1972-1985 Allis Chalmers 616 620 720 & Pow'r Max Tractor Repair Manual & Parts Catalog

Technical Scope and Service Data

• Covers 1972–1985 Allis Chalmers tractors, including models 616, 620, 720, 4040, 4041, 9020, and the Pow'r Max variant
• Original OEM publication TP 500-0504-01-PM-SA, printed as a consolidated manual containing Volume 1 and Volume 2
• Contains 83 detailed exploded-view diagrams and 3 distinct electrical wiring schematics
• Downloads to your account within seconds of checkout
• Your order stays downloadable from your account for life
• Laid out for standard letter and A4 printing
• Full-text search finds any part number in seconds
• This 120-page manual is the master reference for the hydrostatic and mechanical systems found on the Allis Chalmers 616, 620, and 720 tractor lines

Document Structure and Coverage

Mechanical and System Overviews

This 1972–1985 Allis Chalmers 616, 620, 720 service manual details the repair, disassembly, and maintenance procedures for a range of garden tractors. The content encompasses the two-cylinder air-cooled Onan power units, documenting engine removal, assembly, and timing settings. Chassis maintenance sections address wheel assemblies, drop housing repair, and final drive gear installation. Brake documentation provides linkage adjustment and disc assembly overhaul for the individual, high-capacity systems found on these units. Operators and technicians receive reference on hydrostatic transmission priming, PTO drive unit servicing, and front axle steering gear adjustments.

Specification and Reference Data

The documentation provides extensive technical values including torque specifications for plated hardware up to Grade 8 standards, which lists values as high as 1,000 ft-lbs for specific applications. Electrical reference data is provided via wiring diagrams for the 4040, 4041, and 9020 tractors, alongside testing parameters for the 20-amp charging circuit and 12-volt electric PTO clutches. Hydraulic data documents relief valve settings for the power lift system, noting break-off pressures between 550 and 800 psi. Reference values for understanding factory workshop documentation appear throughout the component sections. The text includes specific shim color-identification charts and critical end-play clearances for transmission and final drive gear settings.

All service data shown here is for reference only — qualified technicians and the original OEM documentation remain the authoritative source for any hands-on work.

An official 120-page Allis Chalmers OEM manual covering the 1972–1985 Allis Chalmers 616, 620, 720, and associated variants, documenting engine, drivetrain, electrical, and hydraulic repair specifications for these classic machines.