Bf 6

[tony501]

Hi I change the engine and gearbox oil every year .this year when I drained the gearbox ther were sings of water in the oil very milkey. Which seal should I replace thanks tony

 

[jgmo]

Hi,
There are probably 7 ways water can enter the gear case.

1. Propshaft seal
2. Vertical shaft seal
3. Shift shaft seal
4. Oring for shift shaft seal holder
5. Oring for oil drain screw
6. Oring for oil fill screw
7. Crack or defect in case

A competent shop will have a way to introduce approximately 10 psi air pressure into the case to identify leaks.

Often, there's more than one leak.

Guessing where the leak is has a high probability of being wrong.

But, if that's what you want to do, I would start with the propshaft seal.

Just my opinion.

Good luck.