In regards to Bob F's post earlier on condensation in M

There doesn't seem to be many ways to seal the shifter ( getting a car type shifter boot that will slide down tight on the shifter and zip-tie or hose clamp the top tighter is one way ) but has anyone tried to seal the cover bolts with soft copper washers or flat rubber washers? The split lock washers would have to be removed. Is there enough movement/vibration of the cover that would cause these to fail quickly? The rubber probably wouldn't be a good choice due to the torques required on the bolts . I wouldn't want to use silicone around or under the heads of the bolts just because it would be a pain to clean up at a later date or wouldn't seal properly trapping more water under the head of the bolt. Just some thoughts. ...Randy

The transmission cover bolt holes are not open ended into the transmission so nothing gets into the gear lube from water in the bolt head depression. Looks are deceiving.
There is a lot of open space in the housing so water vapor condensation is the biggest factor.

You are right. I had my M open to put new bearings in last winter and I THOUGHT I remembered at least two holes open ( one on each side ) to the inside just behind the differential bearing carrier opening. I guess not. There are holes in the belt drive area that are open to the inside which is why the two long bolts have copper washers on them . At least mine did when I took it off. I didn't put it back on so I didn't buy the " gasket " ( part # 29573 ) the parts book calls for so I don't know what they are made of. The gas tank makes a pretty good shield for them though. The other paths water can take is through the filler opening unless it's sealed with Teflon tape each time it's closed and the biggest culprit which has already been mentioned - the shifter. Seems like the rear frame has such a large volume of open space the expansion of the heated air has to go someplace so there's a way for it to get out and equalize the inside and outside pressures otherwise the seals would leak as pressure builds and vice-versa. I'm no rocket scientist but I know water gets into my rear frame and I have to drain it out once or twice a year. How it gets there is the million dollar question. ...Randy

I put a boot for a Ford or Ferguson on my H gearshift down against the spring and have had no more water in the transmission. I got it at TSC.

I like your thinking and it made me think!
When it starts to rain the trans/dif case are all probably 10 or more degrees warmer than the rain and weather front air. As the case cools, the water on the shifter, and other places possible, are sucked on by the contracting cooling air in the housing as it cools. I do believe condensation is also a factor, as many shedded tractors have water in the case. JimN