Motorcycle Repair: Transmission Leak, custom chopper, transmission leak

Question
I have a custom chopper with a 80ci evo motor and a Spyke 6-speed transmission. It has a 3" open primary. What is the most common cause of fluid coming out around the shaft of the tranny? The shaft comes out the left side of the tranny. The gear for the chain and the back of the open primary attach to it. How hard is it to fix myself? Thanks for any input. Jason.

Answer
There are two seals on the that side of the trans. The main seal and the seal inside 6th gear on the end. You would have to pull all the components on that side to get to either one. the main seal is pretty easy to replace, the other one however is tough. You would have to have a race puller to get the race off before pulling the seal.
Good luck and happy riding
Mike