3rd gear

My 1997 Tacoma started popping out of 3rd gear. Any ideas what it might be? In have the transmission out and dis-assembled.
Mike

 

Guessing this is a manual....

I had this happen in an old Subaru years ago.... started with 5th then 4th and so on. Turns out I had a slow leak in the gearbox and was running low on manual trans fluid (and eventually dry) and the gears were overheating, causing them to pop out. It went on long enough that it recked the transmission altogether.

Was there fluid in the gearbox before you took it apart? Might need a new 3rd gear either way