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...

scottmcphee · #2 01-03-2014, 05:56 PM

... or live with the groaning sounds of worn rear bearings... forever. Jeez, that's a scarey and detailed story above. Why don't the FSM word it like it is bro'? You could re-write that thing, properly!

engatwork · #3 01-03-2014, 05:58 PM

Looking forward to the pics. thanks

vstech · #4 01-03-2014, 06:41 PM

Quote:

Originally Posted by scottmcphee

... or live with the groaning sounds of worn rear bearings... forever. Jeez, that's a scarey and detailed story above. Why don't the FSM word it like it is bro'? You could re-write that thing, properly!

it's actually VERY EASY to change the bearing compared to the 123's rear hub bearings!
however, you will need some special tools to accomplish it.
I read the DIY about using the slide hammer to remove the hub... NO EFFING WAY... I had one bolted to the hub and had a decent sized helper pounding on that hub for two days... it did not move. I even used bolts threaded through the lug holes, pressing against the bearing separator... to break loose the initial bind of the 20 some odd year old bearing... still nothing on them... don't bother.
just remove the entire spindle from the car. and take it to a shop and have them press out/in the bearing for you. much simpler. but be SURE they understand what will be needed. the new bearings come with a new snap ring, and a new axle nut. USE THEM!

Stretch · #5 01-04-2014, 04:33 AM

I'm about to do mine on my W201 this week - should be interesting...

winmutt · #6 01-04-2014, 08:28 AM

Did you try heat? What section of the FSM covers the bearings? I dont see it at all.

vstech · #7 01-04-2014, 08:35 AM

I"m not sure what I'd heat... the center of the bearing would need to be heated, without heating the hub itself... I guess I could heat the hub, cherry red hot, then let it soak the heat into the bearing, then rapidly cool the hub... that might work.
however, the press worked flawlessly, and it was very easy once the spindle was in there... and I have no idea how to replace the hub without the press, so far simpler to just take it all off and use the press.

winmutt · #8 01-04-2014, 08:39 AM

35-130 ? That looks like crap. My buddy just did his 335i, said it took about 20min as the bearing pops right in and out. WHY DOES IT HAVE TO BE SO HARD MB? The W123 rear was a royal PITA.

compress ignite · #9 01-04-2014, 10:01 AM

Stretch,

B90 Sir Tools - W201 190E Hub Removal - YouTube

I "See" this on offer when I "Froogle" it:

Sir Tools B90-M B90-M Rear Wheel Bearing Kit for Mercedes

BUT! Y'all have got:

Rear Wheel Bearing Kit for Mercedes Sir Tools B 90 -M | eBay

Gratis verzending

Stretch · #10 01-04-2014, 10:58 AM

Quote:

Originally Posted by compress ignite

Stretch,

B90 Sir Tools - W201 190E Hub Removal - YouTube

I "See" this on offer when I "Froogle" it:

Sir Tools B90-M B90-M Rear Wheel Bearing Kit for Mercedes

BUT! Y'all have got:

Rear Wheel Bearing Kit for Mercedes Sir Tools B 90 -M | eBay

Gratis verzending

Thanks

atomix8 · #11 01-04-2014, 04:01 PM

appreciated the detailed post!

Finally realize why the previous owner was charged over $800 for this repair. I thought they were just gouged!

vstech · #12 01-04-2014, 09:29 PM

got the replaced spindle installed on the car, assembled the links ,and torqued everything back in position... mounted the brakes and exhaust...

got the tires on, and took it for a test drive...

axle snapped accelerating up the first hill...

taking it all back apart tomorrow to swap out the axles...
fun.
car's been in my drive way since 10th of August... when it was brought in to change the flex discs...
when it was 90F outside...
it's now 19F outside... tomorrow it's supposed to be colder. and raining...

vstech · #13 01-04-2014, 09:34 PM

oh...
jay has decided that the 93 300D diff and driveshaft should be swapped out for the 87TD's diff and driveshaft... so I'm going to be pulling the diff out of my TD's parts car, and installing the driveshaft and axles from it into Jay's TD.

yea!
did I mention it's raining tomorrow in 19F temps?

jay_bob · #14 01-04-2014, 10:50 PM

I did some research on EPC for driveline parts between your 93 donor and the 87 wagon.

Differentials do have different part numbers
124.350.26.74 for the 93 sedan
124.350.19.74 for the 87 wagon
I suspect this is due to the input flange change. I looked at the internal components (ring gear, spider, etc) and they are the same part numbers.

The axle shaft history is interesting.
87 wagon:
original: 124.350.30.10
1st supersede: 129.350.40.10
2nd supersede: 210.350.84.10

93 sedan:
original: 129.350.40.10
1st supersede: 210.350.84.10

So the axles shipped with the 93 sedan were approved, at least for some time, to be able to be used in the 87 wagon. And both vehicles eventually cross to the same 210 number.

Note that my W210 1998 E300D takes that exact same 210.350.84.10 axle and it has not been superseded. That tells me they developed a universal one size fits all axle, when they developed the 210, to take care of all applications in the 124 with the same length part.

Devil's advocate: I wonder if someone substituted the 129 axle into the list for the 87 wagon without thinking about the engineering ramifications. Wouldn't be the first time something like that has happened, where the bean counters think they can be engineers.

On the other side of the argument, inside the axle shaft the only listed replaceable part is the inner CV joint. It is the same part number 140.350.08.13 for all 3 cars. And the cup that fits the diff output flange is the same 124.357.02.89 for all 3 cars as well.

So in conclusion, I'm starting to think the axle failed due to prior damage and not due to overload. However I still think we need to swap the diff and driveshaft, because I am concerned about the size of the diff input flange and flex disk being bigger in the wagon. They must have had a reason why it is bigger in the wagon than the sedan.

vstech · #15 01-05-2014, 01:40 AM

I agree.

but I suspect the reason is ride, not strength.

I can't wait to get the failed axle apart to see where it broke, and to see if it's dimensionally thinner or something... the way it felt when it snapped... just POP... no grinding or binding or anything unusual, just POP...