Rear wheel bearing symptoms

[Truck Norris]

When riding my atc 185s the left rear wheel kind of wobbels side to side as it spins. Is this due to a bad wheel bearing? And if so how urgent is it to replace it? In other words would it be dangerous or damaging to ride it for a while with bad bearings?

[wonderboy]

The bearings really aren't wheel bearings... they are axle bearings. They support the solid rear axle in the center. The wheels are just hard mounted on the hubs, which are hard mounted on the axle.

Here is what you can do: put the machine up on a block under the frame (do what you can to get the rear wheels off the ground). Now, try and wiggle the rear wheel that seems to wobble. Is it tight? If not, check the lugnuts and the center hub nut for tightness. If the wheel isn't loose on the axle, try to wiggle the entire axle relative to the frame. If you have bad bearings, this is when you'll notice it.

If everything is tight, then you may just have a bent wheel. If the other wheel doesn't seem to wiggle, just swap wheels left for right and see if the wobble follows the wheel.

Bad bearings could eventually chew up other parts, so it would be best not to ride too much on bad bearings. However, if all you have is a bent wheel, it isn't too big of a deal unless it is very bent and causing a lot of shake in the machine.

[Jmoozy27]

It could also be a bent axle. If all of the above tests come back good, and symptoms still exist. Look to the axle.

[Truck Norris]

Thanks guys ill lift it up right now and see what i find

[JustEnough]

I had this symptom on my 86 125M yesterday. I took the hub off of the axle and wire brushed a lot of black corrosion dust off of the axle spines and hub splines. The axle splines still looked new with the "gold anodizing" still there so I suspect that the hub is a softer metal and had worn because of the axle nut tightness was not being maintained. I was really getting depressed because the replacement hubs I had on hand had smaller lug studs, but the spacing looked right, 144mm? I finally tried a washer with a bigger inside diameter which allowed the axle nut to push the hub harder down the axle and the hub stopped moving. I suspect I pushed the hub a little further into the axle which allowed the hub to find the last bit of hub spline that is not destroyed and it is just a matter of time before that is ruined too.