Is it the FUNCTION indicator (the one in the speedo) or the one lower that just says "4MATIC" (which is the malfunction indicator)?
These components are very sensitive for compatability, they could have a bad match between the tx case and the sun gear, there were several changes.
No idea what the clicks are about. Here is some diagnosis info I have, in case it is the malfunction indicator and not the "function" indicator:
http://mercedes.justanswer.com/uploads/rmillerphd/2008-05-04_012344_A1.pdf
The function indicator in the speedo just means the system has detected slippage and is operating, is not a indication of a fault. The lower one, that says "4MATIC" on it means there should be a fault code set.
Typically the first thing you want to check with these old 124 4MATIC cars is what the going price of scrap metal is..........
Where'd the guy get the parts to fix it, any idea??
Gilly