Installing new crank case bearings (2001 KX500)

[barryadam]

Any advice on pressing in new bearings into the cases?

I'm in the process of replacing the cases on the '01 KX500 (drain plug repair) with some nice new ones.

On disassembly of the old cases, I see the crank seals have to be installed from the inside, before the bearings are installed. In addition, the main bearings are seated in a cast iron insert in the case.

I've only done this procedure once before, and it was a small motor with no cast iron. The seals went in from the outside, so I could heat the cases in the oven/freeze the bearings, and assemble, THEN put in the seal. Then by freezing the crank assembly, I could install the crank and assemble the case halves. Obviously, I can't follow that procedure here.

Also, the clutch actuator bearings (2) look like a bit of a challenge to install correctly.

Anyone done these specific bearings/seals sucessfully on this application (KX500)? Got any advice or special tools?

Barry

 

[nickyd]

I'd probably put the seal in - freeze the bearing. Put a slug of aluminum over the case from the inside (covering the seal but laying on the case - not the seal) and heat the slug with torch - the heat will transfer to the case and probably give you enough clearance to drop the seal in. I also have a press in my shop and if the bearing didn't drop right in, I'd press it in place.

 

[barryadam]

Thanks. I like the idea of protecting the rubber seal from the torch (do you smell something burning....?)

I'll have to get some press tools made to support the case properly and press on the outter race.

If I measure the interferance fit, I can calculate the thermal conditions needed to make the dimensions work.

Barry

 

[nickyd]

do you have a press? I have a 20 ton - the bearings usually don't take much pressure to get into place - I use a large socket or even the old bearing to press the new in.

 

[barryadam]

Will ball bearings and cranks/crank assemblies handle cryogenic temps?

I have access to:
liquid CO2 (-109 F/-78 C), or
liquid Nitrogen (-320 F/-196 C), or
liquid Argon (-302 F/-186 C)

This would make press fitting less stressful. I could heat the cases with the seals to a max temp of just under 200 F (to protect the seal materials). And of course, there's always the freezer (+32 F/ 0 C).

Barry