Front wheel bearing seal W124
 

I would like to check & repack (NOT replace - unless damaged) the front wheel bearings on my W124. What shop technique is used to remove the rear seal from the hub to get access to the inner wheel bearing?

Thanks,

You will pretty much destroy the inner seal when you remove it or at least I always do. I just use a screwdriver to pry/work it out. The seals are pretty cheap even from the dealer. There is a number on the side of it that can be used for a cross reference to obtain another one from a bearing supply house if you can get it out without messing up the section with the number on it.

I checked the shop manual and it says on W201 cars to pry it out with a screwdriver and W124 & W129 models to use a drift to remove the bearing and seal together. Presumably the screwdriver does not work well on newer cars. Anyone have luck finding a drift to nondestructively move the inner bearing + seal?

Thanks,

Seal Puller - part #56750. Pep Boys carries a line of the tools presented below:

http://www.lislecorp.com/tools/catalog/bearings/index.htm

Thank you for the link!

Even using a drift will likely damage the seal when the bearing jams against it. Just plan to replace it. Since it is rubber, it will deteriorate eventually anyway.

Steve

I plan to replace the seal - just don't want to destroy the bearing.

Thanks,

Although a new seal is always recommended by the seal MFGs and as a shop disclaimer, the seal comes out unharmed when you knock the bearing out and could be used again if a new one is unavailsable. Wheel bearings are amazing animals. We look at the big wide low profile tires with confidence, but how many people relalize that their whole 2 ton car is being supported on six tiny surfaces no larger than about 1/3 of their pinky finger nail. Then these same little guys are expected to spin at extremely high speeds for 100,000 miles. Think about it.

Peter

You will be able to get the seal out without damaging the bearing with a little persistence and creativity, even without special tools.

Worst case, you can (carefully) chisel all the way through the seal's outer metal ring to release the pressure, or drive it towards the center until it "relents". Just be careful. You can use a brass punch or chisel if you want to be very safe, though this operation may distort the brass somewhat...

Best of luck.

I've tried using a punch and vice grips once. It was not a lot of fun, but it worked. I'm hoping for a cleaner method. :) One person I've talked to outside this list suggested the end of a hammer handle to drive both the bearing and seal out at the same time.

Thanks,

Guess mine were just not that tough.

Wooden/plastic handle (or whatever similar implement) should cause no damage pressing on the bearing. Sometime PVC pipe will work too, depending upon the diameter. Just keep it clean.
I have used that method successfully on other cars.
I have a cheap seal/bushing install set with various soft aluminum heads that works for this too. I see these around for cheap. Honestly, this is not the 'ideal' method.

In terms of prying, it can help to place something across the center of the hole to use as a fulcrum for the prybar. The other side of the hole does not make a great fulcrum for a straight prybar. That is why the special seal puller (with the perpendicular handle) works. This technique can work with vise-grips too sometimes.

I am having trouble visualizing this particular seal. Is the space between the bearing and the seal particularly tight? Guess I've done too many of these...

Much as I tried I couldn't remove the seals on my car without damaging them. I couldn't get a good grip on the seal body lip inside the bearing to pry up on. Plus the seal walls are steep and give lots of resistance to romoval.

Kestas,

What procedure did you use to remove the seals? I'm already planning on replacing the seals, but I don't want metal frags in the grease as a result of sloopy shop procedure... ;)

Thanks,

Wooden hammer handle works for me.


Peter

Any time the bearing is removed (opened), the grease needs to be replaced, especially if the seals are removed. This is because it's hard to breach the grease charge without contaminating the grease. It is imperative to NOT allow the grease to get contaminated. This includes metal burrs, brake dust, anything. When you wash out the old grease, any contaminants will get washed out also.

There is no such thing as a quick visual inspection of the wheel bearings. You either leave it alone or properly repack the bearing.

I think I used a crowbar to remove my seals. When I reinstalled the seal I put a flat piece of plate steel over the seal and hammered it down. Using a press is the superior method.

Don't forget to properly set the axial preload on the bearing. This has a significant effect on bearing life.

Kestas,

Why can't I remove the outer wheel bearing and reinstall it without repacking it? How have I breached the grease doing that with clean fingers? If I set the bearing down, I set it on a clean sheet of wax paper.

Thanks,

The grease should be nothing less than perfect. It is difficult to open the greased area without having debris fall onto it. If you can guarantee that no debris would rain on the grease then no repacking is necessary. But no mechanic would advise that. Considering all the road grime and brake dust on the outer surfaces and crevices, repacking a bearing is the recommended practice after opening a bearing.

Thanks for the clarification.

Brian,

Professionally I don't have a problem pulling a bearing to perform some other service and throwing it back in as long as I was careful with the environment as you say with the wax paper. I pull the outer bearings to change rotors and ball joints. I lay the parts aside in a clean rag and throw them back in to finish the job. Back to your original question. If there are no grooves or spall marks on the old bearing and they weren't growling, by all means clean and repack them. Slight discoloration on the bearings is normal. I just wipe most of the old grease off with clean rags and repack with my hands. the new grease forces the old grease out. Considering how many bearings I've packed, it adds up to several million miles and I haven't had a problem using this method. As someone else pointed out, bearing pre load is what is critical. Be sure to get that right.

Good luck,
Peter