Outboard Mounted Brake Drum/Disc Wheel Hub Interface Dimensions - Truck and Bus
This recommended practice contains dimensions and tolerances for outboard mounted brake drums and disc wheel hubs in the interface areas. This recommended practice is intended for outboard mounted brake drums and disc wheel hubs commonly used on class 7 and 8 commercial vehicles. Included are SAE J694 mounting systems II, III, IV, XIV, and X. Special and less common applications are not covered.
Rationale: This document is currently under a five year review. The object of this document is to establish dimensional standardization within the interference areas of outboard mounted brake drums and hubs for disc wheels. Inch dimension tables have been added to this document where metric mounting system tables are referenced. In Tables 1 and 3 a maximum “E” dimension has been added. All other design parameters remain unchanged except for conversion to English dimensions and rounding. Figures 1 and 3 have been revised to show the wheel backup diameter “G” as a reference dimension per SAE J694. Other changes were general formatting.