cluch adjustment

A friend of mine has a mog and was wondering if the cluch can be adjusted at all or if it needs to be replaced . what it is doing is grinding going in gear at a stop but going down road seems fine but going in and out of reverse it grinds . any thoughts would be a help I didnt know if it could be adjusted like big trucks or not .thanks

Sounds like an adjustment should take care of it. I had a 404 that I had to replace the clutch in because it was out of adjustment and the throw out bearing fork pushed in too far and came in contact with the spinning pressure plate fingers destroying the pressure plate. If I remember correctly the adjustment is fairly easy and can be done from underneath. I want to say the measured amount of free play in the pedal is around 19mm meaning the pedal should start to feel hard after traveling 19mm down into the floor. There are a couple of great mercedes forums that will have this information. This is all from memory and I no longer have the manuals or the mog but have wonderful memories of changing the clutch which is a PITA.

Besides the clutch and adjustments, if it is a 406/416 check the hydraulic slave cylinder and hose. The hose can swell and not allow the pressure build up in the cylinder. Also check the slave cylinder and make sure it operates correctly. I have not turned wrenches on the 404 so others might chime in. Also (besides this awesome site), there is a wealth of knowledge on the benzworld.org unimog forum that caters to us mog-heads. Good luck!