Right rear wheel-bearing replacement

[quickster]

Anyone here ever replaced a rear wheel bearing on a 2002 sl2? If so, maybe a step by step procedure? Thanks for any help on this.

[KevinVarnes]

It has been a few years, but it is pretty simple. I believe the bolts have 10mm heads on them. I do not recall what the thread size is. There should be a hole in the hub (where the lug studs are) that allow you to get to each bolt with a socket and ratchet. remove all four bolts. The bearing is likely stuck in the knuckle. I bought some 100mm (don't quote me on that) long bolts the same size as the original bolts and screwed them in to the knuckle from the back side so the hex head is closer to the center of the car and the threads are pointed to the outside of the car. Screw those in so they push against the hub and it will push the bearing out. The brake backing plate may want to come off with the bearing so pay attention. If you do it right you shouldn't have to do anything with the brakes. Reassemble with the original hardware and you are done.

[quickster]

Thank you for the detailed information Kevin. I'm feeling better about this. I've got 294,700 miles on this car, and I'm shooting for at least 300,000. If anyone happens to know the thread size of these bolts, i'm interested, so i can get some longer ones if needed.

[KevinVarnes]

I have the bolts in my toolbox at home. If nobody responds today I'll post it tonight. I want to say they are M8, but I can confirm. They don't need to be anything special. I think I just picked some up at Menards. You are only using it to push the old bearing out and then you reuse the factory fasteners.

[quickster]

Thanks. This has drum brakes. Is it best to remove shoes/hardware? Also, 65 ft/lbs seems like a lot of torque on this size of bolt.

[fetchitfido]

Originally Posted by quickster

Also, 65 ft/lbs seems like a lot of torque on this size of bolt.

Correction: The 10mm hex head is tiny for the bolt size.
If the head was sized properly to the bolt it'd be 13-14mm.

You can usually hammer the bearing out from the inside once the bolts are removed but they could be too rust seized to the knuckle for that to work.
Removing the shoe & hardware shouldn't be required but if you choose the hammer route is probably a good idea.

[KevinVarnes]

Originally Posted by quickster

Thanks. This has drum brakes. Is it best to remove shoes/hardware? Also, 65 ft/lbs seems like a lot of torque on this size of bolt.

If you use the long bolt to press the bearing out you don't even touch the brakes. Everything stays in place on the backing plate. Unless you want to take them apart then have at it. Use plenty of anti-seize on the bearing boss that fits into the knuckle.

I didn't get a chance to check the bolt size last night. I'll check it tonight when I get home.

[quickster]

I'll have a slide hammer handy, but the plan is to push the bearing assembly out with the longer bolts, leaving the brakes alone. Thanks for the input.

[billr]

Be cautious using long screws to "jack" the hub/bearing out of the knuckle. The loads will be in a different direction than normal, and it is possible to bend the threaded ears on the knuckle if you have to force extremely hard with the screws. As always, a penetrant like PB Blaster or just ATF is recommended if the hub doesn't come out fairly easily. Note that WD-40 is pretty much useless for this purpose...

[KevinVarnes]

Well last night was a bust. I have several other bolts in my toolbox where I keep the screws that I did use so I cannot give you the exact dimensions of what I used. You will need to do a little digging and maybe some measuring, but I am pretty sure the bolts I used were 100mm long.

As I was driving home last night I also recalled how I actually pushed the bearings out. I did not screw the longer bolts in from the center of the car as I said up above. I'll try to give a good description.

Remove all four factory bolts. Line up the hole in the hub with one of the bearing retaining screw holes. Install one of the pressing screws through that hole and into the screw hole (same direction that the factory bolts came out). Screw it in far enough so the head of the bolt clears the inside face of the hub. Next rotate the hub so the access hole lines up with one of the other mounting screw holes. Do the same with another bolt. Now turn the hub so the access hole is not in line with either of the bolts that you just installed. Start unscrewing the bolts (you will need to use a wrench). Eventually the hex head of the bolt will come in contact with the inside surface of the hub. Evenly unscrew both bolts a few turns at a time. The bearing assembly should come out pretty easily.

I don't think you will need to apply nearly enough force with the bolts to break the knuckle. I mean use common sense, but you aren't going to be reefing on them with a 5' breaker bar. If you want to use four that would be even better, but it will take longer. I was fine just using two.

[quickster]

Your instructions are very clear, thank you. And yes, I will be careful not to bend the ears of the knuckle. Just got notified that the bearing assembly won't arrive until next thursday, so i have plenty of time to soak the old assembly with penetrant. If there's anything else, let me know.

[quickster]

Sorry i took so long to get back.
Just want to thank you all for helping my bearing assembly replacement go so smoothly. The longer bolts worked perfectly. The assembly came out easy. By the way, the bolts are M -10.

[KevinVarnes]

Nice work and thanks for posting the conclusion. Glad everything worked out for you.