PeachParts Mercedes-Benz Forum - View Single Post - Replacing the rear wheel bearings on a W123, W126

dmorrison · #7 12-01-2007, 11:00 PM

Picture #26
Here the socket is installed and the ratchet attached. I found it necessary to use the dead blow hammer to seat the socket all the way in. I tightened them as much as I could without the black pipe pry bar.

Notes on tightening the assembly.

Hammer the socket into the nut after each tightening of the assembly. THIS IS VERY IMPORTANT or you can break the socket tabs, don’t ask how I know.
Now with the socket installed and the ratchet against the lower control arm. Use the black pipe and the 2 lug bolts to tighten the assembly about 1/8th of a turn.. Measure the tolerance of the hub with a dial set up on a base. Hammer in the socket again and then turn the assembly with the black pipe another 1/8th of a turn. Do this until you have tighten it to within limits.

The limits are 0.04-0.06 mm
SAE .0015-.0023Inch
Or 1 mark on my dial gauge is .001 Inch

If you over tighten the assembly. YOU MUST REMOVE THE CRUSH WASHER AND INSIDE SEAL AND START OVER AGAIN. You will have to buy a new crush washer and inner seal.

Picture #27

This shows the dial gauge tolerance I achieved. One is pushing on the hub and other is pulling on it. I have about a .0015 setting.

Picture #28

How to set up the dial gauge for your reading. I have the dial gauge and base I bought from Harbor Freight.

Dial
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=33675

Base

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=5645

Picture #29

After tightening the hub to tolerance. You “lock” the nut in position by punching the nut flange into the openings in the hub shaft.

Picture #30

Shows the nut flange punched.

Install the drive axle into the hub and tighten the nut to the specified torque for your type axle. ( M12- 95Nm, M8-30Nm )

Install the rotor on the hub.

Install the calipers over the rotor and bolt onto the wheel carrier using loctite.

Enjoy.

Dave