This SAE Recommended Practice outlines basic nomenclature in common use for truck and bus drive axle designs. Over a period of years there have been many different designs introduced; however, for this report, only the most common have been selected and only their general construction is illustrated to show the nomenclature of the various parts.

The scope and purpose of this SAE Recommended Practice is to provide a standard pattern or sequence for the manual control of automatic transmissions in passenger cars and light-duty trucks. This generally refers to left hand drive mechanical shift applications.

This report is concerned with factors which affect accuracy of distance indication and speed indication of automotive type odometer speedometers. It is the intent to supply information regarding all items which affect the instrument.

This SAE Recommended Practice is intended as a guide toward standard practice but may be subject to frequent change to keep pace with experience and technical advances.

Figures 1 through 5 illustrate in simplified form some of the more common planetary gear arrangements in order to establish applicable terminology. Figures 6 and 7 provide additional examples that use elements of those gear arrangements. Gear ratio is the numerical ratio of input to output speed.

The following schematic diagrams reflect various methods of illustrating automotive transmission arrangements. These have been developed to facilitate a clear understanding of the functional interrelations of the gearing, clutches, hydrodynamic drive unit, and other transmission components.

Two variations of transmission diagrams are used: in neutral (clutches not applied), and in gear. For illustrative purposes, some typical transmissions are shown.

The following information is intended as a guide to be used for evaluating belt construction, source approval, and quality audit. This recommendation has been prepared from existing literature, including standards, specifications, and data supplied by both producers and users.

These recommendations cover drive layout details and V-belt testing methods, including test layout, pulley diameters, torque loads, and guidance for interpreting test data. The application of these automotive V-belts is to power engine or vehicle accessories that are physically attached to the engine.

This Recommended Practice applies to engine cooling fans up to 2000 mm in diameter with a mounting interface consisting of a pilot hole and a circular bolt pattern. Most of these fans are belt, gear, clutch, hydraulically, or electrically driven.

This SAE Standard defines installation dimensions of industrial power take-offs with driving ring-type overcenter clutches.

Table 1 and Figure 1 give dimensions for power take-offs. For dimensions and tolerances of power take-off flanges and flywheels, see SAE J617 and J620, respectively.

The scope of this document is to provide uniform guidelines for the application of starter motor pinions and ring gears. SAE J543 contains guidelines for the use of diametral pitch gearing. The pinion data shown are based on the Fellows stub tooth system. Refer to ISO 8123, ISO 9457-1, and ISO 9457-2 for module gearing, and corresponding metric dimensions.