1955–1960s Oliver SUPER 55HC / SUPER 55 DIESEL / 550 HC / 550 DIESEL Tractor Shop Manual (Injection Pump P/N 1LS1701C)

This shop manual covers 1955–1960s Oliver SUPER 55HC, SUPER 55 DIESEL, 550 HC and 550 DIESEL tractors, including HC gasoline and diesel engines with fixed or adjustable front axles.

• Engine repair: Engine removal, cylinder-head replacement, wet-type cylinder sleeves, piston and connecting-rod work, valve-rotator inspection and timing-gear alignment.

• Diesel fuel system: American Bosch PSB pump timing and internal phasing, injector testing, fuel-system bleeding, energy-cell service and symptom-based troubleshooting.

• Drivetrain and brakes: Tractor splits, traction and independent PTO clutch overhaul, transmission service, differential adjustment, final-drive repairs and double-disc brake service.

• Hydraulic lift: Vickers pump testing and overhaul, internal control-valve service, draft and position linkage adjustments, and remote-cylinder bleeding.

• Steering and front axle: Fixed and adjustable front-axle service, Saginaw manual steering-gear adjustment and overhaul, plus power-steering pressure tests and fault diagnosis.

• Cooling and electrical: Water-pump service, thermostat replacement, Delco-Remy generator, regulator and starter specifications, and ignition-timing procedures.

This manual suits mechanics familiar with tractor splitting and component overhaul; injector testing requires a dedicated nozzle tester.

Engine Repair and Cooling

Engine procedures cover connecting-rod orientation, crankshaft and camshaft inspection, and cylinder-head replacement. Gasoline and diesel timing-gear views (Figs. O667 and O668) show the different gear arrangements.

The bearing sections distinguish hardened crankshafts used after engine serial 961990 from earlier HC crankshafts with different bearing requirements. Those notes help match replacement bearings to the crankshaft before an engine repair.

Cylinder-head, main-bearing and connecting-rod torque specifications accompany the inspection limits. Cooling coverage includes radiator removal and water-pump disassembly; the lubrication section covers oil-pump inspection and replacement of worn pumps as complete units.

Gasoline Fuel and Diesel Injection

Gasoline coverage provides calibration and repair-part tables for Carter UT2257S, Marvel-Schebler TSX603/TSX775 and Zenith 12427 carburetors, together with governor-linkage adjustments. It does not include a carburetor overhaul procedure.

Diesel coverage extends to injection-pump hydraulic-head replacement, governor adjustment, fuel-transfer-pump service and energy-cell inspection. Injector testing addresses leakage, opening pressure and spray pattern, with Bosch centering sleeve TSE773 identified for nozzle assembly.

The manual distinguishes pump-to-engine timing from internal pump timing and phasing. The American Bosch injection-pump exploded view (Fig. O684) identifies the hydraulic head, control unit and governor components involved.

Transmission, PTO and Final-Drive Repair

The six-speed constant-mesh transmission section covers the input double gear, countershaft components, differential bevel gears and bearing cages. Figure O722 shows the transmission assembly; separate procedures address final-drive bull gears, wheel axle shafts and belt-pulley overhaul.

Traction-clutch and Twin Disc SP-505 PTO-clutch procedures cover their respective removal, inspection and adjustment work. The manual warns that moving the hollow PTO pinion shaft over unprotected clutch-shaft splines can damage its internal lip seal.

Differential service notes identify the change around tractor serial 66 750-000, after which the ring gear and differential are supplied as a complete service assembly.

Hydraulic Lift Controls

Manual-selector and double feed-back systems have separate linkage-adjustment instructions. Tractor serial 46001-500 marks the production change to double feed-back; serial 64 218-500 identifies the later relief-pressure configuration. Earlier tractors may have been converted.

Coverage includes the Vickers vane pump, internal pilot and directional valves, hydrostat assembly and optional remote control valve. The internal control-valve sectional view (Fig. O765B) identifies the passages and valves used in the lift system.

Troubleshooting addresses failure to lift, erratic draft control, excessive settling and pump noise. Fluid capacities are listed for the hydraulic reservoir, transmission case and crankcase.

Manual and Power Steering

Manual steering coverage explains Saginaw recirculating-ball gear adjustment, sector mesh and wormshaft end play. The power-steering appendix adds a troubleshooting chart, pump overhaul and Gerotor power-unit service, supported by the power-unit schematic (Fig. O773A).

A specific caution addresses steering-wheel removal: hammering on the steering shaft can damage the power unit's thin thrust-bearing races.

Tractor splitting and work on pressurized hydraulic systems require suitable lifting and support equipment and practical repair experience.

Electrical Specifications and Scope

Electrical coverage distinguishes early 6-volt HC equipment from later HC and diesel 12-volt systems. It provides Delco-Remy generator, regulator and starting-motor test specifications, distributor settings and ignition-timing procedures. Electrical wiring diagrams are not included.

PDF Text Search, Bookmarks and Diagram Readability

This printable, English-language 63-page PDF includes one added cover, 55 main-manual pages and the seven-page power-steering appendix. An existing OCR text layer supports searches on the 62 manual pages, with recognition errors; the added cover has no searchable text, and embedded section bookmarks provide navigation. Small labels in the hydraulic schematics require zooming.