4l60e tranny

RICK74631

MEMBER
1960 CHEVROLET SILVERADO

Well am back again with tranny not working still not shifting right I unplug the tranny and took it out for a test drive and it ran the same it even shift one time with the tranny unplug does this mean I need it rebuilt or is some thing stuck open I had it hook up on a computer it said shift solenoid not working right put new ones in still the same new valve body new wire harness for gm93 and up thats what he said any way I have 1996 chevy ext cab silverado new gaskets for the valve body and spacer plate this is a real pain all gears work great I been drive around in second because drive and 3 does not shift right you take of is shift fine the first shift when you hit 20 miles an hour starts to shifts it just rebs up and win you stop it shifts back down maybe new bands am lost it did shift when the new parts were put on for a block

1 Reply

CHEVY22

MECHANIC
1,375 POSTS

I hope im not going to confuse this post but

there is a tsb out for a 3-4 shift failure, if I remember right it states if the transmission does not shift from 3-4 or has a bad slip there is an internal pcm ground fault, I fixed one a couple of years ago the same way, overhauled it and it had the same problem it did when it came in, I checked the gm si system found the tsb and the harness was 20 bucks and it took about 20 minutes to fix, and I had to laugh there was about 20 of us in the dealer and no one could get it, but this was the fix for that unit, hope it helps

jim