F-12 Transmission ???????

Dave Allgire · Nov 14, 2017

I restored, excuse me, rehabbed this tractor in 2006. It's an F-12 with a #90 plow. I had sandblasted all parts, new seals, bearings throughout, block decked, head redone, crank reground, new gaskets, new tires, paint, decals, etc. I installed all new fluids, filters also. When I drained the transmission, it was like tar. OK, so I cleaned it out with diesel fuel. I installed 80-90 SAE gear oil. Today I removed the transmission top cover because of too much gear lash for the belt pulley. Going to take care of that. Surprise, surprise! I now have a light rose colored, maybe light pink, fluid in the rear end. Indicates water right? So how did IH seal the top cover from the factory to keep water out? Put the tractor together and then paint everything? And that was enough to keep water from getting in around the cover bolts? Some of the bolts go all the way through to the interior of the transmission. Do I need to seal these bolts with Permatex or "gasket maker"? Frustrating to say the least. I'm open to ideas, suggestions, etc.

Janicholson · Nov 14, 2017

There is about 50% of the volume of the housing that is air. When the temperature changes from day to night, ans seasonally, that air expands and contracts quite a lot. (maybe 2 Quarts of air with 25 degrees change in temp. As it cools, it sucks in air to fill that volume. as it does, it drags in moisture which condenses on the cold metal and contaminates the oil. In the past when these tractors were tillage and daily workers, the oil was heated from friction and viscous shear to warm to hot levels. This drives out the water. What can be done is to heat the trans periodically to mimic the work. or drain and heat the oil in separate containers (safely). Jim

Dave Allgire · Nov 14, 2017

Respectfully sir, I don't necessarily agree with you. I didn't get any water out of the transmission when I drained it originally. I understand your way of thinking but, there is no "vent", per se, in the transmission cover. You have to remember this unit has sat for numbers of years without being used, moved, exercised. So if this is a "sealed" unit, I don't see where the moisture is getting in. My way of thinking is there are entry points of moisture, ie rain, that is getting in around the lock washers of the mounting bolts and maybe the gear shift lever. I think I would have to seal these entry points with gasket maker to keep this from happening. Your thoughts.

Janicholson · Nov 14, 2017

The case of the trans/final drive is far from sealed. Though the bolts in the top are moderately waterproof due to the contact with the deck, plain washers (not lock washers) can improve even that. The moisture (and volume of air that transports it as vapor) gets in through the shifter shield and tower, as well as all axle and bearing seals (which keep oil in, not air out). Heroic effort has been made to seal all platform bolts and put boots over the shifter by Forum members. The efforts all do little for prevention of water accumulation. The old oil (tar like goo) probably had a chemical reaction with moisture and bacteria to become as it was. New 90wt has water dispersants in it that suspends water as a milky brown as you have. It only takes a cup of water to do that. If left for a month in warm weather, the water usually will separate and collect in the sump. I have drained gear boxes in construction equipment that has been inside for its whole life with gallons of water in them. Farmalls with 3 gallons of H2O in freezing temps will not move, yet it will have been stored inside. Jim

RBoots · Nov 14, 2017

Jim is right, most of these old tractors don't have dedicated vents on the rear end/transmission cases, but the moisture goes on and out everywhere. When it's sweating on the outside of the transmission in springtime, it's sweating on the inside too. A lot of tractors will leak around the bolts too if left setting outside in the rain frequently.

Dave Allgire · Nov 15, 2017

Well, at this point I guess I'll let it sit until next summer and then drain the water out. And yes it does sit outside under a car cover year round. I like the idea of the flat washers under the bolt heads. And I'm going to try and seal any/all bolts that penetrate the transmission housing. I know that won't solve everything but my peace of mind. Thanks for the replies.

James Williams · Nov 15, 2017

Dave, if I remember correctly those F series had a gasket around the top plate, and it was like a black tar type of gasket, or at least one of mine did. I also think 90 weight is a little thin. The original was around a 200 grade, basically like tar

F-12 Transmission ???????

Dave Allgire

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Janicholson

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Dave Allgire

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Janicholson

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RBoots

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Dave Allgire

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James Williams

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