This is the official Kubota B21 parts catalog, a 365-page PDF you can download and keep on any device. It covers the B21 compact tractor, with exploded diagrams and Kubota part numbers for every major system: the diesel engine, fuel and cooling systems, clutch, transmission, HST, rear and front axles, brakes, steering, hydraulics, and the full electrical system.
Each section pairs a numbered illustration with a parts table listing the reference number, Kubota part number, description, quantity, and the serial number range a part fits. That serial number column matters on an aging B21, where components changed mid-production, so you order the version that actually bolts to your machine.
Use it to identify worn or broken parts, cross-check numbers before buying, and plan a repair or restoration without guessing.
Complete the set for your B21
- Repair Manual: Kubota B21, TL421, BT751 Shop Manual (incl. Wiring)
What's Inside This Kubota B21 Parts Manual
| System | Pages | Key Topics |
|---|---|---|
| Clutch & Transmission | Clutch, Clutch Rod, Clutch Pedal, Clutch Housing, Transmission Case, Clutch Shaft, HST, 2Nd Shaft/3Rd Shaft/4Th Shaft, Range Gear Shift Fork, Neutral Holder Link, Range Gear Shift Lever, Range Gear Shift Rod, PTO Gear Shift Lever | |
| Fuel System | Fuel Camshaft and Governor Shaft, Idle Apparatus, Injection Pump, Governor, Speed Control Plate, Nozzle Holder and Glow Plug, Nozzle Holder, Fuel Pump, Air Cleaner, Accelerator Lever, Fuel Tank, Fuel Pipe, Fuel Filter, Stop Solenoid, Speed Control Pedal | |
| Cooling System | Water Flange and Thermostat, Water Pump, Fan, Water Pipe, Radiator | |
| Engine | Crankcase, Oil Pan, Cylinder Head, Gear Case, Head Cover, Oil Filter, Main Bearing Case, Camshaft and Idle Gear Shaft, Piston and Crankshaft, Flywheel, Valve and Rocker Arm, Inlet Manifold, Exhaust Manifold, Muffler, Upper Gasket Kit, Lower Gasket Kit | |
| Electrical System | Alternator, Starter, Battery, Switch, Panel Board, Head Light, Hazard Light, Tail Light, Winker Lamp, Electrical Wiring, Working Light Kit, Wire Harness Kit | |
| PTO | PTO Shaft, PTO Protector | |
| Rear Axle, Differential & Brakes | Rear Axle Case, Rear Differential, Rear Axle, Brake, Parking Brake Lever, Brake Pedal, Differential Lock Pedal, Front Axle Case, Rear Wheel | |
| Front Axle & Steering | Propeller Shaft, Front Wheel Propeller Shaft, Front Wheel Drive Lever, Front Axle Frame, Front Differential, Front Axle, Front Drive Shaft, Drag Link, Tie Rod, Steering Handle, Front Wheel | |
| Hydraulics & 3-Point Hitch | Hydraulic Control Lever, Hydraulic Change Rod, Hydraulic Pump, Hydraulic Oil Line, Flow Divider Valve, Hydraulic Cylinder, Control Valve, Hydraulic Outlet, 3-Point Linkage 2, Hitch/Lower Link, 3-Point Linkage 1 | |
| Body & Operator Station | Center Frame, Oil Tank, Bonnet, Panel Cover/Shutter Plate, Fender LH, Fender RH, Seat, Seat Turn Table, Base Seat Turn Table, Seat Adjuster, Step, ROPS/FOPS, Smv Emblem | |
| Decals & Accessories | Label, Accessories and Service Parts | |
| Other Components | Front Shaft, Main Flame, Drawber Kit |
Quick Reference Specifications
| Specification | Value | Page |
|---|---|---|
| FUSE | 50A | p. 142 |
| FUSE AUTO | 5A | p. 142 |
| SHIM INJECTION PUMP Thickness | 0.20mm | p. 41 |
| PISTON Oversize | +0.5mm | p. 30 |
| METAL CRANKPIN Undersize | -0.2mm SET | p. 30 |
| METAL CRANKSHAFT Undersize | -0.4mm | p. 30 |
| ASSY BATTERY | 12V36AH | p. 122 |
| FUSE Rating | 50A | p. 142 |
| FUSE AUTO Rating | 5A | p. 142 |
| BULB LIGHT Power | 27W | p. 133 |
| GEAR CLUTCH SHAFT Tooth Count | 23T | p. 162 |
| GEAR 4WD Tooth Count | 19T | p. 182 |
