rock7174

72' Chevelle with an LS3/4l80e swap. I've had Lorenz at LSX tune my Chevelle through data logging/email. I've always had an issue where the engine will just rev like the trans is slipping (past 3 years). Between 1st and 2nd, 2nd and 3rd. When I hammer down the rev isn't as bad. If I gradually give it gas it revs between the lower gears 1st-3rd. Doesn't do it off the line. So much so that I was convinced my used trans was all used up! I had monster transmission build a trans and provided a custom built converter (complete different than the one I had). Ran new lines and trans cooler. Same exact problem. Its driving me so mad that I've been debating selling it and I love the damn thing. Could it be in the tune? Trans tune more specifically? Probably need to take to a dyno tuner, but I want to make sure there isn't something else I'm overlooking. Not sure this is the correct place to post. HELP!!!!

G Atsma

Sounds like the tranny tune needs looking at.

rock7174

Thats what I figured. Just glad to have a little reinforcement before I drive to a tuner........speaking of a tuner......anyone know a tuner within a couple hours of southeastern Iowa? I'm around the Iowa City/Quad Cities area.

B52bombardier1

Whatever you do, don't sell it. You are so very close to getting it dialed in. How old and how many miles on your 4L80E? Does it throw any codes such as P1870 for transmission slipping?

Rick

LSX Power Tuning

iTrader: (4)

The last email we received in 2017 you said it was low on fluid and once you filled it back up it worked great. We will gladly fix it if its something in the tune, we didnt know there was an issue to fix though. Just sent you an email with a new channel config to log with.

rock7174

I’m sorry I did’t intend to make it sound like it was your fault Lorenz! I let it sit for a long time before replacing the new trans and just frustrated after getting a new one. Wasn’t sure if it was mechanical or tuning related. Thanks for the email, I’ll try it out and get back to you.

To the other reply, the trans is newly rebuilt. Less than 50 miles.

andy burdess

I’m in the Waterloo area and could do it for you. Pm for info

joecar

Install a 300 psi pressure gauge to the line tap on the side of the trans case. Place the gauge some place where you can observe it safely while you drive, you want to see what the gauge does when the engine free-revs in gear.

Check condition of fluid, does it show signs of slipping.

Remove pan and check filter for friction material.