94 SL320


Short form question:

Can dropping a car from a stand onto the floor with the tire removed damage the center bearing? (Not the wheel bearing.)


At first I thought no. Then I talked to a Ford guy and we could imagine the drop flexing the drive shaft in an odd way that could have damaged the center bearing.

Why I think it cant:

The rear differential would absorb most if not all impact from dropping the car.

Dropping from a short distance is equal, at least as far as the rear differential and drive train are concerned, is equal to a hitting a pot hole.

Why it might:

If the differential itself hit the ground it might cause an abnormal flex in the drive shaft.


Long form:

Wheel lug would not come off. Shop heated and torched the wheel. Finally it came off. The wheel was utterly destroyed.

Put the spare on and new tire.

The next day after getting the car back it seemed to be driving fine. At about 60 mph I started hearing the noise you hear when a playing card is in bicycle spokes.

There had been zero noise of this sort at all previous to this day.

I pulled over and pulled off the back wheels. Nothing apparent from the top.

It only makes the noise when rolling and braking has no effect on it and you can feel the vibration when you put your hand on the gear shift.

Took it back to shop and guy says its the center bearing. Put it on lift and ran the car. Could hear what appeared to be something hitting the heat shield right where the center bearing is.


At home I climbed under I saw that the shield of the brake housing was dented on the bottom. A spot which can not be dented with the wheel on.


I was getting ready to take it in for the $800 center bearing replacement.

Assume it was dropped. Could that have taken out the center bearing?


Discussion posted on car talk:

Frozen lug to busted bearing?? Is it possible? Or just lucky? - Car Talk

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94 SL320
71 porsche 911S


www.KriminalDefense.com

That seems a bit strange to me.

If you didn't see the people working on the car then it makes it difficult to guess if the car was actually dropped onto something which damaged the centre bearing or not. Dropping the car onto something sticking up which then damages the centre bearing area seems to me to be the most logical explanation for the damage you describe.

Are you sure that the damage you hear is due to the damage you can see? It might sound a bit daft - but when they were damaging the wheel to remove the lug bolt did they happen to have the automatic transmission in park and perhaps a clamp on the other wheel? {I don't quite know the specifics of how the differential on your car would behave to lots of torque being applied to one wheel}

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I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

Extremely unlikely. Also not really clear that anyone dropped the car - the brake rotor edge should show some signs of impact.

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Prost!

The rear diff is stationary on these cars so not much moves around more than 3/8". Also, the center bearing is mounted in rubber to take up any vibration and the drive shaft telescopes.

"Dropping " the car won't damage the center bearing unless they folded the car in half, Ford guy knows nothing about cars / bearings/ physics / engineering.

I'd have a look at the new lug bolts in case they are too long rubbing the parking brake shoes / hardware. Tire balance could be an issue, if the car was picked up on a single post lift it might have bent the drive shaft but that would be difficult to do. ( the old gas station style where a large hydraulic cylinder comes up from the floor and the lift plate has 4 arms. )

Have a look at the rubber drive discs, they don't age well and can come apart. Some have has the air bags pop when the drive shaft becomes dislodged.

Destroying a wheel for a frozen lug is pretty pathetic, you obviously had it at the wrong shop to start with. About 50% of the time I can walk up to one with hand tools and have a seized / broken lug out in 30 seconds. The truly stubborn ones get drilled out, typically without even a scratch to the wheel.

Add in the fact that they dropped the car on the backing plate makes me have serious doubts that they have any business working on cars at all. That said I highly doubt there is any correlation to a failed center carrier bearing and botched wheel repair.

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The brake shield is dented. This is why I believe it was dropped.

The vast majority agree that assuming it was dropped it would not cause a center bearing to go out.


It was lifted on a four point lift when I was there later about the center bearing sound.

When I was there and they were trying to get the wheel off Im fairly certain it was not on a lift but one wheel was jacked up.


I dont know if there was clamp on the other wheel. Nor whether it was in park. I assume it was in park at the very least. But I didnt see.



The odds. One day after wheel issue I get a bad center bearing.

Theres no question it has the miles to justify a bad center bearing. Over 150k easy. I drive her like a cream puff though.

Well time to just bite the ball bearing and take it in.

__________________
94 SL320
71 porsche 911S


www.KriminalDefense.com