Bad Rear Wheel Bearing Yam Big Bear 400??

[Dave1]

I have a 2005 Yamaha Big Bear 400 4WD with manual transmission that has what appears to be a bad rear wheel bearing on the non-brake side.  I noticed the wheel was loose, shook it from side to side, found some slop, looked on the rear axle and could see the bearing has worn to the point the wheel hub is not perfectly centered on the axle.  Hopefully it has not ruined the bearing surface or axle.

I have never had to replace the bearing assembly.  How do I remove old bearing and replace with new bearing assembly?

Thanks for any information.

Dave 

[TRX450R_Racer]

I'm not familiar with utility quads, but I would guess it needs to be pounded out.

[crom A zone]

you need a  BFH or a press   but i prefer the BFH and a nice punch set.  they go  bad on my eiger witch is close set up to what u have   its not hard at all   just get a new dust seal   for it when u buy the bearing   any more ?  just post up and ask

[Dave1]

When I removed the rear wheel and hub, I discovered the hub was a splined assembly, and not a hub with inner/outer bearings.  The problem was that there was no cotter pin to lock the hub nut tight and keep it in place.  The nut had backed off a ways which allowed the hub to be loose and wobble on the splined axle.  That wobbling around did wear the splines significantly in both the hub and on the axle, but it did not appear to be terminal.

I used a small SS toothbrush and brushed and cleaned all of the rust and corrosion out of each part inside and out, reassembled using a good grade of marine wheel bearing grease on the splines, tighened the nut up, and placed a new heavy duty cotter pin.  Hopefully this will be the end of the story but I intend to keep an eye on it and see if it will remain tight.

Anyone else ever encountered this problem?

Dave
 

[Dave1]

No end to the story yet.

After cleaning it all up, reassembling and tightening, as described, I took it to the woods for a test ride.  Afterwards I found the wheel hub has loosened up again and the hub is again wobbling on the splined axle end.

Not sure, but guessing that I am going to have to replace either one or both the wheel hub and/or axle shaft.  To replace the axle shaft appears that it will be a major deal possibly having to dissassemble the entire rear end.  Not sure that replacing only the wheel hub with a new one will cure the problem.

Any good ATV mechanics out there?  I need some accurate guidance and advice.

Thank, Dave

[Dave1]

It seems this is a more common failure than I thought.  A friend of mine with a Kawasaki ATV has the same problem.

I found the axle for my Yam Big Bear 400 4WD ATV online for $237.  That is alot cheaper than the $378 I was quoted from a Yamaha shop here locally.

Now, if I can find a repair manual or similar that will walk me thru the steps to change the axle.

Anyone ever done this?

Dave