This gear and the corresponding outer ring of the first gear synchronizer hub are often worn from the grinding that occurs if first is engaged while rolling. If you are rebuilding a 3-synch with this teeth configuration, this gear will nearly always need replacing. Specification: 13/19/23/26 teeth, for use in stock helical-cut box. Also found in Spridget with rib case gearbox. Ref: 22G1100.