Like the title says, my 700r4 won't upshift past second gear, governor gear is in good shape.. shift linkage isn't the issue.. any other ideas? I'm planning to rebuild it but I'd like to figure out what is causing the actual problem so I don't have the same problem after putting it back togather..

Need some clarification here.

When you say it won't shift past 2nd gear, does it just stay in second or does it feel like neutral when it shifts into 3rd?

Any recent modifications like a shift kit?

What's the TV cable connected to at the throttle body? Stock or aftermarket FI/Carb/TBI?

Was it shifting normally before?

I would think shift solenoid without knowing anything else.

There are no shift solenoids in a 700R4. Just one solenoid for TCC lock up.

Depends on the year

They probably figured out whatever the problem was 10 Years ago.

No it doesn't depend on the year. The 700R4 / 4L60 transmission doesn't have shift solenoids.