Front wheel bearing replacement? both sides? - PeachParts Mercedes-Benz Forum

JamesStein · #1 09-25-2004, 01:32 PM

I need to replace the inner bearing on my left front. My question is are bearings like rotors? Should I go ahead and just do both the left and front inner and outter?

I'm leaning towards doing both the inner and outter on the left anyway, mostly because it was either done incorrectly the last time or the bearings were crap. The inner bearing isn't all that worn looking except for the broken ridge in it. Both the inner and outter were made by Timken and are stamped made in the USA so I doubt they are OE.

I can get just an inner bearing from Fastlane
~$18 made by NTN
~$15 made by FAG/FTE

Or I can get a set of both inner and outter, plus a new cap and seal for ~$36 made by SKF.

I don't know jack about bearing manufacturers. I also don't which of those manu's are the OE or OEM if any.

Any thoughts?

dmorrison · #2 09-25-2004, 01:44 PM

Replace both of them for piece of mind. The man who worked on the bad side MAY have worked on the other side. The bearing in the pictue shows damage by an object. His method of work ma have introduced an object into the bearing hub. Did he use the same technique on the other side?
If removing the hub do both bearings in that hub.
For the other side at least clean and check the bearing. Repack it and that way you'll know its OK.

Dave

samiam4 · #3 09-25-2004, 01:46 PM

That doesn't look like a normal brg failure...

My guess is somebody repacked the brgs and slipped when trying to pry the old grease seal out.
If bearings are properly adjusted, have clean grease-they can probably last the life of the car....

Mercedes actually sells a grease-same stuff as used on F-18's for about $8 a tube. Set the clearance up per the shop manual- 0.01 to 0.02 mm and your set.

For the other side, inspect the cap to see if it's ever been off. If not, you can probably re-pack them.

Michael

psfred · #4 09-25-2004, 02:04 PM

The rollers and race are shot, too, probably from dirt.

Replace bearing AND race (I believe Timkens come with both, but CHECK). Race will be TIGHT as Timkens fit that way. When re-installying, make SURE it rings when you drive it down, else it isn't seated correctly. Make sure the hub is clean, too.

you can get the Timkens at Autozone, they are about $18 a side if I remember correctly. They are prefectly good bearings.

Use synthetic wheel bearing grease, and don't over-grease the bearing itself -- too much is as bad as too little, as it will not circulate and any crud will STAY on the rollers.

Peter

rdanz · #5 09-25-2004, 03:49 PM

I trick that I have used in the past is to put the races in the fridge overnight
it helps when you install them.

nhodges · #6 09-25-2004, 09:38 PM

Use the Merceded Benz green stuff (grease). You cannot buy better! Synthetics included. IMHO!

Brian Carlton · #7 09-25-2004, 09:56 PM

How much grease goes into each bearing? I seem to remember 50g per side. The tube is 100g, so this seems to make sense.

Can someone confirm?

Kestas · #8 09-26-2004, 11:25 AM

SKF is the largest bearing manufacturer in Europe with 2/3 of the market. It has a good name there and elsewhere in the world. Timken is another excellent manufacturer. Definitely stay away from anything made in China. Trust me on this info - I have an inside track on this information. It looks like the SKF bearing set is your best deal.

The front wheel bearings on my car are Timken, made in France. I suspect they are original. So you may be right about these bearings being replacements.

As to the wheel on your car, it looks like some material broke off, and I would expect that material to have left marks and damaged the inboard races. That entire inboard set must be replaced.

The outboard set may not need replacement if the damage debris didn't mix and contaminate it. A trained eye can inspect the races and make the determination. Basically, the outboard race surfaces, including rollers, would need to be nothing less than perfect. If there is ANY damage, no matter how small, the entire outboard set must be replaced. If you're not sure about this, just go ahead and replace it.

I've seen many, many failed bearings, but I've never seen a failure such as the one presented in the photo. What happened? What is this 'ridge' you're talking about on the outboard set? It's also curious why you're in a situation where you need to install a third set of bearings for this car. Improper installation is often the cause of bearing failure, up there with seal failure. Failure is rarely caused by the bearing itself or the grease.

