water leak, frost plug (follow up from yesterday)

Obviously the fellow before me had neglected his PM on this machine, but it still leads me to the question: how can a gallon (or any significant amount, for that matter) of water get into the transmission case?

If it frees on heating, ice is about all it can be.

Heres a theoretical question: how long does it take for 1 gallon of water to seep through the gap between a shifter and the case, from nothing more than precipitation?

Assuming (wildly) that hole for the shifer is 1.5" diameter, and a clearance betweeen the shifer hole and shifter of .05" (sloppy loose), that gives a total cross sectional area of (3.14*.75^2)-(3.14*.725^2)=.116 in^2. If the tractor is home to the Lincoln, NE region (where I live), it sees an average of 27" of rain per year. A 27" tall column of water * the cross sectional area of the gap (.116 in^2) would give a total volume of 3.127 in^3 of possible water seepage per year (not considering driving rain or ice buildup and meltage). One gallon of water = 231 in^3, so 231/3.127=73.8 years.

Now, my estimation of the total water is just a guess, and could be off as much as 30% I suppose, leaving an error somewhere between 51 years and 95 years, but the tractor is only 57 years old. I can only assume that the transmission oil had be changed at LEAST once in its lifetime, and strictly based on numerical average it would have been at the 1/2way point in its life, 28 years ago. So, since by my calculations its unlikely that water could enter at a rate fast enough to accumulate a gallon of water, either the gap is bigger that .05", its rained much harder that average during its lifetime, there is another hole where water can enter, or the tractor was at one time an experiment in submarining.

Comments?

This is a very unimportant question.

Water gets in, you keep it drained.

Shifter boots don't help.

Assuming the cavity is 30 gallons, and you exchange 5 gallons of air per day through thermal cycling, and you condense half the days of the year, you are getting the moisture out of 900 gallons of air. Assuming further that only half the moisture runs down the case and gets trapped under the oil, you have 450 gallons of air. Of course the moisture condensed out of the air depends on the relative humidity of the air entering the cavity and the temperature drop overnight and in the morning before the air is expelled upon reheating the next day. Any calculations indicate it would be possible to accumulate one gallon of water in just a few years. Operating and heating the oil will not cause much water to evaporate since it is trapped under the oil and the saturation point of water in oil is quite low.

When the water builds up to where the gears stir it into the oil, you start to get real contamination and possible problems.

Most all old tractors will drain a little clear water out of the drain plug first.

Allan

The transmission top plate bolts are another matter. Any water sitting in the wells around the bolt head can drain past a lock washer right into the transmission. A broken or missing bolt is like a rain gauge. Other suspects are bolts which hold umbrellas, toolboxes, rear light, etc. Any of those vertical bolts offer an excellent entry for water if not carefully sealed.

I've taken to packing the hole right under the bolt head with silicone upon reassembly to keep water out.

I seem to have trouble with water. My roof had a nice leak. My well has high iron. My underground (ground = a homogeneous mixture of rock and clay) plastic pipe to the remote hydrant blew a fitting. Now my tractor is retaining water.

*sigh*