hey guys im trying to help a buddy of mine out who just bought a 99 z28.
the problem he is having is, that if you put it in D it will start off in 2nd and does not go into od. he can manually put it into 1st and shift it up but still doesnt go into od.
now the previous owner had the tranny rebuilt and said he had the trans rebuilt and a shift kit put in. then he replaced all the solenoids, wiring harness, and module and claims that all the trans needs is to be retuned. iv googled it and i have not seen anyone needing a retune after new solenoids. so if you guys have any insight, it would be greatly appreciated.

one other thing, the previous owner said he had it hooked to a computer and it showed it was shifting into od but wasnt physically doing it.

 

It could easily be that the shifts are not being commanded for one reason or another. Is the check engine light ? If so, it could be that it is in a limp mode whereby it will not upshift until that problem is resolved.

What is the fluid level and fluid condition?

If indeed someone installed a shift kit during a build then there could be many reasons for the symptoms. Get a scanner on it and see if it has codes, if so what are they. Write them down. Then clear the memory and go drive it. Se if the light comes back on immediately or not.... if it does not then watch the scanner for upshift commands.

If you don't have access to a scanner ask around for a shop that will diagnose it for you. Then, get back to us and we'll go from there.

 

it shifts from 2nd to 3rd just fine in drive. the fluid level is good and the fluid is good. i dont believe there is a check engine light on, but ill ask him.