I have (2) 2003 Honda TRX 90's. One of them had a grinding noise and the chain would get extremely tight and then loose when the tires rolled. I inspected the rear axle and found that the bearing on the chain side was all torn up. I removed the rear tires, brakes and axle to get to the bearings and removed what was left of the bearing. My question is this, I have new bearings and seals on the way but I have found conflicting information about the installation of the bearings, do I install the bearings with both side covers in place or do i remove the side cover of the bearing that faces inward. There is not a grease port on the section between the bearings so i think I should leave the covers in place. Please let me know what is proper for this repair. Thanks in advance.

I have worked on motorcycles since 1967 and was around when the ATC90 was introduced.

The factory installs bearings that are open on both sides due to cost (open bearings are cheaper) - Polaris uses open bearings, but does have a grease fitting on the carrier, the only problem is that owners over grease the carriers damaging the seals and then pressure wash them forcing water into the bearing; the bearings fail prematurely due to rust - I always use bearings that are sealed on both sides (those are not just covers, they are seals) (bearings are also produced with "shields" that are metal, removable and allows the bearing to be lubricated without removal of the shield, but does nothing to seal out water and dirt) - it's your option, leave the seals on, remove the inner ones or remove both - the bearings will last approximately the same amount of time regardless. I just leave the seals on which prevents dirt from inside the carrier from getting into the bearing.

When you install the bearings, only drive on the outer race to install them - hitting the inner race will damage the bearing and shorten its life.