The right local autozoo will have remans for $69.99. China and all that but come with lifetime warranty. Apparently the underwriters never heard of W123 :)

I've done a lot of checking, seems no one makes axles for '81 - '85 SD's.
Hope someone chimes in on weather this method is compatible for SD's.
Everything looks to be the same.

You should check again, they are avail new and used. 81-85 SD axle is the same as 123 I believe.

the 126 and 123 have different axle part#. there is no 84 300SD axle listed, but there
is one listed for the 84 380SE. same body. the sec uses the same axle also.

The 123 and 126 look to be the same length, but I have read they won`t interchange. have to try it one day.


charlie

Notes on replacing the rear axles in my 1983 300CD-T
 

I just replaced the rear axles on my ’83 300CD-T and this DIY and others were extremely helpful to me. Thanks to all of the posters.

I would like to add:
1. I used a black 3” ABS piping cap (acquired from Home Depot – plumbing section) plus a rubber mallet to place the new seals into the differential. You should gently and repeatedly tap around the seal with the cap so as to try and uniformly get the seal fully seated. If the seal starts going in crooked, solve the problem immediately. If you try to pull it out with your fingers/hand, you will likely inadvertently end up pulling off the little spring that fits on the inside of the seal and reattaching that spring will *REQUIRE* that you get the seal completely out.

2. The seal puller tool from Harbor Freight (attached picture) broke off as soon as I started placing tension on it. A worthless tool for this job. At Harbor Freight, they have various other tools that look a bit crow bar-like that can be used. I (carefully!!!) used a crow bar (the shorter curved end) to get behind the seal to remove each one. There are metal differential pieces close to the seal that you must be careful to leave unharmed. I only used the crow bar because I had no other tool to use. I believe that Sears also has inexpensive and good quality seal pullers that would work.

3. I found it a bit difficult to get the old axles off. One should just carefully try to move each axle’s joint that is closest to the wheel hub to try and give enough clearance that the axles can be worked loose from the wheel hub. I think that Dave Morrison’s idea to use a brass drift from the outside of the hub to gently pound each axle end toward the differential is a great idea. I used an old broom stick because I had no drift. Sears also sells drifts (haven’t used them though). Be careful to leave the splines in the hub undamaged.

4. I installed remanufactured axles acquired from CVJ Axles in Denver and so far, so good.

5. Despite using anti-seize on the threads of the two differential plugs (quite a few years ago though), I still had to use a torch in order to be able to remove them.

6. I used a Harbor Freight bottle jack for lifting the differential. This tool was absolutely critical for doing this job. Otherwise, I had the car on jack stands the whole time, front and back.

7. I did remove the rear brake calipers (setting them to sit above the brake disc and on the sway bar) and I can see why doing so makes the job so much easier. I recommend doing this, especially since doing so is such a minor undertaking.

8. I let the RTV (I used Wurth stuff) on the differential cover cure for 24+ hrs. after installation.


9. In order to pull the axle ends into the hubs completely, I used a long 8mm bolt (Ace Hardware item) plus two large washers (the same size as the ones I refer to in item 10. here) and a few smaller nuts in between that just slid (not threaded) onto the shaft of the bolt in order to pull (by turning the bolt) the axle end into the hub.

10. The washer/clamping disc/cupped washer/tensioning washer – it has a lot of names! This is the part that fits inside each wheel hub and through which the 8mm bolt fits on its way to screwing into each rear axle. The part number is 115 357 06 75. The factory manual calls for replacing both of these when the rear axles are replaced.

Differential side cover seal
 

Thanks for the helpful info from everyone.
I have a 79 300TD wagon
I have my axles off, and was just going to replace the side seals provided for the job (Elring S1346H05) when I saw that the seals in my diff were ones with metal outer edges, and a thinnish soft black rubber inner sealing bit.

Quite unlike the ones in the Haynes pic.

Are these the seals you are all talking about?

I imagine they will take some force to pry out.

Now the question: have any of you found them for sale?

See the first photo in post 18 of this thread. Yes, it took a lot of force to get the seals out. I don't know if your '79 uses the same seals as my '85; I was able to get the seals at a local foreign auto parts store. Click on "Buy Parts" at the top of the page and ask them if they have or can get the seals.

Spline Lubricant/ CV Joint cleaning
 

Jeremy,

Thanks for creating this thread, it has been an immense help as I try and attempt to replace all of my rear axle boots.

