I have a problem with oil going from the front part of the differential, driveshaft end, to the rear ring and pinion side. After looking at my Clymers and calling a top notch BMW mechainc i found it was said there is a seal between the two but he sorta let it slip that the seal is not the problem but rather the screw in piece that holds the seal is leaking around the threads. Long rant i know but this guy is known to know his stuff. I got into my tool box and the tool i use on 4X4trucks fits the screw in piece just fine but i need the tool that holds the pinion still so i can remove the nut to get everything apart and to re torque things when i'am done. He said he would do this for $60.00 but i like to do things where i can. Anyone have or know where i can find this tool.