Rebuilding the 400 trans

Hey gang,

The tranny saga continues. Looks like both the pinion and wheel gear for 4th gear ratio are toast (two really chipped teeth) to the point of nothing left. As well as a 5th wheel gear that has lug pockets damaged enough that it was abusing the 5th gear shift fork (trying to push it out of gear).

I'll say it again guys, CHECK YOUR TRANNIES OUT. I had no clue other than the slight oddity while driving on pavement. I would have never suspected a gear failure had I not listened closely. I did also notice once I benched the motor and slowly / quietly turned the output shaft, I could feel the roughness.


Looking for a neutral start switch block-off plate. My switch came off nicely but is brittle and cracking around the connector. Rather than replace it, I thought I could block it off easier.

Who makes one?

By the way, add another top end in perfect condition to the list of older YZ's. I really think for those of us not racing them (just in the woods) they really can go the distance without teardowns.



Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now