I cannot believe that they didn't use a 2 piece slip shaft with a bolt or a pin that when removed would allow the shaft to be shortened and easily removed.....too much work involved to replace a plastic HST fan or the alt/water pump fan belt. Seems everyone is complaining about something that should take 30-60min to do, and Kubota does nothing to fix engineering issues like this is sad.....
The older G series mowers has a spline at the front of the shaft, where it connected to the engine. This was so that the shaft could move a little while the rubber engine mounts could deflect a little bit. The problem is this: The spline needs a grease fitting on it so that the spline doesn't wear itself out. The fitting is a bear to get to. Nobody ever greased it, it gets rusty, wears out and next thing you know they're cussing & carrying on about how much of a pile of feces design it is. But you could change a fan on them without removing the engine, at least on some of them.
There is a lot more than just adding a slip joint in the middle so you can change the fan. Then you also have to add a support of some sort, with a bearing. Two or three more places for failure-not to mention the additional cost to manufacture and then theres also the extra money that's paid in at the time of purchase that would go into the warranty repair pot. That's how warranty works. The tractor might only have a build cost of $5000 for example, but since they have to stand behind the product, they add in another, say, $1500 to the purchase price, and that $1500 goes to warranty repairs. Some people need all $1500 and then some, others need none. The bean counters have this stuff figured out; and all manufacturers do the same thing, whether it be a car/truck, airplane, or push mower. While in the subject of warranty, I'm going to go out on a limb and say that 80% of "warranty" claims are not in fact "warranty"-they're many times results of neglect, abuse, or use of the machine in such a way that it was not designed to be used, that kind of thing. But the dealers-and manufacturer-bend over backwards to make sure you're satisfied, within reason. Every tractor comes with a warranty statement booklet and I think 98% of people wipe their butt with it after taking a dump and flush it-and that's about the most use it gets. You would be surprised how many times I get the call that this problem should be under warranty-when it states right in that green and white book that his particular problem is NOT warrantable (great example: pick up and delivery and service calls). Read that booklet. There's some good information in there; but I think some folks know that the info inside is "not what they want to hear", and chunk it in the trash.
Back to engineering issues. Have you worked as an engineer? It's a catch 22 process. Design it so it's easy to work on, and it ups the cost. And makes it more complex. And makes more failure points. So in order to make it less problematic in the long run for MOST owners, it's a solid shaft with zero failure points other than the fan. And that fan is the ONLY thing that cools the HST as there is no oil cooler on these little tractors. No place for one really, not without adding tubes, hoses, changing up the radiator, again more failure points, more expense, and more stuff for people to gripe about. The B series has all of it, but it costs more and is a little bigger. Something else for owners to gripe about. We all want a full featured baby tractor because it's manuverable and cheap, but when the time comes to have to work on it, we all (even the techs) gripe about how hard they are to work on. The whole process from the drawing board to production is really interesting. It's not a simple, "hey lets put something together and sell it"....I think I could possibly design one, but it would weigh 45,000 lbs, be 29 feet long, 18 feet high, 12 feet wide, and cost $90,000. But you could work on it and it probably would not break. But who's gonna buy it when X manufacturer has the exact same thing, that looks 10x better, smaller, lighter, more maneuverable, and costs $11,000?