Bevel Gear Tooth Contact Inspection
Reference: TRANSFER ASSEMBLY DISASSEMBLY AND REASSEMBLY
- After cleaning tooth surface of bevel gear (1), paint them with gear marking compound evenly by using brush or sponge etc.NOTE: When applying red lead paste to teeth, be sure to paint tooth surfaces uniformly. The paste must not be too dry or too fluid.
- Install transfer output retainer assembly referring to TRANSFER ASSEMBLY DISASSEMBLY AND REASSEMBLY .
- Turn transfer output flange clockwise and counterclockwise repeatedly, and remove transfer output retainer assembly and bevel gear shims from transfer assembly.
- Bring painted part up and check contact pattern referring to the following chart. If contact pattern is not normal, readjust or replace as necessary according to instruction in chart.NOTE:
- Be careful not to turn bevel gear more than one full revolution, for it will hinder accurate check.
- If bevel gear back lash and bevel pinion shims are adjusted properly, correct tooth contact should be provided.
If correct tooth contact is not provided even when they are adjusted properly, however, there may be an abnormal condition in worn tooth, transfer case or retainer. Check each component and replace as necessary.
GEAR TOOTH CONTACT TABLETooth contact pattern Diagnosis and remedy Normal High contact
Pinion is positioned too far from the center of drive bevel gear.- Decrease thickness of bevel pinion shim and position pinion closer to gear center.
- Adjust drive bevel gear backlash to specification.
Low contact
Pinion is positioned too close to the center of drive bevel gear.- Increase thickness of bevel pinion shim and position pinion farther from gear center.
- Adjust drive bevel gear backlash to specification.
These contact patterns indicate that the "offset" of reduction driven gear is too much or too little. The remedy is to change the division of the bevel gear shim(s). These contact patterns, located on toe or heel on both drive and coast sides, mean that 1) both pinion and gear are defective, 2) retainer is not true, or 3) gear is not properly seated on transfer case. The remedy is to replace the defective member. Irregular patterns: If the pattern is not oval, it means that bevel gear is defective. High or low spots on tooth surfaces or on the seat of bevel gear are the cause of irregular patterns appearing on some teeth. The remedy is to replace the pinion and gear set and, if the seat is defective, so is transfer case.