I have what appears to be a leaking gasket at the transmission trapdoor of my 1999 EVO engine/5speed tranny. The motor/tranny has 56,000 miles of troublefree operation and now this leak. I am told it is very rare for this gasket to leak and its a real job to replace. Local HD mechanics talk about removing everything just to get to this gasket coming from the primary side of the motor/tranny. Why cannot one access this gasket by disassembling from the tranny from the right side (remove exhaust first)?

thoughts?

 

The Mainshaft and Countershaft are a press fit into the ball bearings that are in the trap door. It is possible to remove the trap door and leave the shafts in the tranny, you need a special tool to push the shafts out of the bearings, and another tool to pull the shafts back into the bearings.

The bearings are cross loaded during the removal process, and must be replaced.

Normally the entire gearset and trapdoor are removed as one unit, this requires the entire primary drive, clutch, and drive pulley to be removed from the left side.

Are you sure it is the trap door gasket and not the clutch mechanism cover that goes onto the trap door?

 

Dan,

thanks for the reply and insight. My "wrench" decided to build a special "puller" and went at this job from the transmission trapdoor side of the bike. He removed the exhaust system and then "pulled" the trapdoor off, replaced the bad gasket (which indeed had failed)and then "pushed" the trapdoor back in place. He told me normally HD would go the route you outlined but he did this way to reduce amount of time to repair.
Now I do not question my "wrench" on his abilities as this fellow has build engines from the ground up, but I am a bit nervous about your comment about replacing the bearings. I know he did NOT replace those bearings.
Care to comment about his approach?

thanks

 

When the trap door is removed there is a cross load put on the ball bearings in the trap door, the manual says replace them.

I always have replaced any ball bearings that have been cross loaded. But I`m not a pro harley wrench,I`m a Jet Engine Mechanic (the bearings we work with are configured a little different, they can be removed without cross load).

I would bet that in reality there is not a lot of cross load on those bearings when removed and that very well may be the way most wrenches do the job.

Maybe some Pros can weigh in on this...