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MG MGB Technical - MK I Gearbox ... 3 hole or 4 hole layshaft ?

Hi Guys,

Can anyone tell me how to tell if I have an early 3 hole layshaft or the later 4 hole one without stripping the box ?
This is a non overdrive box....

I thought there was some dates on the box, but cant see them and the box is clean....
anyone know where the numbers are stamped ?

The number by the dipstick is 1361.

Cheers
Mark...
Mark Hester

Mark,
You can pull the side ,inspection , cover off the transmission and check the number on the laygear. If the number is 22H54 it should have the smaller layshaft,0.643", with 3 oiling holes. If the number is 22H931 it should be the larger layshaft,0.668, with 4 oiling holes. Hope this is some help.
Tony
Tony Shoviak

Thanks Tony,

Only problem is...
I've not run this gearbox for several years....
But remember breaking the cluster gear and having it replaced.
instead of using needle roller bearings, it has a brass bush pressed into the cluster... presumably as the inner roller surface was damaged.

Thus...It could have any cluster, as it has a custom brass bush....
I used the box for several years in my GT, but it was very noisy in 1st gear, as it was not a matched gear set.... Parts are hard to find in Perth....


Any other way of telling ???
Cheers
Mark.
Mark Hester

I had my old 3-sync gearbox brass bushed by a 'specialist' who didn't know what he was doing - the bearing seized after about a mile and span the leyshaft in the casing, and a week or so later the leyshaft snapped due to the odd loading on the oiling holes. Brass bushes don't work properly without pumped lubrication!

If you remove the front cover, you should be able to measure the diameter of the leyshaft where it pokes out of the main casing.

hth,
--
Olly
Oliver Stephenson

Hi Olly,

Yes, I know its a cheep fix.
I want to do only one race with this gearbox... but I'm thinking that it may not be up to the challenge.

Mark Hester

from what i understand it was only the early boxes that were 3 bearing and was changed for the gt car
ste
Ste Brown

This thread was discussed on 21/03/2007

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