Transmission oil for super


There is around 8 liters of oil in the tranny of my super major. Don't know what it is but looks ok.
I have a lot of 80w90. Gl4. Would it hurt anything topping it off with that?
There are a couple of leaky seals, so am a bit worried that 15w40 will leak more. And I don't have 30 liters of that.
The tractor is mostly used in summer. 20-25 Celsius.
There is only one problem that I can see about using 80/90W. If there is a leak, where is the oil
going? One of the main leaks on Majors is between gearbox and rear axle/hydraulics, not a problem
when the oil in both is the same but Super Hydraulics may give a problem if run on a mix of

We suffered a bit back in the day with slow hydraulics and sticking valves with 80/90W in both
Supers and the Dexta range due to the small channels and orifices in the Super ram cylinder and
hydraulic system when the oil was cold. This was the reason that Ford changed the oil specs back
in the late 1950's after the introduction of the Dexta with a similar system.

Not saying there would be a problem but just something to bear in mind.

My 1952 Major has the oil transfer problem and has had for many years, I just put a pipe on the
trailer tipping pipe, every so often, and transfer the oil back to the gearbox.
Hey Majorman; Do you remember(I'm sure you do) how to tell if it is the main shaft seal, or the pto seal that is leaking? :)
Can not remember Skip, if we had the problem we would change both. If there PTO one was leaking I would have thought the level would level up in both compartments but if the main shaft was leaking the rear axle level would just keep going up. That is just a quick thought though.
Yes, have thought a bit about that seal between the compartment. But looking at the oils they are a different colour. The rear is yellowish and cloudy. The gear oil is clear brown. Both feels like they have the same viscosity and are oils.

Wouldn't they both be same colour if there was a leak?

Could that rear oil be cloudy because of a bit of water?

[size=18:d8ab1c55c7]Rear oil[/size:d8ab1c55c7]

[size=18:d8ab1c55c7]Gear oil[/size:d8ab1c55c7]
The transmission oil level is higher then the rear end's, so the transmission's oil level will go down and the rear will be overfull with seal issues. The rear end oil always ends up milky from moisture in the Majors. My Super Major even after cover off cleaning and refill and never been rained on had oil turn milky with in a couple of years.

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