Overview
ISO 7707:1986 - Commercial road vehicles - Connections for rear-mounted power take-offs (PTO) - specifies the essential dimensional characteristics and basic designation of rear-mounted power take-off (PTO) connections for commercial vehicles. The standard defines three connection types (Type A, Type B and Type E) and applies to all installations of PTOs mounted at the rear of transmission gearboxes. Figures in the standard illustrate shapes and reference quantities; dimensions are given in millimetres.
Key topics and requirements
- Scope and types: The standard covers three PTO connection types (A, B, E). Type A is recommended where the vehicle transmission design permits; Type E is permitted for staged (étagées) PTOs.
- Essential dimensions: ISO 7707 specifies the critical mounting and interface dimensions for rear-mounted PTOs to ensure interchangeability and correct mechanical fit. Illustrative drawings provide reference measures and mounting layouts.
- Fastening and hole patterns: Example data in the standard include tapped-hole patterns for certain types - for example, Type E shows an 8-hole tapped pattern (M10 x 1.5) with the option to omit two adjacent holes to allow space for a speedometer drive.
- Spline/interface data: Spline geometry and profile parameters are specified or illustrated (for example, a normalized module of 3.0 and a pressure angle of 20° are referenced for spline details). The standard indicates that detailed spline dimensions (number of teeth, head/primitive/form diameters and depths) are provided in the drawings.
- Designation: The document gives an example designation format (e.g. “Connexion pour prise de puissance arrière ISO 7707-A”) for identifying connection types in technical documentation.
Applications and who uses it
ISO 7707 is primarily used by:
- Vehicle OEMs and drivetrain designers - to ensure PTO mounting compatibility with transmission gearboxes.
- PTO and accessory manufacturers - to design standardised flanges, splines and bolt patterns for rear-mounted PTO units.
- Fleet engineers and upfitters - when specifying or retrofitting PTO-driven equipment (pumps, compressors, winches).
- Aftermarket suppliers and maintenance teams - for selecting replacement PTO interfaces and ensuring correct installation.
- Regulators and standards committees - for harmonising technical requirements across vehicles and markets.
Benefits include improved interchangeability, reduced engineering rework, safer installations and easier aftermarket support.
Related standards
- ISO 7706 - Vehicles - Commercial vehicles - Mounting clearance volumes for power take-offs (referenced by ISO 7707 for installation space requirements).
Keywords: ISO 7707, PTO, power take-off, rear-mounted PTO, commercial road vehicles, transmission gearbox, PTO connections, ISO 7706.