Farmall A diff oil and capacity?

Hi just fixed the trans/diff oil leak on my 1945 farmall A and im goin to change my trans,diff fluid. Does anyone know what type of oil is used or what would you recomed, and how to get it to the proper level. im sure there is some kind of plug , but if anyone knows that would be handy, also would it help to maybee add any kind of additive such as lucas or something. it does wine somewhat but i guess thats to be expected with straight cut gears. any help would be greatly appreciated. also what engine oil weight would you recomend. I live in missouri. screwy weather almost everyday. THANKS

80W90 gear lube is fine. No additives needed. Although, of all the additives, Lucas is one of the better products out there. Most ones on the market are snake oil. I will have to look up the capacities of the tranny and the bull gear covers on the final drive for you......unless someone else has them handy.

The 80-90 gear oil is fine. Drain plug for the tranny is on the right face, at the lower rear, behind the diff shaft housing. Fill level plug is diagonally opposite, a short distance up on the front of the left face and much smaller. Usually a square head pipe plug, the brake actuating rod will be a little in the way of a wrench when removing and replacing it. As for capacity, 5 qts for the tranny, figure on another half quart if you have a pto/belt pulley. That unit will also have a drain plug. My practice there is to drain both and refill through the fill plug on top of the pto, as all the excess will drain right down to the tranny. If it takes significantly less, you can figure you've got a lot of sludge inside and may want to think about cleaning it out.

If you want to do the final drives, as ws mentioined below, that will involve dropping the pans on the bottom of each. Its the only way to drain them and you might just as well plan on new gaskets for them. Refill on each side is three pints, delivered through a hole with a large pipe plug found just fore of the cap over the inner end of the axle on each side.

As a gentle suggestion, I'm gonna recommend you spring for an Owner's Manual if you plan to run this tractor. It will answer many of the real basic questions about operation and maintenance.

As for motor oil, the stuff has advanced so since the oils available when the Owner's Manual was original, that that is one point where it is obsolete, so I'm gonna say it's your preference. It's been hashed over MANY times here. Some favor 10-30, others 10-40, some swear by straight 30 (detergent/non-detergent is a whole other discussion). Some run nothing but the same 15-40 they put in their diesels. Each has his own reason for choosing the oil he does, with variables like weather and use factoring in, but I haven't heard anybody complain of wearing their motor out for using the wrong oil. Regular changes of oil and filter will be more important no matter what weight you use.