Hi Tom,
Thanks for comments and I apologize for the delay in getting back to you. My computer took a dump and I've been without for some time. It looks like we share the same problems with this mower's wheels. I finally traced the problem with the front wheels to bad bearings. I haven't been able to update my post, but I will shortly. The front wheel gears strip-out because the defective bearing allow the metal gears to slide around inside the wheel. The metal gears that are attached to the bearings move vertically and horizontally and get out of sync with the plastic wheel gears. When that happens, the metal gears tear-up the plastic gears until they sync-up again. I went to a mower repair shop and picked up a set of new bearings from one of their junk mowers and that did the trick.
As far as the rear wheels, I've never had a problem with those. However, I picked up a spare set from the same junk mower just as a precaution. The AG and Sears have turned a deaf ear to all of this. Sears did send me a $100 gift card to try to appease me, but I couldn't use it at their parts store to get the parts I needed. So I bought some stuff I needed at my local Sears store and shredded my Sears credit card I've had since 1974 and sent the pieces to them with my last payment.
Sears knows there's a problem, but won't own up to it. The AG has bigger fish to fry and doesn't want to step on any corporate feet who might be friends with our Governor. Long story short, I give Sears 5 years or less and they'll be out of business. They can't keep screwing their customers over and stay around for long with better competitors out there.
I hope that helps. Let me know how you make out with the front and rear wheels.
Tom G.