Part of the Kubota Repair Manuals.
This is the factory Kubota Workshop Manual for the ZD21N-EC, ZD21-EC, and ZD28-EC ZD Series zero-turn mowers, a 253 page PDF for owners and independent mechanics. It covers the D782-E-XFM5 and D1105-E2-ZD diesel engines together with the transaxle, front axle, hydraulic system, electrical system, and the rotary mower deck.
Each section is divided into Mechanism, which explains how the system is built and works, and Servicing, which gives troubleshooting, servicing specifications, tightening torques, checking, and disassembly and assembly. That structure lets you understand a system before you take it apart.
Many of the key specifications in this listing were verified against the manual's own pages, so the numbers you rely on are the factory figures. Whether you are rebuilding the engine, servicing the hydrostatic transmission, or tracing a wiring fault, the procedures are here. It arrives as an instant PDF download you can view on any device or print for the bench.
What's Inside This Manual
| System | Pages | Key Topics |
|---|---|---|
| G General | 12-58 | General |
| Engine | 59-137 | Engine Body, Lubricating System, Cooling System, Fuel System, Governor, Tightening Torques |
| Transaxle | 138-177 | Hydrostatic Transmission, Pump and Motor, Check Valve and High Pressure Relief Valve, Control Linkage, Final Reduction Gear Section, PTO System |
| Front Axle | 178-186 | Structure, Front Axle Pivot, Front Wheel, Wheel Bracket, Tightening Torques |
| Hydraulic System | 187-201 | Hydraulic Circuit, Hydraulic Pump, Hydraulic Control Valve, Valve Adaptor, Lift Cylinder, Mower Linkage |
| Electrical System | 202-236 | Wiring Diagram, Starting System, Charging System, Battery, Safety Switch, Gauges |
| Rotary Mower | 237-253 | Power Transmission, Lifting Mechanism, Mower Blades, Gear Box, Pinion Shaft, Tightening Torques |
Quick Reference Specifications
| Specification | Value | Page |
|---|---|---|
| All Models | ||
| Fuel tank capacity | 30 L (5.8 U.S.gals., 4.8 Imp.gals.) | p. 9 |
| Front Tire Pressure | 207 kPa (30 psi) | p. 27 |
| Rear Tire Pressure | 140 kPa (20 psi) | p. 27 |
| Engine Oil Filter Cartridge Replacement Interval | Every 200 hours | p. 24 |
| Valve Clearance (Cold) | 0.145 to 0.185 mm | p. 68 |
| Mower Blade Screw Torque | 98.1 to 117.7 N·m | p. 244 |
| ZD21N-EC, ZD21-EC | ||
| Engine crankcase capacity (ZD21N-EC, ZD21-EC) | 3.5 L (3.7 U.S.qts., 3.1 Imp.qts.) | p. 20 |
| Maximum Gross Power (SAE) (ZD21N-EC, ZD21-EC) | 15.7 kW (21 HP) | p. 9 |
| ZD28-EC | ||
| Maximum Gross Power (SAE), ZD28-EC | 20.9 kW (28 HP) | p. 9 |
| Engine Crankcase Capacity, ZD28-EC | 3.4 L | p. 9 |
| D782-E-XFM5 (ZD21N-EC, ZD21-EC) | ||
| Cylinder Head Screw Torque (D782-E-XFM5 (ZD21N-EC, ZD21-EC)) | 37.2 to 42.1 N·m | p. 80 |
| D1105-E2-ZD (ZD28-EC) | ||
| Cylinder Head Screw Torque, D1105-E2-ZD (ZD28-EC) | 63.7 to 68.6 N·m | p. 81 |
