Single rail box - scroll oil "seal"

[sparky_spit]

On the hunt for a gearbox oil leak, I took the bellhousing off my single rail box/J Type OD. I expected to find an oil seal for the input shaft in the back face of the bellhousing. But no, there is a scroll fitted and not the later type oil seal. Obviously an earlier bellhousing has been used with a later box?

Can I change this by knocking the scroll out and fitting the later type seal? Or will I need to get a later type bellhousing? If the latter, I'll probably keep the scroll equipped one, as time is getting short now, but I thought I'd ask in case it was a quick job and a seal can just fitted in place.

[Nick Jones]

I think some of the early single rail boxes still used scroll seals (certainly you can't easily swap bell housings between single and three rail).

I'm afraid I don't know the answer to your question though - I suspect you can swap them but I think you'll need to knock out the whole scroll housing (including the spigot that carries the clutch release bearing) and swap that for a seal type one.

Surely someone can come up with a whole bell housing for beer money?  Proper seal is definitely more oil tight!

Nick

Edit, Note that the bottom bell housing securing bolt should have a copper washer on it as it goes through into the gearbox and WILL leak if it does not..... don't ask how I know that....

[Doug Paterson]

My 78 Spit has a scroll seal too - was surprised by that when I was changing the box.

You can't fit an oil seal type shaft if you have a scroll type bellhousing.

Second the comment re copper washer on bottom bolt ..... I'd never have spotted it but a certain Mr Doig from Fife tipped me off when I was collecting my new gearbox.

[piman]

Hello SS,

check the oil level is not too high and that the breather is clear, that may be why it leaks. Otherwise make sure the scroll is clean?

Alec

[sparky_spit]

I've done some more digging.... As Doug P mentions above I can't just fit a seal type bellhousing; the input shaft would need to be changed too, so I'll keep the scroll as this is too much work at this late stage.

The oil level was never too high, although It wouldn't take much for it to be; the level plug is only just below the level of the scroll.

The bottom bolt copper washer is fine - the previous builder used blue Hylomar on the washer as an added precaution.

The breather being clear is debatable; there was quite a lot of crap around this which could have blocked it. I'd recommend pulling the plastic top off and taking it apart and cleaning it when you check the oil every time as it would be very easy for the two tiny grooves and exit holes in the breather to get blocked.

Now knowing that I have a scroll "not-seal", I reckon my problem was no more than losing half my gearbox oil into the bellhousing when I had the rear of the car 3 feet up in the air for over a week while I was doing the diff/halfshafts. Because the PO had blocked the bellhousing drain hole with putty (see a previous post) it just collected there knackering the clutch friction plate until I poked a screwdriver in the hole. The small leak I have from the selector shaft hole in the top of the box is minor and I can live with that.

Thanks for the replies guys.

[JensH]

blue Hylomar is a good add, as the original bolt (bottom one, with copper washer) was original a wedglok bolt (i.e. having a cut with nylon in eliminating the use of a spring washer to keep it tight).

[Pete Lewis]

advantage of a scroll  it cant wear out, there's no contact, but yes they leak on hills and even leaked on production lines where inclines were used
the small bleed hole in the top cover from the selector shaft bore is a breather, normally to allow trapped oil to escape from the selector bores as it could put a hydraulic block on gear changes , the cure was to just let it out,( not just triumphs)  Pete