Super Major transmisson pressure

[Fixersteve]

Hi Guys, So i have just taken my Super for a 10 mile road run and when i got back to the workshop i have got oil coming out of the high/low selecter where it sits on the gearbox. Also when I unscrewed the transmisson filler cap it hist with pressure. Is this normal, if not whats causing it??

Cheers
Steve


Untitled by fixersteve, on Flickr


Untitled by fixersteve, on Flickr


Untitled by fixersteve, on Flickr

[BearCreek Majors]

your transmission vent is probably missing, in the wrong hole, or pluged with gunk. it is a tall looking bolt on I belive the front fuel tank mount or the rear battery tray mount, I'll have to look next time I'm out in the shop.

Pat

[chriss]

had same thing on "rusty" just took out the tallest bolt under tank carrier and drilled hole out, no problem since, suprising the amount of pressure that builds up

[henk]

It's a common thing. I had it also this year. Cleaned up the bolt and fasten the bold of the plate. The one behind the lever was a bit loose. I have a road run tomorrow, so I will see if it's gone.

[super6954]

Hi Steve
You might find that the lever starts to leak sometime soon after figuring out the breather nut . There is a small lip seal in the housing behind the high low lever they either split or go hard with age and the oil splashing up leaks out round the shaft .

I have had so many leak that I change the seal during restoration as a matter of course now, to be 100% sure it wont' ruin the new paint . If you have oil coming out the housing joint gasket did you remove and replace this gasket to on restoration .All the gear box cover gaskets are thin paper and over the years the housings seem to get a bit loose and mess those gaskets up. you might have to pull the housings and fit a new gaskets/ silicone seal them and change the lip seal at the same time .

Glad to see you got her running, I've been following your work from the side lines of the forum for a fair while it sounds like a major from your video on tube
Regards Robert

[AdrianNPMajor]

Viscosity of oil creates resistance. Similar to friction, energy absorbed from the turning gears to overcome this resistance creates heat. The resultant expansion in the sealed gearbox has nowhere to go, hence the provision of a vent bolt. These often get blocked or painted over.

I've got Morris AG90 in my gearbox and after some serious work the walls of the gearbox housing get very warm. Perfectly normal.

Best

Adrian