W123 leaking wheel bearing grease? - PeachParts Mercedes-Benz Forum

Jeremy5848 · #1 12-11-2007, 12:32 AM

For the last month or so I've noticed that both front wheels of the '85 seem to be getting especially dirty in the area of the hub (see photo). It looks like grease from the wheel bearing is leaking out and brake dust is collecting on it and making it more obvious. I usually keep the car cleaner than it now appears but we've had just enough rain to make washing the car impractical.

The wheel bearings have not been touched since I've had the car. They're not making any noise. I haven't yet jacked up the car to see whether the wheels will spin freely. The car has just under 230,000 miles total and I have no idea how old the wheel bearings are.

It seems as if the car is trying to tell me something but I don't understand (must be the German accent, hein?). If the bearings are getting hotter than they should be, that would cause the grease to flow, I suppose, and splash out of the bearing. If that is so, then it means I should pull the bearings out to clean and re-grease. Any other diagnoses or comments?

Jeremy

pawoSD · #2 12-11-2007, 12:41 AM

Mine look like that too, but when I take off the wheel....no signs of grease.

I have a theory that the airflow around the wheels concentrates the brake dust in such a way that it accumulates on that part of the wheel. Maybe a sort of air-cyclone?

#3 12-11-2007, 12:59 AM

If the "dust cover" over the nut is in place there shouldn't be any grease able to find it's way to your wheels. I also vote for brake dust and dirt.

Sbean · #4 12-11-2007, 03:09 AM

Grab the top of a front tire and push and pull side-to side to feel for looseness (clunking). Stop after driving a while and feel the hubs to see if one is hotter.
Is it on the sunny side? Jack up a front wheel off the ground and spin it to listen for roughness. Steve

MBeige · #5 12-11-2007, 03:22 AM

Mine does that, and coupled with the brake dust, that's a fairly common spot to collect brake dust. Another common spot for brake dust is the wheel lip rim, as well as the spot between that star cap and the wheel where it joins. Finally the third spot where brake dust likes to collect is at the sides of the spokes of these Bundts. PITA to clean each one but well worth it once it's nice and clean.

I know because I just washed my car and had to wipe that spot clean on both sides of the front wheels.

Pop the star cap out and see if there are any leaks. That's the surest way to find out, other than taking that wheel out of course.

t walgamuth · #6 12-11-2007, 07:04 AM

If you aren't sure when they have been packed, pack the front bearings with fresh grease. If you do that once every three or four years the bearings will last about forever.

Tom W

Dee8go · #7 12-11-2007, 08:13 AM

Quote:

Originally Posted by Sbean

Grab the top of a front tire and push and pull side-to side to feel for looseness (clunking). . . . Steve

If it's to this point, you'd be replacing the wheel bearing, wouldn't you?

bodyart27 · #8 12-11-2007, 10:02 AM

When I did front bearings I noticed that I had that exact problem for a couple of months and it stopped. I just pulled the weels, simple green degreaser the wheel and outside of the dust cap and cleaned everything up, and that was that - it stopped. I guess it was a little excess oozing from the dust cap.

vstech · #9 12-11-2007, 10:06 AM

you would be amazed at how tiny a gap can be "felt" this way. a small amount is acceptable, but any serious clunking, and you will certainly be changing at least the bearings!

t walgamuth · #10 12-11-2007, 10:16 AM

A small looseness will not ruin the bearings for a good while.

Tom W

Shawn D. · #11 12-11-2007, 01:08 PM

My 300td has this amazing MB-designed grease-leaking feature as well. Just one more reason the wheels look like crap.

dieseldiehard · #12 12-11-2007, 01:21 PM

Some mechanics tend to overpack the bearings, the factory manual states an amount something like 1.5 oz (in Grams) this can be estimated. Otherwise it expands and comes out and gets all messy like you see.

patbob · #13 12-11-2007, 03:19 PM

Quote:

Originally Posted by Jeremy5848

For the last month or so I've noticed that both front wheels of the '85 seem to be getting especially dirty in the area of the hub (see photo). It looks like grease from the wheel bearing is leaking out and brake dust is collecting on it and making it more obvious. I usually keep the car cleaner than it now appears but we've had just enough rain to make washing the car impractical.

When I repacked my front wheel bearings over the summer, I noticed the same thing. In my case through, it looked like the wrong grease had been used, causing the more volatile oils in it to creep out and literally drip off the hub. Looked like the previous mechanic had used the ordinary brown bearing grease instead of the green high-temp stuff MB sells.

To weight my grease, I just made a balance scale using a ruler & string, and used some coins as a counter weight.

Jeremy5848 · #14 12-12-2007, 08:06 PM

...when I popped off the center wheel emblem (both sides), the inside was clean and dry. No grease, no dirt. It is indeed just brake dust on the outside. Tomorrow morning the car gets a bath!

One of those since cable channels needs to do an investigation "How does it work?" on brake dust and how it can end up in strange places. I vote for the "vortex" idea.

Thanks for your insights.

Jeremy