I have two questions:

1. What lubricant did you use for the splines when you reinserted them back into the differential and wheel hubs? It looks like Mercedes used some sort of red, thick grease. Is there a specific type of hub grease or will any high temperature lubricant do?

2. How should I go about cleaning the CV joints themselves? I've got both boots off and am ready to fit the new ones but I want these joints fully cleaned before I refill them with gear oil.

Also, the part number you gave for the seal was exactly the one I needed.

Thanks again,

Mike

Did you catch some trout?

Splines
 

I don't recall whether I used anything at all. I do remember that the left axle spine was so tight that I had to make a home-made puller to draw it into the wheel hub. If I put anything at all on the splines, it would have been whatever grease I had laying around, or maybe just some 20W oil.

I won't make any recommendations for cleaning as I've never done it myself.

Glad my thread has helped you.

Jeremy

The Can, with CV Joint End/slpine, seperated from the halfshaft.
 

I guess I won't be needing the Flexx gun anymore!

Jeremy thanks for the quick response, although I have much more important and pertinent question.

After removing the left rear axle from my 81 240d I was able to pull, with relative ease, the can with the CV joint contained within it away from the half shaft.

That is not suppose to happen correct? Aren't these pressed in with a hydraulic arm?

If they are, I fail to see how that would keep them together considering the inner and outer splines that connect the half shaft to the CV joint are not tapered (on my axle) nor does there appear to any evidence of crimping.

The balls, joint, and inner/outer splines appear to be in good shape with little to no visible wear and with only 100,000 on the car (I'm assuming these are the original axles since everything else is) plus no rear end damage, I find this incredibly strange.

I'll post some pictures tomorrow to give everyone a better idea of whats going on, I just need to let the batteries in my camera recharge.

Any help is much appreciated,

Mike

"The FSM says "Attention! Self-locking hex bolts with plastic coating (micro-encapsulated) may be used only once."

All this means is they put threadlock on the threads? I can do that! "

nope, it means they are stretch bolts, like the ones used on the flywheel and cylinder head. they streeetch after being torqued down. does not have to do with threadlock

i've reused caliper bolts pretty much every time I've ever taken a caliper off or even when I installed used 20+ year old calipers with no problems. wouldn't do that on the cylinder head, flywheel, or axles though

I know this post is a month back.

You have the older style differentil that was used until Jan/Feb 81 then the newer style was used with the seals that can just be pried out with a large pry bar.

The early style looks a little more complicated to R&R. there is the bearing Cap, Radial Sealing Ring, Compensating Washer and sealing Ring.

FSM states. 6. Remove lateral bearing cap. (that would be the 8 bolts that hold it on)
Pull off sealing rings. remove compensating washers for adjusting backlash or spread dimension (widening) and mark together with bearing caps (for left hand and right hand)

Then goes through rebuilding the Diff.

61. Place the previously removed compensating washers on bearing cap and insert new sealing rings into grooves of bearing cap.

62. On 1st version only. Mount both bearing caps with the designation "unten" (bottom) at the bottom. for the other versions, the position of the bearing cap is not important.

63. Slip both bearing caps with the initially mounted compensating washers into rear axle housing.

Note: if the bearing caps bind in bore of rear axle housing, settle caps by applying light hammer blows (Rubber hammer).
(at the 12, 3, 6 & 9 o`clock positions)

64. shows a special MB tool to use a dial indicator gauge.
this tool might have to be used when setting the preload on the bearings, after a total tear down and rebuild of the Diff.
Probably just replacing the seals is just a R&R of them. a few more steps than with the 2nd version.

Charlie

I disagree
 

I respectfully disagree -- the caliper bolts are not torqued enough to stretch. The only reason for replacement is the threadlock. There are similar applications such as the bolts that hold the W123 differential support bracket to the chassis. You could not possibly torque those bolts enough to stretch them -- you'd tear the captive nuts out of the chassis. It is puzzling why Mercedes does not just say "clean threads and renew threadlock."

Jeremy

Can, with CV Joint End/slpine, seperated from the halfshaft.
 

Alright, here is what happened:

As you can see, the inner half shaft spline slid out from the outer CV joint. It was relatively easy to pull out, only requiring a bit of force on my part to separate the two ends from each other.

Just to clarify, that is not suppose to happen correct? If that's the case, where should I go from here?

Thanks,

Mike.