70 CHEVELLE SS

I installed a 4L80E in my Chevelle recently that was freshly built and used the Optishift management system. After I was done with the project I road tested the car but wasn’t happy with the soft shifting. I did a little research and decided to install a Transgo shift kit, the 4L80E-HD2. I followed the instruction exactly as described. I even drilled the separator plate the largest size of .120 to accommodate the stall converter. After this was done the road test showed that the 1-2 shift was slightly better but the other up shifts seemed to be the same. Does anybody know what the secret may be? I’m stumped and I even googled this with no real cure.

slow67

iTrader: (2)

Put a pressure gauge on it to see what line pressure is during shifts.

70 CHEVELLE SS

I live in Michigan and the roads didn't allow me many roadtests.Today was a day that I got a chance to drive the car and put some miles on. What I discovered was that under light throttle the car shifts fine, just not firm. While driving harder or WOT it shifts much firmer. So with that being said, I guess there isn't really a problem. I guess I'm just used to the old TH400 that shifted much firmer, even with light to moderate throttle.

slow67

iTrader: (2)

Then you should be able to modify it (or have it modified) in the tune.