I just rebuilt this ITR tranny. It had a sickly 3rd gear synchro. Now when I took it apart it shifted very smoothly on the bench. When I replaced the synchros I oiled everything pretty well...I thought, but the tranny is back in the car now and shifts really hard. I just filled it with oil(for now) and turned the motor by hand a few times, haven't started it. If I put it in gear, start it up(wheels lifted), and let the wheels just spin for awhile will it loosen the tranny up to where it was? I'm absolutely certain it went together right, I just didn't think it'd be so stiff. It's like Al Gore at a rock concert.

 

Only third gear?

 

Yeah that was the only one getting sickly. I never actually ran this tranny but the guy that sold it to me is a stand-up HTer and admitted it was just starting to grind 3rd at high RPMs. When I took it apart those were the only synchros that looked worn.