4matic Transfer case

I have a 91 4 matic, and the transfer case is leaking.
I've been told that the only cure is to remove and replace the unit.

Is this true?

Since I'm not in the US, a MBZ sourced transfercase is at least $2500 for me locally. and my local mercedes enthusiast has told me that the NE US is a great source for rebuilt 4 matic transfer cases. which are about half this price.

Is this true?

Thanks for your advice in advance

Russ
(France)

[Michael]

Is it leaking transmission fluid into the differential? You can tell if you check the fluid level of the differential, and it's over-full; also, tyranny fluid would be correspondingly low. If so, then much more than likely you're correct in your diagnosis.

The auto box is fine, no fluid loss, just the fluid from the 4 wheel drive system.

The leak is relatively constant,(about a liter a month) unless I get it out on the highway, then it seems to be speed related. and then I leave a nasty smoke trail, as it's dripping on something hot.

do you know anything about rebuilt transfer boxes available in the states?

Thanks

Russ