Well, I finally got around to rebuilding the the GR2100 transmission, three times!
Yes, the case has a lip to keep the seal in. So the transmission has to come apart to change the axle seals. The seals sit inside a metal carrier. It turned out to be a good thing in my case. (no pun intended) The RH shaft drive was worn and about to split. It looks like the oil passage was blocked with sealer. This must have been from the warranty recall work done at Kubota (around 200 hours ???) when the axles first started leaking. That was the repair that udated the axle from plastic bushings to bearings. Fortunately all the parts (axles, drive shaft, bearings, etc. come with the T/M kit.
The first time, I had everything apart, cleaned, mostly fitted. I did not have every part in when I test fitted. My bad. I honestly did not expect so many problems with the brand new transmission case. The Bevel Gear from the HST unit did NOT fit through the transmission case. I had to clean off all the gasket maker and hone out the opening in the case for the gear. I also had to (slowly) file open up the hole for the Intermediate Shaft. They were both too tight-the case halves would not mate. Both times I wasted a lot of time and gasket material. I was using the Permatex Anaerobic sealer.
The second time, I got it back together, let it cure for two days, then filler her up. A LEAK. AHHHHH. I was worried about it leaking. The casting for the tramsmission case was poor. I had to take it all apart again. I cleaned off the gasket again. The permatex gasket was hard--plastic-like. It was reletively easy to clean off. This time, I also used brake cleaner to make sure all traces of oil were removed.
Third time-I used a fine arkansas sharpening stone (new, long, flat) to polish all the rough mating surfaces on the transmission housing. I also ordered the Kubota gasket maker. I reassembled and let it cure three days. Filled her up. I saw a minor leak overnight (a 2in spot on the floor). I attributed it to spillage when filling. I mowed all looked good. It has sat for a week. NO LEAKS.
My wife is calling it the zipper tractor because of how easily I can get it undressed. I am hoping it will last this time. I use it to cut and collect ~1 acre of bermuda grass around the house. When it runs, it is a nice mower. It only has 650 hours. I have the bagger and snow blower too. The people that bought our house in MA did not think they needed a snowblower. Ha. But they were smart not to buy the GR. It broke down six months later. The blower is on a moving dolly. If there is any chance of snow in the forecast, I wheel it out as face it north as a totem to ward off the snow god.
Tricks, comments, and mods:
I removed the T/M beam with glide steer cables attached as a unit. (Remove cover, unhook springs, remove 4 bolts.) This allowed me to avoid having to adjust the glide steer linkage when I put everything back together. Those clips are a pain in the blank to remove/install. Or, I just don't have a clue how to use them--likely.
I cut drinking straws to lenght to match the adjustments for the PTO linkage. Much easier than getting a caliper in there to measure.
I added a fuel shut valve before the first fuel filter. (5/16") This will make it easier when I change the filters.
The Kubota gasket maket is an unobtainium (proprietary??) three bond product. I could not find a direct source. At Kubota, it is, of course, twice the price of Permatex 51813 but I found it thicker and easier to work with than the permatex.
I could not figure out how to use the string trick to make sure the oil passage way was clear. When I had it assembled, I blew compressed air through the vent tube. It exited through the oil filler tube opening. So, finfers crossed that the passage is open.
I wrapped hydraulic hoses that looked like they might rub with plastic wire loom and zip tied them.
I got a new tool for the job-an electronic 3/8" torque wrench. The T/M bolts are only tightened to 5.8 to 6.5 ft-lbs. I had nothing that calibrated that low. Another thing to hang by the bench.
I added a weather tight cigarette light ciruit on the rear fender. I will use it for when I pull the sprayer that runs on 12V or charge my phone while I mow.
Oddly enough, I can't wait for the weekend to mow with it....