LS1Silverado05

iTrader: (41)

Ok here is the issue. I cant get my car to make the 2-3 shift at WOT without banging the limiter. The shift is commanded at 6400rpms, and the limiter is at 6800, plenty of room I would think. The MPH that needs to be met is well under what MPH I am at when the shift is commanded. Line psi is up. Fluid looks and smells perfect.

Sometimes....if I let it hit 2nd...and I rollllllll it into the floor, it will make the shift (and it will be nice and firm when it does).....HOWEVER....If I launch from a stop, and it hits 2nd and then goes for 3rd...no dice. Any ideas? Im out of them...I really dont want to pull the tranny if I dont have to!

performabuilt

iTrader: (25)

Lower the shift RPM a little more the 2-3 takes a little longer to make hydraulically

LS1Silverado05

iTrader: (41)

Even more than a 400rpm gap? How far down should I go with it before it is decidedly a trans issue?...

performabuilt

iTrader: (25)

i would give it 600 to 800 because of your stall I have heard of guys having to command shift as low as 5200 to make 6200

LS1Silverado05

iTrader: (41)

Ok, Ill give her a shot. Thanks.

LS1Silverado05

iTrader: (41)

Well, we definately are past the MPH to shift, and we set the shift point all the way down to 5,500 and we still will run to the 6,800 limiter! We even lowered the MPH in the TPS% files in case for some reason the car wasnt seeing WOT and wasnt meeting the part throttle MPH.

I guess the tranny is done, but I dont understand why it will shift perfect under normal driving or even from a 2nd gear punch it will hit 3rd. But from a solid stop, it will not let it hit 3rd. When it DOES hit 3rd it feels fine, nice and firm positive shift.

therobman

iTrader: (39)

from a stop put it in 1 and manually shift it up see if that works

20lbbooster

iTrader: (3)

check your speed sensor. I had the same exact problem. Changed out the speed sensor (Gilbert & crew at ACE) and problem was solved. It took a long time to figure it out! Now its a champ!

performabuilt

iTrader: (25)

You could check the speed sensor , Also you might consider just changing the 2-3 shift solenoid. Also in tuning have you raised the line presure? excessive line presure could cause solenoid flooding and not allow the return of the 2-3 valve on release at WOT

20lbbooster

iTrader: (3)

definitely take a look at your speed sensor. seems to be a fairly common issue that gets overlooked. check to see if your rpms do anything funny when you are driving the car, espicially when it downshifts. After some transmission tuning, servo changing and whatnot it turned out to be that sensor.