1975–1978 Ford 420 3-Cylinder Tractor Loader Backhoe Parts Catalog

This parts catalog covers the 1975–1978 Ford 420 tractor loader backhoe and includes a separate Ford 765 industrial backhoe parts section. Numbered illustrations connect components to part numbers, quantities, application notes and kit contents.

• Engine and fuel: Parts breakdowns for the cylinder block, head, crankshaft, pistons, Holley carburetor and rotor injection pump, plus cooling-system components.

• Drivetrain and brakes: Transmission cases, gears, clutches, PTO assemblies, rear axles, differential-lock linkages and brake controls, with reference-numbered parts lists.

• Hydraulics and steering: Pump, lift-cover, control-valve and steering-cylinder illustrations identify internal components, seals, linkages and related pipes.

• Electrical equipment: NHNA and NH-E harness layouts, starting motors, alternators, lamps and instrument-cluster parts, identified by illustration callouts.

• 765 backhoe: Boom and dipstick assemblies, swing posts, hydraulic cylinders, control valves and lever-control components, with separate attachment parts tables.

• Chassis and equipment: ROPS rollbars, cab mounts, Super Comfort seats, drawbars, hitches and wheel weights, including their attaching hardware.

The catalog suits mechanics and owners who can match an illustrated assembly to the equipment fitted to their tractor before selecting parts.

Parts Lookup and Repair Scope

Application notes distinguish components shared across several tractors. Those model references apply to individual assemblies; they do not make this a complete parts catalog for every tractor named.

This is a parts reference for repair planning and ordering. It does not provide step-by-step overhaul procedures or diagnostic test routines, and exploded views do not establish a safe disassembly sequence.

Engine, Fuel and Cooling Parts

Gasoline and diesel tables separate cylinder heads, pistons, manifolds and engine gasket kits. The 420 diesel replacement-block entry calls for FP115 and FP575 stepped-stud kits when an earlier block is replaced with the listed E6-level unit. These notes help match the replacement block and its hardware before ordering.

Fuel-system drawings distinguish Holley carburetor components from rotor-type injection equipment, with single- and dual-filter assemblies and dry-type air cleaners. Radiator and water-pump listings identify cooler and pulley variations.

Transmission, Steering and Hydraulic Assemblies

The torque-converter sections separate the case, oil distributor, pump, clutch and gear assemblies. Manual reversing and conventional manual transmission drawings have their own tables, alongside PTO components and reduction gearboxes listed by ratio.

Steering-gear lists identify shims and seals. Brake linkages, the transmission handbrake and differential-lock controls appear as parts assemblies; hydraulic-lift pages distinguish cover controls, shaft linkage and cylinder components.

Remote-control valves, coupling kits and accessory cylinders have separate breakdowns. Their component descriptions support parts selection, not hydraulic pressure testing.

Electrical Layouts and Instrument Parts

Regional and cab-specific illustrations show harnesses, switches, lamps and their mounting hardware. These are component-location drawings, not circuit schematics with connector pinouts.

Instrument-cluster replacement notes identify associated sender changes. That distinction matters when matching a replacement gauge assembly to the tractor's existing equipment.

765 Backhoe and Optional Equipment

The backhoe section separates two-lever and four-lever controls and their conversion parts. Lift, crowd, bucket, stabilizer and swing-cylinder tables identify rods, pistons, packing and seal kits, with separate figure groups for different swing-cylinder designs.

Equipment pages distinguish swinging drawbars, automatic pick-up hitches and the Series 796 quick-attach hitch, with separate stabilizer and rear-wheel-weight kits.

Cab coverage includes mounting parts and lower panels; detailed cab components are referred to a separate Industrial Cab Catalog. The ROPS section cautions against installing seat belts on tractors without rollover protection.

Selected Wheel-Hardware and Valve-Seat Sizes

These examples show a small selection of the catalog's component dimensions and hardware specifications.

The front-wheel table lists hub bolts measuring 1/2"-20 x 1-3/4". Its hex-flange nut entry specifies a 1/2"-20 thread for D8NN1007BA and D5NN1007A wheel assemblies.

For the 420 diesel engine, exhaust valve-seat inserts are listed in .010-inch (.254 mm) and .020-inch (.508 mm) oversizes. These are replacement-part sizes, not wear limits.

The hardware-conversion appendix excludes tapped holes and mixing metric and inch threads; mismatched threads can damage fasteners or housings.

Figure Search and PDF Section Bookmarks

Finding parts and reading illustrations: Text search works in parts tables and figure headings; illustration callouts are not searchable text. Eight bookmarks open the main sections. Small callouts in dense illustrations are easier to read when enlarged.

One printable, 601-page PDF contains 508 pages for the 420 catalog and its index, 73 for the 765 catalog and its index, 14 pages of abbreviations and two pages of hardware conversions. The total also includes one preliminary page, one figure-search guide and two blank separator pages.