OK... W124 Rear bearings are a BEAR to replace - PeachParts Mercedes-Benz Forum

vstech · #1 01-01-2014, 06:09 PM

I've had to RE DO the install 3 times now... but I've got it DOWN now.
pictures will be added to this soon...

I'm sure if I'd followed the FSM and had all the FSM specified tools, it would have been smoother.

first off, you need to TOTALLY support the spindle when you press on or off the hub or bearings.

a HIGH QUALITY bearing separator that spreads at least 3" is critical to remove. DO NOT ATTEMPT to press off the bearings without one. the JUNK sold at Harbor Freight is junk, it will destroy your spindle, and the backing plate.

somehow, I ended up using the HF junk, and it of course gave out JUST as the pressure was highest and caused damage not only to the backing plate, but also to the caliper mount ears... I was able to hammer them back in, but I may end up replacing the spindle as well...

arrgh.
anyway, after the spindle is out of the car, and ready to press apart, you need to secure the QUALITY bearing separator to the hub. then set the spindle where the hub can pass through the press. you push out the HUB from the spindle bearing FIRST.
the press needs to be large enough for the hub to pass through 6" spacing will do it. the 4" presses will not work...
after the hub is out, you will see a GIANT snap ring. you will NOT be able to pry or tweak the ring out, you will need to get a HONKING HUGE locking snap ring tool.
most likely, you will have difficulty with the snap ring, as you just pressed the hub against it, which will most likely cause the bearing race to bind on the snap ring. the solution is of course to press back on the snap ring, and gain some slack by reseating the bearing race... fun.
ok, after the ring is out, you need to press out the bearing, then clean out the spindle and prepare it for the new bearing. keep the old bearing, as it's PERFECT for installing the new one.

you need to set the spindle on the press, and it needs to be flat. I had several old bearings sitting around, so I used one of them to sit on the plate, and another to press the new one into place.
then I install the NEW snap ring.

next step is to install the backing plate if you removed it, as it's GOT TO BE IN PLACE before you put on the hub.

next the spindle needs to rest ON THE INNER RACE of the bearing. set the hub in place, and press the hub all the way flush to the inner race.

done.

ok, the hub should smoothly turn. it'll not spin like the front will, as there is a lot of tension on everything, but there should not be any gritty feel or play to the hub bearing.

reinstalling the spindle must be done in a SPECIFIC MANOR...

the links need to be attached to the spindle, and the axle must be parallel to the vehicle before any of the bolts are torqued (70NM...)
if the links have not been loosened on the subframe side, you can attach the spindle loosely to them, then I installed some lugs to the hub, and used a floor jack to hold the spindle up into position for torquing the links with the axle in the horizontal position. the trailing bushing should NOT be connected to the LCA for this section... after all the links are torqued, then raise against spring pressure as much as you can, and align the trailing bushing in the LCA and install the bolt. I had Jay stand on the lugs to hold the spindle in position while I lined up the trailing bushing for the bolt. torque the bolt (120NM ) the Trailing Bushing is not specific to torque in position. THE FSM SAYS YOU DO NEED TO SET IT WITH THE AXLE HORIZONTAL, but I do not see why... it's a ball joint style bearing... nothing is fixed, like the bushings in the links are...