Wheel Bearings

What happens when wheel bearings fail?

front ? back ?
more rolling resistance…
over heat…
overheat and melt together , locking up…
come apart and wheel falls off…

more info

Failing bearings start by making noise, usually a roaring sound. At the same time they will run hot. Eventually, they will loosen up so the wheel or shaft is no longer held steady. Finally, the bearing fails completely and the wheel or shaft departs.

Ken’s got a pretty complete list there. If someone TOLD you your wheel bearings are about to fail and they should be changed. And you are trying to delay spending the money, don’t delay, fix it now because of the last 2 points Ken lists above. Your day can go from Just Great to Worst Ever in a very short time.

Why do you ask? Is there something we can help you with?

Just curious. Never had a problem myself but have always assumed that something catastrophic would happen.

Only if it is a catastrophic failure. A wear problem will let itself be known before things get, umm, explosive. I saw a catastrophic failure once. The owner simply ignored the growling and squealing of the wheel bearing until the excessive heat from the fricition caused the spindle to fracture, the spindle nut to come loose (never found), and tire, wheel and hub to come off as an assembly, dragging under the car by the brake hose.

Here is a tale of a wheel bearing going bad. A light truck had a front wheel bearing serviced. The axle nut was tightened according to the Factory Service Manual to 35 ft-lbs while spinning the hub and the cotter key was installed. The truck went 200 miles before the wheel was noted to be leaning substantially. On disassembly, the outer bearing axle race was welded to the spindle and the inner bearing, race, and grease seal remained trapped. The restoration involved replacing the entire knuckle on that side meaning the king pin and tie rod end had to be removed. .Also the inner and outer bearings; the inner and outer hub races; and the grease seal were replaced. In addition the truck was down away from base for 5 days.

The original servicer had not read the rest of the procedure in the FSM about backing off the axle nut; tightening it to 6 ft-lb; backing off one flat; and backing off till the cotter key could be installed.

So ends the tale of a 200 mile bearing failure/destruction.

I’ve heard a rotor that was held to the vehicle by the caliper only.

When my dad was alive, I had stopped to see what he was up to. He was as mad as a wet hen and working on my sisters car. A wheel bearing had gone bad and she ignored the noise and grinding and continued her trip home from a vacation three hours away.
Everything came off alright except for the inner bearing that was welded to the spindle. I found him sitting with three dulled up chisels and hammer in hand. He had blunted three chisels trying the get that bearing off.

I went home and got my dremmel and using a small cut off blade , was able to cut 3/4 way through the bearing and then split it with a chisel.