6 Speed Gearbox

[Paul Richards]

Looking to cure an oil leak on a 6 speed box. I am fairly certain that it is from the gasket where the lid fits on top. It is an alluminium top as opposed to a steel one on a type 9 5 speed.

Is there a breather hole in the alluminium top?

Are there any springs etc. likely to fly out when I take the top of the 6 speed?

Is the gasket the same as the 5 speed?

Any other tips?

 

Paul Richards

Area Representative - L.A.D.S. (Lancashire and District Sevens)

LADS Website

Growing old is compulsory - Growing up is optional

[rj]

Are there any springs etc. likely to fly out when I take the top of the 6 speed?

 

No

 

Is the gasket the same as the 5 speed?

 

No

 

Early gearboxes had an O-ring. Later have been sealed with some kind of... sealer...

[Milesk]

You may want to check the breather is the correct way round - if facing forwards oil can be pushed out in odd circumstances.

 

A little oil can be spread a long way.

 

Prop shaft seal is most common - oil can be flung everywhere. I speak from experiance

 

Good luck

[rj]

Not all gearboxes have breathers.

[Paul Richards]

Thanks for responses so far. This is an early 6 speed g/box and therefore may well have an O ring.

Is the O ring reusable or is it likely to have expanded?

Assume O ring is a large one - the size of the gearbox top?

Assume O ring is available fron Caterham - would I be best to get a new one anyway?

 

Paul Richards

Area Representative - L.A.D.S. (Lancashire and District Sevens)

LADS Website

Growing old is compulsory - Growing up is optional

[rj]

I've removed the lid of mine many times to fill the gearbox and to check the level - never replaced the O-ring.

 

I would guess that it has not been placed correctly, otherwise it's hardly stressed.

 

I don't know if CC supply it. Otherwise Road and Race probably could.

 

I can source it from one of my local suppliers (in Denmark), but I'd have to buy 50 or so because of the minimum buy they have.

[rj]

Oh, sorry

 

The O-ring follows the edge of the lid.

 

And if you have a leak either the mating surface or the O-ring will be damaged.

[simonpa]

It's very unlikely to be the top-plate, but if it is, then at least that can be fixed in-situ :)

 

The breather often leaks, especially if there is no tube on it - you can get to this if you remove the tunnel cover.

 

Changing the rear seal (standard Ford type-9 gearbox, if you can't get to CC) either means engine/box out, or move the diff/prop back (possible, but fiddly).

 

Are you sure it's gearbox oil? Dry-sump tower leaks can spread all over the gearbox :(

However, changing yhr conning tower O-rings is a doddle!

 

HTH - Simon

 

 

 

[Paul Richards]

Guys

Thanks for your comments. It's definitely gear oil and it's a wet sump car so no oil tank in the bell housing.

Leak is similar to one I recently had on my 5 speed and that was cured by renewing top plate gasket. I think the oil was under a little pressure caused by the gears wizzing round and the breather was blocked by paint.

At least I can remove the top to have a look without too much trouble.

 

Paul Richards

Area Representative - L.A.D.S. (Lancashire and District Sevens)

LADS Website

Growing old is compulsory - Growing up is optional