rudy, I'm a little late to the party, but
I tend to agree with blkwtr, the tires may make a big difference. Have you tried airing yours up a bit above normal to see if that is the problem? The ribbed tires look like they'd help alot with steering. Even tho' my 345 has power steering, it still seems harder to steer than one might think, unless I keep the tires fully inflated. It's also a bit wore.
The wheel on my 345 was a real bear to get off. I hung the tractor by using ratchet straps tied to the steering wheel until the whole thing was picked up off the floor; then smacked the steering shaft with a brass drift and hammer. It popped off with a bang. (the nut was put in place to keep it from flying). Been trying to figure out a method to attach a puller to it, but if it's only once in 20 years, guess I'll live with it. That guy you mentioned should have been forced to leave the company years ago.
It would have so easy to include threaded inserts for removal when molding the wheel; or design the hub for same.
And, I gotta agree about the "meteorologists". With all their charts and graphs, they still get paid too much whether they're right or wrong.