1970–1975 Oliver 1755, 1855, 1955 Tractor Shop Manual (P/N DL-SM-3)

This shop manual covers 1970–1975 Oliver and Cockshutt 1755, 1855, and 1955 tractors, including Rowcrop, short-wheelbase Utility, Wheatland, and Four-Wheel Drive configurations.

• Engine repair: Engine removal, cylinder-head service, wet-sleeve and piston inspection, crankshaft bearings, timing gears, and lubrication-system repair.

• Fuel and governors: Marvel-Schebler carburetor overhaul, diesel troubleshooting, injector testing, Roosa-Master pump timing, fuel-system bleeding, and governor adjustments.

• Drivetrain: Engine clutch service, transmission overhaul, Hydra-Power Drive and Hydraul Shift troubleshooting, transfer drive, differential, and final-drive repairs.

• Front axle and steering: Axle and wheel-bearing service, front-drive planetary assemblies, and Saginaw Hydramotor pressure testing and overhaul.

• Hydraulic lift: System troubleshooting, pump checks and overhaul, draft and position control, lift cylinders, and remote control valves.

• Brakes and PTO: Service-brake and hand-brake adjustments, hydraulic brake-valve service, and independent PTO clutch, brake, and control-valve overhaul.

• Cooling and electrical: Water-pump overhaul, thermostat checks, Holley distributor timing, Delco-Remy alternator and starter test data, and wiring diagrams.

This manual is suited to experienced mechanics who can interpret bearing-preload measurements and hydraulic test results; injector testing also requires dedicated test equipment.

Engine, Fuel Injection, and Turbocharger Service

Engine coverage distinguishes the naturally aspirated diesel in the 1755 from the turbocharged diesels in the 1855 and 1955. Internal repair sections address valve guides and seats, camshaft bushings, piston rings, sleeve projection, and crankshaft inspection.

The Roosa-Master section covers pump removal and installation, drive-shaft replacement, timing, and linkage adjustment. Internal injection-pump overhaul is referred to a specialist diesel service facility. Roosa-Master seal tools 13369 and 13371 are identified for drive-shaft work.

Turbocharger coverage is limited to inspection, lubrication, and removal/reinstallation, with exchange-unit service described for internal faults.

Front-Drive Axle and Saginaw Steering

The front-drive axle cross-section and Hydramotor exploded view support the component service text. Front differential procedures distinguish conventional and No-Spin assemblies, while separate steering-cylinder sections address standard-front and four-wheel-drive layouts.

The Hydramotor reassembly notes address Teflon-ring sizing, where premature installation can damage a seal. Front-hub removal notes also identify the risk of damaging the axle-housing oil seal if the assembly's weight is carried by the axle shaft.

Auxiliary Drives, Transmission, and PTO

Exploded assembly views show the clutch, transmission gear train, and Hydra-Power auxiliary drive during transmission repair. Separate fault lists and pressure-check locations help match a complaint to the auxiliary unit actually fitted.

The transmission lubrication schematic traces oil delivery to the shafts and differential. The dual-speed PTO exploded view clarifies how its gear and shifting arrangement differs from single-speed units.

Hydraulic Pump, Hitch, and Remote Valves

The hydraulic Quick Check combines pump-yoke movement with pressure readings to help distinguish excessive leakage from restricted flow. Further sections cover the compensator, pressure-control and unloader valves, servo valve, and hydraulic oil-cooling circuit.

Category II hitch coverage uses an internal lift cylinder and internal draft-sensing mechanism. Category III coverage addresses external lift cylinders and externally mounted draft springs. Remote-valve procedures distinguish pressure-detent and float types.

Use this technical reference for work involving heavy drivetrain assemblies and pressurized hydraulic systems within your training and workshop capabilities.

Cooling Service and Variant-Specific Wiring

Radiator removal, water-pump assembly, and thermostat inspection accompany the electrical test specifications. Separate wiring diagrams cover the 1755/1855 non-diesel tractors, the 1755 diesel, and the 1855/1955 diesels.

A Sample of Valve Adjustment and Guide Data

These valve-service values are a small selection of the adjustment and inspection specifications in the manual.

For non-diesel engines, the cold intake valve tappet clearance is 0.019–0.021 inch. The same section provides the corresponding exhaust and diesel settings.

For diesel cylinder heads fitted with spiral-groove valve guides, the specified guide inside diameter is 0.373–0.374 inch. The text distinguishes these guides from the plain-end version.

PDF Search, Bookmarks, and Wiring Detail

Finding text and reading diagrams: An embedded OCR text layer supports searches through the workshop text and tables, with recognition errors in places. Wiring-diagram labels have limited text-search coverage. Chapter bookmarks are included, and small wiring labels require zooming.

The download contains one printable English-language PDF with 69 pages total, including one additional cover page and 68 pages of manual content. The cover is already included in the total.