Just how do you get them out @#$! Wheel Bearing Question 300SD
 

How do you get the old races out of the hub, any secrets short of dynamite?
I have a 300SD and need to replace front wheel bearings. I did one side but the other is a bear. THey are not budging
The bearing failure was sudden. Driving down the road heard this noise and then vibration. Jacked car up when I got home and wheel spin was not smooth. Almost like it was catching. Removed hub and noticed that the grease was very black and smelled funny. I think the last time I had rotors done the mechanics must have screwed something up. :mad: I mean 2 bearing failures (each side) within 150 miles of each other. :mad: Does not make sense. Only 156K on the car.
Anway back to my question , any advice on the race removal? I got some MB green grease and ready to pack new bearings (tips for this process) Do I have to replace the race?
Thanks in advance

yes
 

you will want to remove the race. you will need a large drift or a similar device. you lay the wheel an hub on the ground and drive the race out from the other side. flip the wheel and hub assembly over and do it again. no big problem. yes, he prob either left the bearings too tight or too loose.

good luck.

tom w

I find that not so much a large drift but a Long one is key.. Preferably a Very high quality drift w/ well defined edges. The lip you are trying to drive out is Small, so you'll need as solid a contact surface as you can find. I've also taken to heating the hub around the bearing race w/ mapp/propane gas and dribbling a bit of water on the race.. With that I can usually have the race out in 5-10 smacks at worst.

Who makes the bearings you are re-installing?

Jonathan

sounds like you know what you are doing-good description. Also, if I may add, use a surface behind the hub that's as solid as possible. I have a cast iron workbench. Less rebound concentrates the dissipation of shock force to the area between the hub and race.

Yes, it sounds like your mechanic screwed up.

If you still can't get the race out, despite all the good advice above, take it to a machine shop where they can properly press the race out, before frustration sets in and you run the risk of ruining the hub. Machine shop time isn't much for small jobs such as this.

Instead of a propane torch, you may want to heat the hub in the oven. I'm not sure if the hub is heat treated by design... some are, some aren't. If they're heat treated, you'll want to limit the temperature to 350°F. Shrink the race with ice cubes. Better yet, prefreeze a chunk just larger than the race, but smaller than the hub.

OK help me out here .... What is a drift :confused: and, I will give some of these ideas a whirl. :D
I got OE bearings, can't remember the name off the top of my head.
I also got the "green grease" tube from MB. Could the guy that did the rotors simply not repack properly or added non compatable grease.
(and for the record NOT my mechanic any more :mad: )
I noticed the green stuff in there but also lots of black looking stuff.
I know its after the fact, but trying to learn. Not that I will ever let anyone do my rotor work again. should always listen to Mama, if you want it done right, do it yourself. :rolleyes:
One other question
Do you "fill" the wheel hub cap :confused: with grease? and what is the purpose of the little copper flange thingy

Black and green suggests the mechanic took other shortcuts and didn't propely clean out the old grease. This is a no-no. This on top of not properly setting the axial play (clearance) in the bearing.

To properly grease the bearing, you have to pack the bearing and butter all internal surfaces with grease. Don't overdo it and don't completely fill the cavity.

Please search the forum using keywords "bearing axial play". I've had a lot to say on this subject. There's other things you need to know and you're sure to get useful pointers to do the job properly...certainly better than the previous mechanic.

A drift is simply a long rod (sometimes a scrap piece of metal) to transfer the hammer blows.

Also, I'm curious what type of bearings you bought. It should be stamped on the side with the manufacturer and country of origin.

The little spring thing in the bearing cap is a ground to cut down on radio noise. I would put some(not much) grease in each cap. The important thing is to pack the brg with grease in between each of the rollers and to put the specified amount of grease by weight in the center of the hub.I have welded a washer to the bearing race. This gives a large surface to hammer on to remove the race from the hub.I would take the hubs down to someone(machine shop) who has the proper tools to remove and replace the races. The rest you can do yourself. Take a good look at the spindle and check for damage. Grease with proper amount of grease, and set the endplay correctly. Re-check the endplay after a few days. You may find it has increased. Leading to funny handling and a spongy brake pedal.

Good luck. We have faith in you. Just farm out the race replacement and it will be all good bro. :)

The manual is very specific.
 

I don't have it on me but the manual specifies the exact amount of grease per side in grams. If there is too much it heats up and turns liquid, rinning out and leaving too little. Packing a bearing is done by pressing grease into one side of the bearing until it comes out of the other. Most do it by hand. I wear rubber gloves.

Also, check the diameter of the shaft. There is a spec for that too.
MHO Good luck.

if the race still won't come out, take it to a weldor and have him run a weld bead on the race and when it cools it will fall out

good to know I am not the only one that has had problems with these :D . Great ideas will let you all know how it works out

Bearing Race Removal
 

I had a pilot bearing race frozen inside the end of my Volvo's crankshaft. I used a dremel tool with a small grinder tip that cut through the race and it came out easily after that.

Factory bearings I just did in my C36 ended up being Timken.

got her done. Used Timken Bearings. Smooth as glass now. I am stressing as to the "correctness" of my final adjustments, and will keep close watch
Thanks everyone :)