leaking gearbox

[Malcolm Davenport]

would any Moggy owners have any ideas about about a anoying oil leak in the rear of the gearbox on the right hand side looking down the traveller, its always had a steady drip since i bought the vehicle last September, but after putting it on ramps the oil poured out,all the filler and drain bolts are tight, there is a plate on the side of the gearbox with a wire ajustment, whats the function of this, and the split pin in the gearbox casing which appeares to have been put on from the inside of the box.
any ideas please! :

[bmcecosse]

I can't see why putting the car on ramps would make the gearbox leak.......... The split pin is there to keep that drain hole open - it 'jiggles' up and down - hence it's called the jiggle pin! If oil is coming out of there it's almost certainly the rear main bearing on the engine that is leaking - due to excessive pressure in the crankcase and/or worn bearing shells. If the gearbox is leaking from the rear seal (where the prop shaft exits the box) then the rear bearing and/or seal will be damaged. Does the gearbox oil level go down ?

[taupe]

BMC

I always wondered if there was a name for that split pin, my MG has one too! and now I know

Malcolm

If it leaked when you tipped it up at the front it could be the rear gearbox oil seal

[chrisryder]

if it leaked when you tipped it up at the back, it could be the scroll in the little cover that goes around the first motion shaft in the gearbox. the scroll only turns oil back into the gearbox when it's turning, so when it isn't, it doesn't do much!

if it was leaking out of that cover then the oil would come out of the jiggle pin hole.

if the oil is black it's probably coming from the engine. if it's like fresh oil then it's probably box (unless you've just changed the engine oil!)

[Malcolm Davenport]

Thanks for all the replies, they were helpfull, now i know what the jiggle pin is, this traveller had a new engine 5 years ago and new gearbox 2 years ago, i am going to drain the oil out of the gear box this week-end, give the gearbox a wipe down and refill and see were the leak is.I changed the oil in the engine just before Christmas,and its still on the mark on the dipstick. could this be the resut of overfilling the gearbox, the oil leaking out is clean and fresh.

[bmcecosse]

It's not really possible to overfill the gearbox...... It can only be filled to the level plug.