Farmall A AV Transmission Question

simpsonc9 · Jan 4, 2011

This is what I found when I removed the transmission cover off of my 1945 Farmall AV. I haven't drained any of the fluid yet, is the level supposed to be that low or should it be covering the gears? I imagine some has leaked out over the years.

Now I am wondering what I should do next because of the surface rust that is on the top of the gears, do I need to tear down the entire tranny or can I just clean it off somehow.

That being said what would work best to clean this? I was also wondering what the gears are supposed to look like, and if it looks like there is too much wear on them or if they still look ok. The teeth on one of them look rough on the top edges, is this normal or is there something wrong with it?

Any help would be greatly appreciated!

Farmall%20Transmission%20-%2003Jan11%20%2812%29.JPG

Farmall%20Transmission%20-%2003Jan11%20%2811%29.JPG

Farmall%20Transmission%20-%2003Jan11%20%2810%29.JPG

Farmall%20Transmission%20-%2003Jan11%20%289%29.JPG

Farmall%20Transmission%20-%2003Jan11%20%288%29.JPG

I was also wondering if the casing is supposed to be like that where the arrow is or if it is broken?

Farmall%20Transmission%20-%2003Jan11%20%287%29%5B1%5D.JPG

Janicholson · Jan 4, 2011

Gears that rusted will be a liability. They could be cleaned up, but they would be pitted and wear other gears. I would replace the ones showing that much rust. The casting is good (If I remember correctly the channel is for lubrication of the bearing) from splash. Jim

LMack · Jan 4, 2011

I would make my decision based on how much you have to spend, how much you plan to use the tractor, and how willing you are to clean it up. If this is not going to be a work tractor, the gears will get very little use in the future. Clean them up, clean the transmission, put in new oil and use the old gears unless money is not a factor. However if you plan to actually work the tractor on a regular basis replace the gears. Many of the old tractors that have been sitting for a while will look like that or worse before they are moved or run. The wear show is from trying to mesh the gears with the transmission spinning (gear grinding). All the old tractors will have gears that look like that.

Wardner · Jan 4, 2011

Rust forms in a "cellular" sort of way. After cleaning, you may find that enough of the original contact surface area remains so that the gear is serviceable for light use.

I would clean the rust with a small needle scaler at low pressure. Pack the area with oily rags or paper to retain the rust. Pick up the crud with a magnet. If no scaler, use steel wool. Meanwhile I would create an eBay alert on those gears and the ones below. Buy a cheap set and put them on the shelf in case you need them later. I think a high quality epoxy filler might work to fill pits.

Oil level is determined by the check oil level plug on the side of the casting.

Wardner · Jan 4, 2011

By the way, nice pictures.

LarryT · Jan 5, 2011

I had a spare transmission that did that. I took a high speed dremel and brushed the teeth clean with a wire brush and then used a real fine sanding disk and drum to finish polishing it out. Then I actually used gun bluing on the surface. Not as good as a nitrite repair but the last time i opened that transmission it looked as good as new and that tractor is run everyday. We use it for pulling and the last 6 years pulling a massey 126 baler. Hope to help. LarryT

Haas · Jan 5, 2011

The oil level does not cover the gears. There is a plug behind the brake rod on the LH side of the transmission housing that is the oil level. Fill until it comes out at that opening. It takes 5 quarts of 80-90W oil. The gears and bearings are lubed as the gears sling the oil up and into channels in the housing. That oil runs down and lubes the bearings. If you are just using the tractor for show and don't plan on hard work, I'd just clean the gears up and rinse out the housing with solvent, put in new oil and you should be good to go. The gear teeth are rounded on the ends from the factory to make it so they will go into mesh easier when changing gears. Of course there is some wear, but your transmission looks normal except for the rust.

gene bender · Jan 5, 2011

haas has it clean them up flush the case with some diesel put new 90wt and use it. Now if we had 200hp running full loaded 20 hrs a day different deal. Lots are out there running in worse shape than yours.

Farmall A AV Transmission Question

simpsonc9

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Janicholson

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LMack

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Wardner

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Wardner

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LarryT

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Haas

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gene bender

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