JamesStein · #9 09-26-2004, 01:03 PM

I'm not sure what caused it. Perhaps it was a shoddy repacking at some point I don't know. I got home from a long trip and there was a very loud and troubling grinding sound coming from the wheel when I slowed down. Perhaps the sliver of metal there broke off while at highway speeds and only got in the way when things slowed down. I jacked up the wheel to check for obvious outside damage and rubbing. I honestly thought I'd find the tie rod rubbing on the wheel or something of that nature. I didn't see any obvious external damage so I drove home 30 miles. Eventually the noise actually stopped. So I figured I had a stone or something behind the heat shield and that it had worked itself loose. The next day the grinding returned so I tore the wheel down. Rotor looked good but worn, no broken brake pads and no rubbing sheild on the disk. So I pulled the caliper off and the grinding was still there. The bearing was tight. No play that I could feel. So I pulled it.. I cleaned all the grease out of the hub and off of the spindle and never did find the metal piece that is obviously missing. There was plenty of grease in the hub so I doubt it worked its way to the outer bearing. I'm sure its actually trapped inside the inner bearing. The spindle looks fine. The inner race is shot so I'll certainly replace that, there is a groove worn into it where the metals was rubbing. I'll likely go ahead and replace the outer bearing and race as. During the rotor/hub removal I managed to make 5 distinctive dings in the surface of the rotor.. so that'll get replaced as well. The brake lines look a little old.. so I'll probably replace those as well. Fortunately the calipers and pistons look to be in great shape so I can leave them alone..

I hate spending money without need. But I'll likely just go ahead and replace both bearings on both sides since I am going to take the right side apart to replace the rotor.

Man these 'While its apart I might as well dos...' certainly add up.

Kestas · #10 09-26-2004, 03:01 PM

Quote:

Originally Posted by JamesStein

...Man these 'While its apart I might as well dos...' certainly add up.

Yes, but think of the labor from work overlap that you'll save.

You really don't need to replace the bearing on the other wheel. These aren't "service the entire axle" items or wear items. With proper maintenance, a wheel bearing can easily outlive the vehicle. In fact, I believe more bearing damage comes from DIYers attempting to maintain the bearings than from bearing neglect.

Kestas · #11 09-26-2004, 05:30 PM

Quote:

Originally Posted by Brian Carlton

How much grease goes into each bearing? I seem to remember 50g per side. The tube is 100g, so this seems to make sense.

Can someone confirm?

Each hub takes 50 to 70 grams of the MB grease, depending on the model. Of that amount, 15 grams is packed just inside the inner lip of the hub. Tube sold by MB - as described in the manual, PN 001 989 23 51/10 - contains 150 grams.

Psfred is correct about the amount. Not too much, and not too little. That's why MB - as opposed to other manufacturers - have a specification on the prescribed amount of grease. I read of too many mechanics stuffing as much grease as they can into the cavity. This wreaks havoc with the bearing's internal grease flow and thermal transfer characteristics. You also need to know which internal hub surfaces need to be buttered with grease after the bearings are packed to properly grease the unit.

psfred · #12 09-26-2004, 06:23 PM

I would guess the bearing was either defective from the factory (the cage was fractured or something) OR someone damaged it on installation or R&R, dropped it, etc.

I have seen one where the bearing was so bad the cage "rolled" through the rollers (salt damage in Ontario), but never one with just a chunk missing. Would grind terribly!

Keep them clean while repacking, should go very well. Don't overtighten, as they will fail in short order -- the ones I had to replace on the 280SE were so tight that the numbers were embossed on the thrust washer....

I know what you mean about "might as wells" -- new pads ended up being bearing, rotors, and caliper rebuilds on the 280.

Peter

omegabenz · #13 11-01-2007, 02:19 PM

How do most people here remove the old races (without the MB tool)? Pictures would be fantastic!!!

RF_126 · #14 11-01-2007, 03:41 PM

You can remove the old races with a good-quality punch, preferably a long one with a well-defined edge. Don't even think about using a screwdriver: it isn't tough enough for this job and there's a danger of scoring the inside of your hub. Assuming you have thoroughly cleaned all the old grease from the hub (and you do need to be surgically obsessive in this operation!), the inner edge of the bottom of the race is just visible when you look down inside the hub. Flip the hub over to see the edge of the other bearing race. This is a very small target: you need to be precise, and work your way around the race so as to minimize any tendency for the race to wedge itself stuck at an angle. They will come out gradually; take your time with them and then enjoy the beverage of your choice as a well-earned reward. Keep the old races as they make good drivers for the new ones.

omegabenz · #15 11-01-2007, 04:58 PM

In the past, I have used an air chisel on various w123, and w124s that I have. However, this car is a w202 C36 and my dad didnt really want me to use the air chisel...so I wanted to see what others have done.

I have good quality chisels/punches (snapon)