TH350 stuck in high gear!

[Tom Goldman]

Pull the valve body down and check the case with a straight edge to make sure the case is flat. ....any distortion can cause leakage across the channels. ..............It is more likely that you have a pump issue , since the problem has ocoured with two different valve bodies......internal leakage in the pump from the foward clutch passage to the direct passage will give you high gear. .....Reverse will function normally because the foward clutches are turned off and the direct clutch is applied. ........I'd find someone who is familiar with performance 350's and have them take a look at it,and spend the time with your kid!.....Tom

[buzzinhalfdozen]

I agree you must have an unintended pressure leak, 2 most likely spots are the Valve body area or the frt. pump gasket area. A full manual valve body would not cause this issue unless there were a crack or porosity, since you've changed it you can rule that out. I would do as Tom suggested and have someone familiar with these trans. look at it, may save you money in the long run. Joe

[HotRodGMC68]

Thanks a bunch guys! The first chance I get I'll dig into it and find out what's going on! And don't worry Tom.. I plan on spending as much time with my little girl as I can!