Minneapolis-Moline M-670 & M-670 Super Tractor Shop Manual 1964–1970 (P/N S-450)

This Minneapolis-Moline factory tractor shop manual (P/N S-450) covers the 1964–1970 M-670 and M-670 Super. It includes the October 1, 1966 factory material for the Super’s independent power steering and dual-speed PTO.

Finding Sections and Reading Diagrams

Index and diagram detail: Use the printed index on PDF page 2 to find sections. Text search and PDF bookmarks are unavailable. The wiring diagrams have readable component numbers and wire-color legends. Zooming in makes the fine lines easier to follow through crowded areas.

The download is one printable English PDF with 204 pages, including one added front page and 29 pages of factory supplementary material.

Engine, Hydraulic, and Drivetrain Service

These selected shop topics illustrate the repair coverage. The manual also includes cooling-system backflushing and accessory drive shaft service.

• Engine overhaul: Compression testing, cylinder-head and valve reconditioning, piston and ring fitting, connecting-rod and crankshaft inspection, camshaft timing, and engine oil-pump overhaul.
• Fuel systems: Gasoline carburetor adjustment and overhaul, LP-Gas vaporizer-regulator testing and repair, and diesel injection-pump timing, bleeding, and nozzle testing.
• Tel-O-Flo and Type E hydraulics: Pressure and pump-flow tests, draft-control and dash-pot checks, spool synchronization, lift removal and repair, and remote-cylinder operation.
• Steering and PTO: M-670 hydraulic steering and standard PTO/belt-pulley service, plus M-670 Super independent steering and dual-speed PTO service.
• Drivetrain and chassis: Engine clutch, Ampli-Torc, sliding-gear transmission, differential and rear axles, brakes, Type E/U/N front ends, wheel bearings, and tractor separation.
• Wiring and illustrations: Separate Diesel and Gasoline/LP-Gas wiring diagrams, starter and charging-system test data, steering and lift oil-flow diagrams, and an exploded view of the Ampli-Torc.

Minneapolis-Moline prepared this manual for its dealers and service personnel. Pressure and flow testing, precision measurement, nozzle testing, press work, and tractor separation make it best suited to experienced mechanics with a properly equipped shop.

Choosing the Right Section

Sections 2 and 16 cover the M-670’s hydraulic steering and standard PTO/belt pulley. Sections 2A and 16A cover the M-670 Super’s independent steering and 540/1000 RPM PTO, including pump and hydramotor repair, bleeding, PTO clutch and brake adjustment, and teardown and inspection. The separate steering tests help you choose the pressure reference for the system fitted to your tractor.

The manual also distinguishes Pierce and Hoof governors, early and later Tel-O-Flo lift components, and the later high-speed cooling fan. Fuel- and altitude-specific cylinder-head and ignition-timing charts identify the applicable head by part number.

Fuel-System Service and Injection-Pump Limits

The gasoline procedures distinguish fixed and adjustable load jets. LP-Gas coverage includes carburetor overhaul, strainer service, leak checks, and vaporizer-regulator adjustments.

Diesel coverage includes filters, Roosa-Master pump removal, installation and timing, nozzle opening-pressure, leakage, dribble and spray-pattern tests, and energy-cell removal and installation. The manual directs internal overhaul of the sealed injection pump to an authorized Roosa-Master service station. It identifies the flange marks as pump calibration references and warns that changing pump timing with the engine running can damage the pump.

Lift Diagnosis, Drivetrain Setup, and Shop Tools

Tel-O-Flo coverage explains three-point lift operation, traction amplification, temporary raise, rate-of-drop control, back-flow and relief valves, rockshaft service, and fault isolation. Type E coverage addresses single- and double-acting remote cylinders, kick-out operation, filtration, and valve adjustment. The hydraulic-pump section supplies dimensions and a parts list for a pressure-test adapter when a flow meter is unavailable.

The drivetrain sections give bearing preload, torque, clearance, wear-limit, and capacity data. They cover separation at the engine-to-transmission and transmission-to-differential joints and explain when the differential and rear axles can be serviced with the tractor intact.

Identified shop tools include steering needle-bearing installer 10T5178, clutch bushing driver and alignment tool 10A12741, Ampli-Torc wrench 10A12802, transmission seal sleeve 10A12739, and bull-pinion seal sleeve 10P2644.

Repair Cautions

The engine clutch is balanced as an assembly, so the pressure plate and back plate retain their original alignment during reassembly. The Ampli-Torc section identifies the upward-facing cam-cage oil hole as a lubrication requirement.

The work involves pressurized hydraulics, escaping LP-Gas, high-pressure diesel spray, and heavy assemblies. Follow the manual’s precautions for supporting and lifting the tractor, relieving pressure, isolating fuel, and protecting yourself during testing.

Sample Steering Pressure Specifications

With the oil at operating temperature and the steering at its stop, the M-670 hydraulic steering test specifies 950–1,050 psi at 1,800 engine RPM. For the M-670 Super’s independent steering, the corresponding test specifies 1,250–1,275 psi at 1,000 engine RPM.