Ring Gear – 60 Teeth – 171.5 mm ID x 199.5 mm OD x 48 mm W. WORKMASTER-65 TRACTOR – TREM 3A 11/10 01/15. WORKMASTER-55 TRACTOR – TREM 3A 01/10 11/17. WORKMASTER-45 TRACTOR – TREM 3A 01/10 12/16.