I did the seals on my SD last summer. I ordered them from Fastlane here. Check there and see what it shows.
BTW, not too bad a job, except pulling the axles out.

Differential seal
 

I need to replace one of the differential output seals (axle shaft seal in Hayes manual) on my 1983 300D, is the part # the same as the pinion seal? My local parts store only shows the pinion seal for this application. If its not the same does anyone know the MB part # or any other manufacturer part # that I can cross reference. Thanks in advance.

"except pulling the axles out."
This has the possibility of being a huge understatement... be sure to read the shop manual and posts about how to do this.... and don't lose the clip from the inside of the third member....
I think to do this properly and safely that one needs to be able to get the car high in the air and be able to adjust the height of the wheels also.... and there is the possibilty that the third member is supposed to be unbolted and independant control of its height also...
I did not have access to my concrete shop floor, my rolling jacks would not roll of course in dirt... and I did not get my wagon high enough to start with... it was the worst mechanical job in my 30 years of doing it myself...

follow-up
 

The differential is on my workbench right now, anyone have a part #

That will really make it easy.... just install the half shafts at the right distance as you take the differential up to be mounted....

How did I end up being the poster of this thread:confused: :confused:

" anyone have a part #"
Didja check Fastlane yet?

You are a natural LEADER ?

Always keep a spare old half sheet of plywood around for use when jacking in the dirt.

:D LOL :D
Yeh, right;) :p

no listing
 

There is no listing on FastLane, I have E-Mailed PartsShop but no response yet. As I stated before the pinion seal is listed by local parts shop but I dont know if part number is the same for the axle shaft seal.

Now that's wierd!:confused: Wonder why?

part name/number
 

Rickg do you recall the part name you used when you odered from fastlane? maybe I am just not calling it the right thing. PartsShop still hasn't responded.

I used the "side differential seal". Go to "transmission" parts, then scroll down to "diff. side cover seal". I looked that up for the 300D, and you're right, it came up not available. I checked another web site I have bookmarked for parts, and got the same results.:confused: :confused:
There must have been someone else on this forum that's needed these seals. Anybody out there?

If you can't find it on the web site, call Phil. He has multiple parts sources and is always happy to help. The phone number can be found on the Fastlane page.

Good idea. Phil's a very helpful person. Just may be busy and not able to answer emails right away.