W116 Rear Wheel Bearing Wrench
 

I've been told that a special wrench is needed to R&R the rear wheel bearings on a '79 300SD.

Does anyone know where I can get one in NE PA or could someone loan one to me?

P E H

Tool:
 

I answered your question on the post where you were giving the guy trouble about typing the wrong size socket.
Charlie

Charlie,

I'll look for it.

P E H

Charlie,

I didn't realize I posted twice about the 24mm wrench.

Ok about the bearing wrench, but let me ask you a question or 2 about using it:

Do I remove the axle shaft from the wheel bearing spline and use the bearing tool in the hole the axle came out of?

What is this crush washer thing? There is a cup type washer in the bearing kit I got, is that it? It seems awful sturdy to crush.

Thanks for any info you can give me.

P E H

Tool:
 

I just got the tool Thursday. Haven't even opened it.
I have a rear brake job coming up. So I am still in the dark.
Hope someone else an help you.
Good luck.
Charlie

Charlie,

Rear brake jobs: Been there, done that.

If you are just replacing the pads, all you need is a punch to knock out the pad pins. You can make one out of a nail by grinding the point off. You also might need some hand tools like pliers, screw driver, wrenches etc.

Even if you are removing the rotor, you don't need the bearing tool. First remove the old pads and spread the pistons all the way open so new pads will fit. Remove caliper and wire it to something to support it. Then knock off the rotor with a soft hammer. If it only comes part way off, its hanging up the parking brakes shoes. Turn the star wheel inside the rotor to release the parking brake shoes. Then remove the rotor. Check parking brake shoes for wear or lining coming off the metal shoe, replace if necessary.

Clean as required and assemble in reverse order. Some mechanics put brake grease on the back of the pads to prevent squeal but you might try the brakes first. I have never needed the grease.

NOTE: when you spread the pistons, only do one at a time so the hydraulic pressure doesn't push the piston of the caliper. When you spread the second side, put a new pad in place on the opposite side. If the pads are too tight to push in place, you might have to grind or file a little off the ends of the metal part of the pad. If there is a lip on the drum brake inside the rotor, grind it off with a hand held grinder. Re-adjust the parking brakes by turning the star washer. You do it thru one of the wheel bolt holes.

That's about it. Good luck

P E H

PEH,
Sorry for the late reply - I just got back from a work trip...
to answer some of your questions:

Do I remove the axle shaft from the wheel bearing spline and use the bearing tool in the hole the axle came out of?
Yes. you only need to remove the axle shaft from the hub and then tuck it out of the way. There is enough room to R&R the bearing, trust me.

What is this crush washer thing? There is a cup type washer in the bearing kit I got, is that it? It seems awful sturdy to crush.

This is in fact the crush washer. The threads are very fine on the hub nut, so you have a lot of mechanical advantage and micro-fine adjustement ability to correctly set the bearing just like you would on a front bearing, except you can not back the nut off if you get it too tight, you then have to replace the crush washer.

a link to this tool is here: http://www.zdmak.com/benz%20tool.htm

and here is a pic:

pic of tool:

Q - Rear Wheel Bearing Wrench ?
 

ok, call me a chicken and let's get it out of the way first and move on.

I've retained a good local mechanic (though not a MB mechanic) to perform the replacement of a rear wheel bearing on my 85 300TD (wagon). I bought the bearing kit from Phil and the weird bearing tool pictured in the post above this one. I've been looking for the proceedure and done bunches of searches here and not been able to find it.

Is the tool pictured above used for the removal of the bearing or to torque the retaining nut and crush the crush washer?

Any and all guidance is much appreciated. thanks, Frank

I won't call you chicken, brother. This isn't that much fun if you don't know what you're doing-as I didn't. The pin wrench socket fits the slotted nut inside the axle flange. You remove the axle first and then you can get to it. Does your mechanic have Alldata? Thats how I got mine, but all the specialized tools and warnings were scary. How about Braingears or Skinnerbox? I know that I needed guidance; it wasn't exactly intuitive (for someone used to Subarus and VWs). Someone here with more experience can help you better than me recounting my fumblings!

Don't give up!

Scot

PNO Tech.. Now I am scared.. should i , um, remove my confidence in my local mechanic? His boss changed from using Alldata to...um..mitchels?, or something like that. When is employing the 'batter part of valor' indicated?

There is nothing magical about a mechanic. He is going to find and follow directions from a manual. If he has never done it before, you may, or may not get the results that you pay for. If the manual is very specific and he is very careful, then there should be no problem.

But, I don't have a lot of confidence in most mechanics. Way too quick to have the answer to the problem...............many times an incorrect answer.

The procedure that you are asking for is very specific and damage to the bearings can easily be done if it is not performed in a proper manner with the correct tools.

Brian.. where do I find the proceedure?

The mechanic is old and wise and has not 'committed' to the opperation yet, waiting to assemble the info first. His young padawan was ready and eager but.. the young can be reckless and the master is teaching patience, so there is no harm done yet.

I searched in here but didn't find it.

Frank

Seafood,

You can get information from the MB manual to R&R the rear wheel bearings. Actually is not rocket science, and any competent mechanic should be able to do it. Most important is to set the end play .001 to .002 inch the first time so the crush washer is not crushed twice.

Yes the tool is used to turn the slotted nut, both on and off, and it is absolutely necessary to do the job. You will need a long breaker bar and maybe a pipe. You will also need something the keep the flange from turning. A pipe welded to an old brake drum will work.

The rear axle is sort of like the front axle in reverse. The slotted nut that holds the bearing assembly together is on the inside and the axle goes thru the center of the slotted nut

The manual shows a number of pullers are necessary to remove the old parts. I did it with just careful cutting with an acetylene torch and used a dremel tool to smooth the nicks. Hardest part is getting everything apart, that's what the acetylene is needed for. I had to cut the original slotted nut because it was so tight and cut the bearing races and cones to get them out because I didn't have the pullers. After that its just reassembling the new parts and adjusting the end play.

P E H

thank you, PEH. I will pass this and any other info along to the mechanic and his young padawan tomorrow or monday.

This, and both past and future advice is gratefully acknowledged and appreciated. Frank