Tractors4U, I was noticing the same thing about the wheels. Thanks for mentioning it. I thought a lot about reversing wheels and went so far as to examine the bearings and shafts and do some calculations. The result was that I did not reverse mine. Yanmar has it exactly right for minimum stress on the bearings and seals. Still, I figure that my neck is worh the possibility of replacing a certain amount bearings and seals. What I finally did was to put on some wheels with an additional one inch of offset to the rim on each side.
Frankly, I would recommend that he leave the wheels like they are. My motivation is entirely selfish!! The reason being that I have always been curious if the bearings would "take it" with the wheels in the reversed position. I would sure be carefulabout big loader loads, though.
Another thought is that his is an older 336, and that particular bearing and seal area did not entirely please Yanmar either since they redesigned the outer bearing and wheel seal a couple of times during the model run until they felt like it was up to absolutely bulletproof standards. The good news is that the redesigned parts will work with the older tractors, though some support pieces have to be replaced as well.
I should emphasize that even with the original old design front bearings and seals I've not heard of any structural problem in any kind of normal use. Which I'm sure does mean with the wheels in the standard position - not reversed. The factory was just being typical Yanmar when they redesigned: making them better and less leaky and stronger all at once.
