Disc, Clutch Drive. PART NO: A-RE29788. Replaces AR20327, AR546R Dim A (1)O.D.: 4.625" Dim B (2)Thickness: .396" Dim C (3)Hub Length: .811" Spline Dia1.004". . MODELS: John Deere TRACTOR: 70D (7017500- > ) John Deere TRACTOR: 720 John Deere TRACTOR: 730 John Deere TRACTOR: 820(3 Cyl.) John Deere TRACTOR: 830(3 Cyl.) Transmission & Rear Axle > Clutch Disc: Trans and PTO John Deere TRACTOR: 70D (7017500- > ) John Deere TRACTOR: 720 John Deere TRACTOR: 730 John Deere TRACTOR: 820(3 Cyl.) John Deere TRACTOR: 830(3 Cyl.).