After years of use, the wheels on my Heavy Duty Shop Fox mobile base are falling apart. I installed this base in 2001 under my LT18 bandsaw, and have used it since then with no problems. Now the wheels are basically falling apart; the actual wheel itself. Anyone else have this issue, and if so, are there replacement wheels available? Looked in the Grizzly catalog, since they sell the SF mobile bases, but no replacement wheels. The swivel mechanism is working fine; just the actual wheel.