17" XD wheels

Posts: 3
Same here, I paid a lot for the nice transmission rebuild, not worth it for the chirping of the big tires, haha.

Posts: 6
Hey, guys...

I guessing I going to run into this as soon as I get my T2 EX working right. I was wondering if anyone has found a solution for this problem?

Posts: 17505
Location: CT

lower the shift pressure by -20%, and turn the torque management ON/Enabled...
06MonteSS / DiabLew Tune
2014 Camaro SS - 2SS, RS pkg., short-throw shifter, NPP perf. exhaust, BMR strut-tower brace, Cold Air Inductions cold air intake -- -- --

Posts: 6
06MonteSS wrote:
lower the shift pressure by -20%, and turn the torque management ON/Enabled...

Thank you, I let you know when I finally make it to that point, how it worked out.

Posts: 1
I have the t2 but i Wish i would have found this sooner. But rear seal is what happened to me and my dumbass listened to master mechanic and used the black silicone to seal the "rear housing" brand new bushing and whatnot. But now something else gave and my truck is rotting in drive way.

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