Souring Rear Bearing Parts.. - PeachParts Mercedes-Benz Forum

luketmarx · #1 01-30-2019, 01:46 PM

I'm replacing/repacking bearings in my '76 240D. The left side needs new bearings, but the right is OK, I just need new seals and crush washer. But I haven't found just those parts for sale anywhere, I need to buy the whole kit for over $100. Any tips on where to find just the crush washer and seals?

Sugar Bear · #2 01-30-2019, 03:07 PM

Luketmarx, If you are re-packing the rear wheel bearings...I am impressed. Most wait until they fail; but, with grease over 40 years old they may fail soon.

If the crush washer you are referring to is a crush "collar or sleeve" on the hub and it is removable I'd bet it could be reused if you plan to use the old bearings. With the same bearings its size wouldn't be changed or crushed any additional to get back to the same preload.

Your plan to take it apart is definitely the better way; however, if you cannot find the parts to do so, GM had a tool to inject grease into the rear hubs on Corvettes (similar set-up) without hub disassembly. It was shaped like a crevice tool on a vacuum cleaner except the end was curved the same as the hub so it slid between the seal and the hub. There was a zerk fitting on the other end of the tool. Point of this is that you may be able to inject grease very carefully into the hub at the seal with a needle point grease injector.

Good luck!!!

luketmarx · #3 01-30-2019, 04:42 PM

Thanks! Well, fact is I did have bearing failure on one side, so I thought it prudent to check the other side too...

The directions I saw for how to properly install the bearings is to crush that collar to a certain spec of in-out play on the hub, and if you go too far you need to start over with a new collar. I'd love to re-use it but I was advised against...

And I saw it on the internet. So it must be true?

Sugar Bear · #4 01-31-2019, 09:21 AM

Yes the collar gets crushed which reduces the end play but; unfortunately, it is a one-way action, once the collar is crushed it cannot be "uncrushed" so if it is too tight you must start over with a new crush collar. The key is to tighten the assembly in very small increments/bumps. On a clean and re-pack, re-using bearings if you can, there shouldn't be a need to crush the collar just put everything back to exactly where it was.

Consider using correct thread locking compounds wherever possible and/or needed.

If you need new bearings the chances of being able to re-use the collar go down but you cannot tell until it is assembled.

Good luck!!!

gmog220d · #5 01-31-2019, 01:23 PM

Quote:

Originally Posted by luketmarx

The directions I saw for how to properly install the bearings is to crush that collar to a certain spec of in-out play on the hub, and if you go too far you need to start over with a new collar. I'd love to re-use it but I was advised against...

In case you don't have it the book says 0.04mm - 0.06mm is the end play spec for the rear axle shaft flange. Have you got a dial indicator scaled small enough to make seeing that measurement easy?

I think if I were in your shoes I'd use fresh crush sleeves so that I'd only have to go through the assembly process once, particularly for the side getting new bearings. For the side going back together with the original bearings, reusing the crush sleeve could work just fine, but you might run the risk of having to take it apart again to replace the sleeve with a new one. You'd have to remove the inner grease seal to do that and could damage it in the process. Small beans, but still, beans.

I read about an old school trick for getting around used crush sleeves that are crushed too much. Install a shim to space out the bearing races again, to give you another shot at getting it crushed right. Maybe best reserved for desperate times!

luketmarx · #6 02-07-2019, 10:51 PM

Quote:

Originally Posted by gmog220d

In case you don't have it the book says 0.04mm - 0.06mm is the end play spec for the rear axle shaft flange. Have you got a dial indicator scaled small enough to make seeing that measurement easy?

Thanks for that spec! No I didn't have it, and was hoping I could find it...thanks!! I have access to a dial indicator that will let me make the measurement. I went ahead and ordered new bearings for the other side anyway, though the outer bearing looks OK and is a giant pain to change so...going to keep that one there, just re-pack. I'll replace the other bearing and all seals and crush collar.

I buggered up the threads on the bad bearing side. Ended up having to take the hub to a machine shop to clean up the threads on a lathe, cost me $50. Then I ordered a new nut. Pelican Parts didn't sell just the nut, so per their expert's advice I just went to Mercedes...nut was $5.95. Shipping from Scottsdale AZ to Richland WA was $19.

So, I'll finish putting the bad hub back together (now a great hub!), and install my new boot kit for my CV axles while I wait for the nut to arrive for the other side.

Meanwhile I'm almost done disconnecting everything from the engine, next is driveline at trans and engine mount bolts, then out she goes. The "new" 617 is sitting right next to her, I'll pull that one next. I have until March 4 when my new job starts to do this swap..haha probably won't finish but hope to get seriously close at least.

Thanks for everyone's help on this post.