[Caseguytoo]

Yes, you can weld "something" together to lock both wheels together but you will be sorry if you do so. When you are on slippery ground, your tractor won't want to turn because both wheels want to drive it straight ahead. When mowing the lawn, you will tear up your grass every time you change direction. Welding up the spider gears eliminates the differential action of the rear end.

If your tractor can't find traction, then solve the problem by loading the tires, adding wheel weights, putting chains on the tires, switching to Ag tires and so forth. Even the guys in the pulling game rarely weld up spider gears any more.