Hi all,

The front right wheel bearing on my '87 300D was loose last month and it was tightened by a reputable MB only shop in the area. They said the grease looked good and only tightened the bearing. Grease on the left side was good, too. (I had a problem with a tie rod that was probably putting a lot of extra forces on that wheel - toe was WAY out - so I think this is why that side had a problem. A few weeks before that there was no loosenes in the bearings).

Last night I was checking my wheels and the front right wheel bearing is loose again. The left side wheel can be hand spun VERY fast, but the right side requires more effort and does not spin as fast. I am wondering if I should retighten or replace the wheel bearings?

If I must replace, should I buy only the outer or inner bearing, or the entire kit? Is NTN better than Febi? The dust caps are in great shape and it looks like save some money. Does it make sense to only replace one side, or should I do both at the same time? Anybody now if there is a "Set" number I can buy locally? For example, a 380SE takes "Set 3" and "Set 5".

Thanks for your time,

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Brian Toscano

Check to see if your brakes are binding/not releasing fully requiring you to use more force to rotate the wheel.

I agree that the issue is probably drag from the brakes.

The looseness you mention doesn't sound right. You may want to check the following thread to see if any of it may help you:

Steering vibration comes and goes

Don't buy any bearings stamped "Made in China"!

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95 E320 Cabriolet, 159K

To properly test, you must remove the pads. If there is any roughness or noise from the bearings after adjusting for proper end-play, replace both inner and outer, including races and inner shaft seal, and perhaps the nut. Use the correct amount of approved grease.

Steve

Bearing 'looseness' would not cause binding. Quite the opposite. Binding would imply that the preload is too tight, or the bearings are worn to the point where they are not turning freely. In the worn case, you would probably hear a 'growling' noise at speed, which might come and go when you turn one way or the other.

It is also possible that the shop set the right side correctly, and the left side spins more freely because it was not adjusted. Check that one for excess play.

As others have said, it is normal for the brakes to drag somewhat until there has been enough rotation to push them away fully. Severe brake drag (usually coupled with premature wear and often warped rotors) implies a problem. It is difficult to prove that a bearing is binding without removing the caliper. A bearing with too much preload will make the hub area of the wheel much hotter to the touch (than the other wheel) after a moderate to long drive, and it will eventually suffer premature failure. Of course, a dragging brake will have the same effect, so perhaps that is not useful in this case.

Either bearing brand is excellent. These things will last virtually forever if resealed and repacked every 100K miles or so. Both sets should be replaced at the same time. For the labor involved, it would be silly to do just one set. I have had very bad luck with the fit of the aftermarket grease caps. They are just a bit too large, and the process of forcing them on resulted in metal filings being shaved off the cap. Had to replace much of the grease to be safe. Very annoying. Save the original caps if possible.

Best of luck.

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1986 300E 5-Speed 240k mi.

Thanks for the replies. This morning, going down a curvy hilly road a deer dared in the front of the car making a rear mess. The wheel bearings are the least of the problems for the moment.

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Brian Toscano