John Deere 450D/455D Bulldozer & Loader Technical Manual, 1983–1987 (P/N TM-1291)

John Deere Technical Manual TM-1291 (Oct-87) covers the 450D Crawler Bulldozer and 455D Crawler Loader. The October 1987 complete revision corrects artwork and service text for the steering-pedal configuration. It provides machine-specific repair and system testing; Deere’s separate Fundamentals of Service manuals supply general theory.

Bookmarks and Text-Search Limitations

Search, navigation, and diagram detail: Embedded OCR is unreliable across much of the PDF. Section and procedure bookmarks aid navigation, although the electrical schematic bookmark opens its legend; the diagram is on the preceding page. Small wiring labels require zooming, and five pages display upside down and need viewer rotation.

One printable, English-language 906-page PDF, including the front and back covers, a one-page revision notice, and 65 blank or header/footer-only pages.

Undercarriage, H-L-R Drivetrain, and Equipment Repair

These are selected topics from the manual, which also includes fuel-storage guidance and cold-weather starting-aid service.

• Undercarriage and final drive: Track-chain, master-pin, roller, front-idler, recoil-spring, and hydraulic-tensioner service; final-drive disassembly and bearing adjustment.

• Transmission and steering: Transmission removal and installation, H-L-R clutch-pack overhaul, countershaft repair, steering clutches, brake bands, and lever-steer or pedal-steer adjustments.

• Engine repair: Crankshaft, camshaft, timing gears, connecting rods, pistons, liners, cylinder head, valves, oiling system, turbocharger, and cooling-system repair.

• Hydraulic repair and testing: Loader, dozer, winch, and backhoe pumps, control valves, and cylinders; pressure, flow, efficiency, and drift tests.

• Attachments and equipment: Multi-purpose buckets, lumber/pulpwood forks, 6405/6410/6415 blades, powershaft/winch drive, 9300/9550 backhoes, ripper, drawbar, and log arch.

• Electrical and machine diagnosis: Seven-step fault-finding method, operational checkout, starting and charging tests, electrical schematics, wiring layouts, and hydraulic diagrams.

• Chassis and operator station: Frame, bottom-guard, counterweight, ROPS, and cab removal and installation procedures.

Deere wrote this manual for experienced service technicians; the procedures call for lifting tools, measuring instruments, and hydraulic test equipment.

Track Inspection, Transmission Setup, and Steering

Track inspection includes link-height and pitch checks, bushing-diameter measurements, sprocket and idler wear inspection, upper carrier roller repair, frame alignment, and crossbar removal.

The track-chain procedure warns that hammering out the master pin can enlarge the link bore. The tension-adjuster chapter explains how pulling the piston from the yoke can damage the scraper and piston seals.

H-L-R repair extends into the clutch oil pump, accumulator, oil manifold, shift valve, ring-gear/output-shaft backlash and preload, and cooler/filter assemblies. Related work includes neutral-start adjustment and 1000-rpm powershaft/winch-drive service.

Steering repair includes hydraulic clutch components, brake anchors, housings, and linkage, with separate procedures for the lever-steer and revised pedal-steer configurations.

Engine Internals and Fuel-System Repair Limits

Internal inspection covers bearing clearances, journal taper and roundness, valve-train measurements, piston and liner condition, cylinder-head service, oil-pump inspection, and turbocharger clearances. Related groups address water-pump repair, thermostat testing, starter bench tests, flywheel service, and engine-clutch and pressure-plate repair.

Fuel-system procedures cover injection-pump removal and installation, drive-shaft and timing work, nozzle removal and installation, and bleeding. Internal pump and nozzle repair requires separate manuals: SM-2045 for the pump and TM-1214 for the nozzles; neither is included.

Component-specific torque specifications, wear limits, clearances, spring data, lubricant information, and assembly checks accompany the repair groups.

Attachment Hydraulics and Winch Variants

Loader and dozer chapters detail frame and boom removal, alignment, bucket and cutting-edge repair, control linkage, reservoir/filter service, and selector and flow-divider valves. Return-to-dig operation, valve repair, and adjustment are also covered.

Separate 9300 and 9550 backhoe groups document boom, dipperstick, swing-frame, and stabilizer work, control-valve sections, anti-cavitation and relief valves, and boom, crowd, bucket, and swing-cylinder repair.

Winch work covers clutch and brake drums, gear-train setup, seal testing, free-spool adjustment, and brake-band burnishing. The earlier three-packing and later single-seal clutch-cover designs have separate procedures, helping technicians match repair work to the winch configuration.

System Tests, Circuit Diagrams, and Tool Drawings

Engine tests cover compression, oil pressure, cooling-system leakage, fuel-transfer-pump pressure, and boost. Hydraulic tests distinguish loader and dozer pump configurations and include relief-valve, flow-divider, and cylinder-drift checks alongside H-L-R and steering-clutch diagnosis.

The Electrical System Block Diagram, Electrical System Schematic Diagram, and Wiring Harness Layout support circuit tracing. Power Train Block Diagram, H-L-R Transmission Power Flow, and Main Hydraulic System Block Diagram explain drivetrain and hydraulic operation.

Dimensioned shop drawings support fabrication of the JT38006 Liner Holding Fixture, JT38007 Track Roller Installation Tool, JT38014 Final Drive Housing Lifting Tool, and JT38016 Clutch Housing Alignment Tool.

Because this manual covers pressurized hydraulic circuits, recoil springs, raised loader and backhoe structures, and heavy drivetrain components, the machine must be safely supported and hydraulic pressure released before repair work begins.

Examples of Crankshaft and Bearing Inspection Limits

The main-bearing inspection section lists a new-bearing clearance of 0.04–0.12 mm (0.002–0.005 in.) and a maximum clearance of 0.15 mm (0.006 in.).

The crankshaft end-play limit is 0.38 mm (0.015 in.), with a dial-indicator checking procedure alongside the specifications.