I have a question right off the bat. I have a 98 GMC Sierra 1 ton with a 454 and the water pump was going out. Just before I replaced the water pump the transmission stopped going into overdrive. All other gears seem to be fine. I was told that the water pump could effect the transmission and fixing the water pump would fix the transmission. The water pump is replaced and I still have the transmission problem and can't figure it out. Any suggestions before I end up going to the transmission repair shop. Any help would be appreciated. Thank you.

No suggestions, but I'm sure someone will chime in with some thoughts. You might want to put up a post in the engine & drivetrain forum to help you out.

Oh, welcome!

Welcome to the board from South Mississippi.:D :agree: Check the Engine and Drivetrain board.

:agree: also and welcome from Cailifronia.