My standard procedure for newly acquired old vehicles is to change the fluids, and after reading about corroded synchros, etc on here I decided to get going on that.
My Pantera Tech Info manual gave me false hope that I’d find a nice fill plug on top of the ZF unit but it seems that was long gone by 74 . . .
only real snag was getting at the fill plug / overfill alert hole on the side. If it was a bolt head that would have been easy, but it seems the Germans love their recessed hex plugs (at least that’s what’s on my 74) and there is just not enough room for my hex socket on my 1/2” ratchet to get access that, the ZF flange interferes etc. so here’s what I did: I wizzed off about 3/4” from a 17mm hex wrench (from the long side, won’t be missed), inserted that into the hex head plug and put a 17mm ratcheting wrench on the protruding part. Did the trick.
thought I would share for the next guy