I have a '91 Big Bear 4x4 350 SE. I bought it used last spring. Recently I noticed that there was some play in the back wheels. I suspected the bearings. I promptly lifted the quad and took out the axle to change the two bearings. I was horrified at what I saw. The bearings were so rusted that they almost came apart in my hands.
What was worse was that the splines on the shaft, where it seats in the diff were no longer shaped correctly. They were pointed instead of the usual spline shape. This is no doubt because of the bad bearings.

I called for new one ($CAN 500.00). Looked for a used one, forget it. There are few and far between.

I was told by one shop that they can weld the teeth on the spline and then machine new teeth. Has anyone heard of this? Is It OK. The price is better ($ CAN 200.00) but would hate to try it and six months down scrap the it and the new bearings.

Any opinion would be appreciated.

ALSO : My two cents worth.

This is my first ATV and still cannot believe that the ONLY way to grease these damn bearings is to take out the shaft to grease them. The original bearings I took out, or so I assume they are original, are closed on the outward face but open on the inward side. Didn't anyone have the bright idea to put zerts so that grease could be applied? This would help.

 

A good machine shop should be able to do your metal work and get it back to specs. I wouldn't be afraid to do that as long as they'll give you a guarantee that it will be up to specs.

Crashgordon

 

I dont know anything about the major problem that you have. However, I havefallow up on your note. The Big Bear 400's which replace the 350's do have grease nipples. I am sorry this does not help your problem but for people looking for used Big Bears I would go with the 400 because of small improvements like these that are a big deal down the road.

Gern