I always jack up the 123 with the hydraulic jack at the rear subframe bushing just inside of the jack hole. that is where I have also used my jack stands.

when I use jack stands at that location, I also use a hydraulic jack under the spare tire well with a thick piece of plywood as a back up. not to hold the car up, but just for a piece of mind. you never know when the next shaker (earth quake) will start to vibrate. I always get nervous with the rear wheels off and it jacked up.

the Differential should still be able to drop down jacked at the subframe bushing. To replace the diff mount, place the hyd jack under the diff with a little pressure. loosen the 2 22mm bolts and remove the 4 13mm bolts and lower. w/o a jack, the diff will drop about 5 inches, but still mounted to the subframe.

Charlie

OK, thanks. My intent is to jack up by the diff, put stands under the subframe bushing, and then go about my business.

So long as the diff will drop such to allow me to replace the rubber bushing, reseal the cover, and replace axles (if need be), then Im happy!

Thanks

At the start of this thread, Dave has it laid out really well.
should be a piece of cake ;).

Charlie

That is how I do it. I also have to remove the sway bar mounts in order to get to the two 22 mm bolts holding the diff to the diff mount. With a shallower socket (I use a deep 22 mm socket) this is probably unnecessary though.

Well I guess I just don't get it then... I read his instructions, but when I've read elsewhere about the diff mount, and they seem to say to lift the and support the car by the body, not the subframe, so the diff can move up and down a bit.
These instructions seemto indicate that supporting by the subframe may still allow the diff to move, to do the mount.

I just replaced both axles on my '82 240D.
The front of the differential is bolted solidly to the subframe, so I had to support the body to allow the differential/sunframe unit to pivot at the rubber subframe mounts in order to lower the differential for access to the upper cover bolts, and to jack it up higher than normal, providing the axles just enough room to clear the outer hubs during removal and installation.
I didn't try loosening the shocks.
Had I placed the jackstands under the subframe, it would probably have prevented my abilty to raise or lower the diffrential as needed. I decided to place the jackstands under the curved inner fender lip inboard of the rocker-panel, which did deform the lips somewhat. But that absolutely insured there would be no slipping.
Maybe next time I could add some blocks of wood, or some thick metal plates to distribute the weigh better, or find some jackstands with larger saddles.
Alternately, I could have placed my stands under the outer subframe mounting bolts, and still allow some subframe movement, but I wasn't certain those bolts would provide a secure perch on my jackstands.

Happy Motoring, Mark

This DIY says
"Install the axle shaft to wheel hub bolts.
(30NM torque 8mm bolt, 95 Nm 12mm bolt)"
I don't get which bolt is 8mm or 12mm. The bolt I took out of the hub is 13mm.
I'm assuming you are referring to the width of the shaft of the bolt, not the head, but I'm confused about witch one I'm dealing with and how hard to torque it.

It's refering to the shaft of the bolt. Typically, an 8mm bolt will require a 13mm wrench (Except for most Asian products, where an 8mm bolt takes a 12mm wrench!)

Happy Motoring, Mark

shims
 

I too used the GSP axles from AA. I bought two axles through AA online and had them shipped to my house. They were running a special on free shipping, plus I had a coupon if I purchased over $100. I think I paid $120 to two axles shipped to my door. I put them on this past summer and have had no issues. As mentioned in an earlier post the axles have a radius edge (instead of flat) so the shim/spacer won't fit flat against the axle. Actually, one of my axles had a radius edge and one was machined flat so maybe GSP made some changes and I just happened to get an old and a new one. There doesn't seem to be a problem with the one with the radius edge.

One thing that I think would be handy to have on hand is an assortment of the shims so that you can finish the job without having to run to the MB dealership (I assume that's where you can buy the shims). It's pretty difficult to measure this gap and then go out and buy the right shim. I had to "file" my original ones down a bit to get them to fit. I would rather have had an assortment of 0.5 mm width shims on hand to test fit. The filing took me a while as I was trying to be real careful.

What do I do with my old, original axles? I hate to scrap them since they can probably be rebuilt (I only replaced them as they had just started leaking oil from one of the boots). I'm not rebuilding them mind you but I hate to scrap "good" original MB parts. Would a company like CVJ want them?

if your boots only have slight cracks through the boots, and you replaced them quickly, new flexx boots can be put on, and the originals can be saved for when those Chinese juhnkers fail. I'll be renting my flexx gun soon. and the boots only run around 60.00 for both sides of the car. you should also get some M1 gear oil to fill the cans with.

I'm surprised to read that you are putting oil in flexx boots. I kind of reached the conclusion that they were too thin and that grease was the way to go with these "quick fix" boots.

By quick fix I mean it is way quicker to use a flexx gun and the thinner boots compared with cutting cans etc etc etc

I'm not picking fault - I'm just curious

Answer
 

I have used oil or grease for years, depending upon what the customer wants.

ditto.

I use exactly what my customers want. MB used the oil. I use the oil in my personal boots. some have asked for oil, some have asked for moly grease.
the flexx boots hold either without difficulty. I would not mix the two unless requested to by the customer, but I'd recommend against it.

Thanks for the response for the flexx boots that I bought I thought - no way am I risking oil in them! I managed to split two of these boots with the flexx gun.

I also saw a benefit to putting in grease. You can wait until the axles are fitted to the car before you tighten the clamps on the axle shafts. The grease won't fall out and by tightening at the end of the axle installation you can adjust the boot so that it has enough play and make sure it isn't collapsed.

This was a fantastic instructional. I would never have attempted it were it not for the level of detail included.

However, I would switch the order slightly. Trying to break the 22 mm bushing bolts is really hard when you're wrestling with the sway bar. I wasn't adept enough to pull that off with the breaker bar I had (it was too long from socket to pivot).

So instead, I dropped the exhaust pipe to give the differential even more room to drop. Then removed the 13MM bushing-to-floor bolts first (with the jack under it). After that, I lowered the differential's jack well beyond my wagon's fuel tank. Only then did I attempt to tackle the 22 mm bushing bolts with the necessary clearance.