5.3 cutty

iTrader: (2)

jumped in the ls game and did a swap in my g body and had my tranny rebuilt and had some parts replaced beast sun shell,tci 2800 converter,zpac cluch kit and a hd2 shift kit.Trans runs fine just will not shift into 4th just holds 3rd like a 3 speed. has anyone had this problem ?? any advice will be helpful

mrvedit

If 1st, 2nd and 3rd are working fine then it is unlikely there is anything wrong with the internals of the trans. 4th gear is a combination of 2nd and 3rd gears. (3/4 clutch applied and band applied)

A bad shift solenoid A would prevent a shift into 4th gear, but it would also cause the trans to start in 2nd gear and not 1st. If you are sure you have 1st, 2nd and 3rd gear, it is unlikely to be a solenoid or electrical problem.

Most likely, something was assembled wrong in the servo. Start by making sure the 4th piston (outer most) was not installed upside down and that its seals are intact. The HD2 kit has you make some mods to the servo, double check them and all the seals.

Otherwise, the problem has to be in the valve body. Again double check the HD2 mods and make sure the separator plate gaskets are new or like-new.

All this assumes of course that the PCM's tune was not changed.

Please keep us posted.