John Deere 4020 Transmission Diagram Link

The JD 4020 serial number break is vital here.

[ Engine ] --> (Clutch) --> [ Input Shaft ] | (Constant mesh) | [Countershaft] ----> [ Mainshaft ] / | \ (Gear 1) (Gear 2) (Gear 3/4) | | | [Shift Collars] | | | | [Output to Rear Axle] John Deere 4020 Transmission Diagram