I keep writing up maintenance issues on what used to be my academic blog, but that seems fine to me. There are lots of different kinds of intellectual adventures, and the ones I have these days tend to be mechanical.
I write about what I'm thinking about. If anyone actually wants to read it, they're welcome, but I don't care either way.
The transmission on our old Kubota B6000 sub-compact tractor had frozen again this winter. This has happened a lot. This is because we don't have enough shelter for farm equipment. The rain gets in through the bellows on the gear shift when the tractor is parked outside all summer. Other moisture no doubt arrives courtesy of Maine's sky-high summer humidity.
I had developed the routine of changing the transmission oil before winter sets in, but this did not do the trick this year. I made the mistake of flushing the gear box with some stale gasoline I had. Gasoline doesn't dissolve water, and so some water was left in. It wasn't very much water that got left in. Most was removed with the old oil. But it was enough to freeze one side of the rear axle case solid.
I had to do something. We need this tractor to move snow in awkward spots that the plow truck can't do and to pile up snow when it gets too deep for the plow.
There was a day in the weather forecast predicted for a high of 34 F. I seized the opportunity and put a heat lamp on the tractor gear case 24 hours earlier. Then I drained the old 80 weight out. First a tiny bit of water trickled out. Then the oil. It was green and emulsified. Then I put my heat gun nozzle right on the oil filler with the drain plug out, and ran it for a couple of hours, pumping hot air through the tranny. More water slowly trickled out. Finally, with the tractor still warm, I threw in a couple of gallons of preheated denatured alcohol. I had left it next to the wood stove for a while, still in unopened gallon cans straight from the store, so it was probably at 90 to 100 F or so.
If you try this trick, obviously you have to be careful preheating the solvent. It's highly flammable.
I ran the transmission (by running the rear PTO) with the alcohol in to for a minute or two, just enough to circulate the solvent, but not enough to cause any real wear. Then I drained it out and thriftily put it back in the cans. It was cloudy with suspended oil and what I hoped was dissolved water. I'm sure it will eventually fall clear (like the home-made wine we make) and still be usable for most purposes.
I'm now waiting for the sun to get high enough to make the job of filling the tractor's transmission with replacement SAE 80 more comfortable. It was minus five last night.
The gear oil is next to the wood stove too. It's way too cold for it to flow at the outside temperature. The couple hours needed to get the gear oil up to temp was just enough for me to do some surfing, and then make this blog post.
Then it's back out into the cold to do the job.
Update: The transmission did thaw and the tractor works again, but not without the additional help of a couple hours of heat lamp on the frozen axle. I'm hoping that whatever remnant water was still in there is dissolved now by alcohol and stays in suspension.
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