4L60E Manual Upshifts Only Hot
I have a problem with a friend's tranny. I helped him out with it.
Fresh rebuild (1995 TransAm) with all new clutches, steels, bonded pistons.
It had a Transgo shift kit already and everything put back as per Transgo instruction sheets.
After a drive around the block and stopping at the lights, it won't automatically upshift anymore.
It will upshift fine manually.