Velvet drive stuck in gear

Greetings all, I had an intermittent fluid leak from my Borg Warner 71c vee drive. I had to remove engine from boat in order to remove transmission. The likely cause of the leak was the front oil seal. I removed the oil pump cover and replaced the seal and reassembled the cover. The gearbox was in neutral prior to disassembly, when I put it back together, it now appears to be in gear as the input spline will not turn. Do l need to fill with fluid and pressurise the transmission to release clutch? If so, how do l do this?
Many thanks Rammy.

 

The clutches are spring loaded on the "normally open" position. Most probably the pump is stuck if it was turning before you changed the seal.

 

Thanks for your response gonzo, what I don't understand is how just removing a cover and pressing in a new seal has affected the free movement of the input spline. Before I removed cover, I remember thinking how silky the splines rotation was. Have you any idea on how to free a stuck pump? I have studied the diagrams from the manual and everything seems correct.

 

The seal may be too far in and hitting the gear in the pump. Loosening the cover will show if that is the problem.

 

Thanks for the tip gonzo. Took the cover off to have a look, spline is still solid so am guessing transmission is in gear? Baffled by this one.