Did a search and couldn't find the info I need on these fittings. I'm new to the "euro" hardware, so perhaps you folks can educate me.

I have a 1981 300D and have a persistent leak on the transmission dipstick "banjo" fitting that screws into the oil pan. The transmission is a 4-bolt pan, 722.118. I have replaced the aluminum seal rings following a filter/fluid change and have a leak that leaves a small puddle on the driveway. You folks have any tricks for stopping leaks on these things? There were no rings on the fitting when I took it apart, but it leaked then also.

Any information is appreciated!

You need to remove it again, or at the next change, and see that all four surfaces are flat and smooth. You can run a flat file carefully over both sides of the fitting and maybe on the transmission. The bolt will be harder to repair if it is not flat and smooth, but if the bolt looks bad, you can get one for not much at the MB dealer. In fact, it might be worth having a new bolt ready the next time you do the change. Dress the other three surfaces, use some new seal rings and a new bolt, and I will bet that it will no longer leak.

Good luck,