80 series GXL Turbo - Gearbox leak/breather issue

[DaveHDJ80]

Vehicle is 80 series turbo diesel GXL. Only had it 7000kms or 5 months.

I have noticed oil sprayed underneath vehicle on passenger side.

Checked Transfer case/diff and oil was full. Drain and refilled with new oil and checked plugs.

Checked gearbox and was low - drained and only 2.2L came out - meant to be 2.7L.

Inspection shows that there is a very small crack that i can just bit a finger nail into on the flange of the filler for the gearbox. There is also what apears to be some chemi weld/plasti bond type repair under the filler flange.

I think the oil leak has only just started after a 1200km run I did last week.

I degreased underneath, and put a little RTV silicone around the crack. running around town I can feel a little oil on my finger if i inspect it when stopped.

Any idea how such a crack would occur? its extremely neat - like a cut.

How do these gear boxes breath? Pressure must have built up considerably on the long run for it to throw that much oil out this tiny crack.

It does not drop when parked.

Cheers

[silver fox]

There should be a breather on the top of the box near were gear stick mounts to box, there is also a breather on the top off the transfer. The only time I've seen filler plugs crack is when they are over tightened. hope this helps.

[80's_delirious]

there is a breather tube that comes out of the top and goes up into the engine bay behind the engine.

Oil will seep out through a crack wether there is pressure or not,a gearbox will have oil splashing and spraying around inside from all the rotating parts, capillary action takes care of the rest. Silicone wont help something like that