Gearbox oil problem

[Apiarist]

Please could someone kindly give an opinion on the following gearbox oil problem?

My wife’s 1968 Traveller had a lot of work done professionally in 2007 but since then has covered only 1200 miles, being garaged for most of that time.

Preparing it for its MOT I thought I would check additional things such as oil levels and greasing etc. Since the car had hardly been used since 2007 I did not expect to have to add too much to the gearbox, but around 1¾ pints went in. If I have the capacity right, this means the box only had ½ a pint in it!!
This assumes that the filler access also serves as the oil level (there’s no dipstick) and that I’ve not overfilled the box.

On returning from the MOT oil was found on the drive where the car had been left for a while. It was obviously fresh oil and so from the gearbox, but not from the prop-shaft end. The oil used was Duckhams 20w50, supplied by the restorer in 2007.

I’m assuming that a certain amount of pressure builds up in the box when driven and since I’d just filled it the oil was more likely to be forced out if there’s a failed seal (and more noticeable) than when the level was low.

I’m resigned to having to take the box out but before I do would appreciate any thoughts on what the cause might be and what’s needed to remedy it, so that I have a better idea of what to expect.
I should add that it’s around 45 years since I worked on a car in any detail (and then Fords) and so this is now almost a new experience.

Many thanks

Steve

[bmcecosse]

Well -it either leaked from the front or the back....so if you don't see it at the tailshaft seal where the prop plugs in - it must be dripping from the bellhousing 'jiggle pin'.... Put a bit of old carpet/cardboard under to determine where the oil is going. Just check too that it hasn't somehow overfilled - pop the fill plug out and see if any oil runs out. Unlikely of course - but maybe the car was on a slope when filled?

[Apiarist]

Thanks for the prompt response.

I'm pretty sure it's from the front but when left stationary it almost stops. The oil I mentioned on the drive was significant (not just a drip) and immediately after returning from a run which I'm guessing was forcing oil out as I drove (which ran back slightly from the point of exit, probably the jiggle pin you mentioned) where it collected in such a quantity that it was really noticeable where the car was stopped.
So, if the leak is at the front end I assume a seal of some sort has failed and I'm wondering whether this is something that can be tackled by the enthusiastic (sorry, mildly willing) amateur or is a specialist job. Perhaps a replacement box is the way to go but then advice on a reliable source would be needed.

Best wishes

[bmcecosse]

There is no 'seal' as such - just a scroll. Does sound like the level may be a bit high - but also if there is a lot of wear in the front bearing - and perhaps the shaft is not being supported well by the oilite bush (which should be) in the crankshaft tail flange - the oil will be able to run out. 20W50 is slightly on the thin side - it should really be SAE 30 oil - but I doubt that's making much of a difference.

[Apiarist]

Hi, and thanks again.

As the oil level was obviously so low when I topped it up I guess that it was a gradual loss over the 1200 miles covered since 2007 and probably not only when the box was filled, i.e. it was still losing as the level dropped.

However, the other pointers you've given me sound promising and I can now research those before any major work.

Best wishes