Does the trans need to be dropped to replace the rear transmission seal, or does it only need the driveshaft removed? Where do I find a manual transmission output seal for this car -- none of the Internet parts sites seem to have any manual trans parts?

Between the brake issues, the rust hole (since repaired), the new alternator and this, this car has been a hopping c**taroo in the last month or two.

You can look up the part here:
http://www.everythingbenz.com/z/epc-mercedes-parts-info-diagrams

I am not sure on the Manual Transmissions but I think on mine the Nut that Holds they Yoke to the Transmission needs a Special Socket.

I am not sure if the one in the Pic is the correct one or not as it only has output shaft and does not say output shaft on What? Hower, the Pin type socket is what I am speaking of.
Once the Yoke is off I think you have room to get some sort of Seal Removing Tool in to pry out the Seal.
Do a Google Image Search to see some pics of Seal Removing Tools.

Take a good look at the area on the Yoke that the Seal Lip contacts. If there is a really deep groove there a new Seal may not last long.

I don't know if they make them for your application but for that problem they make somthing genericaly called a Speedy Sleeve. If they make one for your Yoke the Sleeve gets pressed over the Yoke and provides a new ungrooved surface for the Seal to ride on.
Some come only as a Seal and Sleeve set and other claim you can use the Stock Seal. More than one Company makes a similar items.

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84 300D, 82 Volvo 244Gl Diesel

Access to the rear seal is possible with the gearbox fitted in the car.

You'd have to remove the propshaft and find a way of holding the yoke in a fixed position to remove the nut on the output shaft. This isn't a job I'd want to try and do under a car on axles stands - a bit nicer to do on a four post lift I imagine.

I suspect that you will not have the more modern 12 point nut



(http://www.peachparts.com/shopforum/diesel-discussion/341253-717-412-5-speed-manual-gearbox-refresh.html)

Probably going to be a slotted nut like this one (on an automatic transmission)



(http://www.peachparts.com/shopforum/diesel-discussion/304903-722-118-automatic-transmission-rebuild-monster-diy.html)

In either case the nut is peened to the output shaft - even off the car working on a bench these nuts can be testing.

I've never bought the slotted socket for the slotted nuts - it is unfortunately a different size for manual gearboxes, automatic transmissions and rear wheel bearings / rear wheel hubs. The replacement nut will be 12 point anyway - you can't get new slotted nuts from the dealer any more - so buying the slotted socket tool is pointless in my opinion. I use hammer punch and a little grinder to remove the peened metal and the nut.

As for spares - the dealer is probably best for just the seal.

If you post up your gearbox type 716.XXX I might be able to show you the way to an Elring or Meyle (yuk) or Febi (yuk) full reseal kit that might be cheaper than the dealer seal!

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1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!