I have an oil leak from gearbox

[SvMinor]

Ive noticed a small drip of oil coming from the hole in the btm of the gearbox which a split pin is hanging from.
I know there is no oil in this part of the gearbox so why is it in there and should I block up the hole,how can this be rectified.

Cheers Mark

[cadetchris]

the input shaft oil seal could of gone, or the engine is leaking oil into the gearbox.

kinda important you find out what is leaking, as you dont want oil getting on your clutch plate

as for the little hole, its ment to be there to drain any excess oil or water from the bell-housing. blocking it up will cause oil or water to pool in the bell housing and mess up the clutch plate.

[bmcecosse]

Don't block it! Almost certainly oil coming out the rear scroll of the crankshaft -caused by pressure in the crankcase. What's the engine breather arrangements??

[SvMinor]

ill check later at work at the mo.i think its jus normal set up.because I remember you suggesting before that I get a different carb.(was that to cut the oil pressure down)I havent got the other carb yet.

[bmcecosse]

Well yes - to cut down the oil FUME pressure - in the crankcase.

[SvMinor]

Forgive my ignorance but what part of the engine is the 'scroll' and how do I stop the oil leak.
Would I need to get the crankshaft oil seal modification kit that B Moitf supply?

Will I need to pull the engine out again, this is doin my head in, (engine out engine in engine out etc etc)

[aupickup]

if its a small drip i would not worry about it
it is possible its a breathing problem
the oil seal modification is a waste of time and money dont bother with that

[bmcecosse]

It should be controllable by getting decent breathing - the rear end of the crank is 'sealed' ( ) with a scroll on the crank tail which runs in a labyrinth - part on the main cap and part on the little half-moon on the backplate. That should be adjusted down to make sure it's centralised when any work is done on the crank - in practice - there's little that can be done with it. Many have reported that the fancy seal is no good - it would certainly be an engine-out job and requires the crank tail to be machined smooth and round!

[cadetchris]

this is exactly my problem, can we have a picture of this scroll please, would certainly help when i am under the car tomorrow

[SvMinor]

The crank was replaced with a recon 1 from Bull last year,

Whats involved with getting good breathing?

And if I get the breathing sorted will my oil pressure gauge be null and void

[Declan_Burns]

I fitted the OB real seal on mine about two years ago and it's fine. There are however a few tricks involved as that seal does not run on a machined surface. The work involved is enormous so if you can sort it with the breathing that's the road to take.
Regards

[bmcecosse]

It's not oil pressure that is the problem - it's crankcase pressure - from fumes that escape past the rings into the crankcase. A simple clear (as in 'not blocked') pipe from the rocker cover (or any other breather) to the brass inlet pipe on the side of the later carb IS the answer in most cases - except where the engine is very badly worn of course...........
You can't see the 'scroll' unless you take the crank out - or at least, remove the rear main bearing cap! Which you can't do while the engine is bolted to the gearbox..........

[mike.perry]

[frame][/frame] Crankshaft oil scroll[frame][/frame]Crankshaft without oil scroll
Don't worry about a few drips of oil, it stops the underside of the car from rusting.

[bmcecosse]

Well done Mike - where on earth did you find the pic of the crank with NO scroll?!!

[cadetchris]

that is exactly what my crank looks like,

[alex_holden]

that is exactly what my crank looks like,

Which one?

[mike.perry]

They are both Series MM cranks, the scroll is from the car engine and without the scroll is from the military generator engine which has an oil seal