Lubricate front wheel bearings
 

I have a 1991 420 SEL -- 75,000 miles -- and I would like to clean and regrease my front wheel bearings. I do not possess the specialized tool for removing the wheel hubs. Is the job anything similar to my old Volkswagen or my Volvo 740?? I don't want to risk opening a can of worms here. Any advice would be appreciated.....

Bob Irving
Charlotte, NC
(704)882-2272
rpiflying@msn.com

Be precise in using the correct amount of lubricant for the job (usually measured in grams). Too little or too much means a hot bearing.

You can't go wrong by using the grease from the MB parts counter. It comes in a tube and is a translucent looking goo. It works very well, dealing with the disc brake heat better than the standard stuff from the auto parts store.

Have a great day,

You don't need special tools to remove the hub. The manual calls for a dial gauge to set free play, but many folks do it by feel.

Sixto
91 300SE
87 300SDL
81 300SD

Some time ago, Benzmac said that zero play and zero pre-load was the rule. You don't need a dial gauge to come up with that.

Regreasing wheel bearings
 

Thanks so much to all who sent me replies to my inquiry. Very helpful and interesting.

Bob Irving

Bob,
Front wheel bearings on a rear wheel driven car are front wheel bearings. If you've done em before and you know what you are doing, go for it. If you don't understand wheel bearings, please leave them alone. You could kill someone. I hope you understand what I'm saying.

Thank you,
Peter

Actually, since the middle '80s, some manufacturers
 

have switched their rear-drive cars over to FWD type sealed ball bearings for reduced rolling resistance, but if you had such a machine, you'd know that they can't be serviced, only replaced.

Autozen is right, though -- way back in '69, Porsche changed their service philosophy to eliminate scheduled wheel bearing repackings (except when the hubs had to be taken apart for other reasons, such as brake work) on the grounds that almost all the failures they had encountered came from botched repacking jobs -- usually dirt -- rather than dry bearings which had not been touched since they left the factory.