In my travells i have come across the hydraulic schematics of this car and unfortunately i cannot post it yet , if any one has more info on this car , i am about to purchase the 124 cd rom , i am hoping it is very specific on this model , if it is not i will be in the hunt for true info on this car , i have found that these cars have many "model specific" parts, and of course that is added to the cost of parts ,

This test valve post is one that i hope we can resolve about damage to the suspension, transfer case.

i can apply test valve and light comes on and then i can turn off and light will come off , i have also changed all the fluid on this car except front diff , and trasnfer case indeed is a sealed gear box and a sealed hydraulic clutch,(viscous coupling), if any of the 2 fluid mix , Ie internal leak means rebuild on tc ($3000) . indicator is you check fluid at fill of transfer case and if fluid comes out (excess of 2to 3 tbs) is a true indication.

my tech here an ajax inform me that dextron 3 is fine on tc , zhm fluid for hydraulics and 80 90 hypoid is good for front/ rear diff. i have mentioned a few item on this post previously , i am still looking to answer if damage will be done to transfer case , hydraulic suspension aside the rwd mode is also i believe a locked hydraulic system , which i believe means what pressure is in the system stays in the system . as proof there is always fluid in the shock and as the they are in line with accumulators which are gas filled, that is where you get the "ride" and feel .
I am getting this information from a few mercedes mechanics in the area , of course that is through looking at the diagram and through working on this system , i am most likely incorrect is some of these statements, but i will never find out unless i make these statements , and someone knows better.

thanks for the info.

p.s. 3 of the gentlemen i talked to have thier own shops and one is the shop foreman at mb durham,