11.FINAL REDUCTION/ TRANSMISSION SYSTEM UXV 500 TOOTH CONTACT After backlash adjustment is carried out, the tooth contact must be checked. Pay attention to the following procedures: Remove the driven bevel gear. Clean and degrease several teeth of the drive and driven bevel gears. (1) Apply a coating of machinist's layout dye or paste to several teeth of the driven bevel gear. Install the driven bevel gear. Rotate the rear propeller shaft several turns in both directions. Remove the driven bevel gear and inspect the coated teeth of the drive bevel gear. The tooth contact pattern should be as shown in (1), (2) and (3). If tooth contact is found to be correct (example (2)), then to complete installation. (2) (1): Incorrect (contact at tooth top) (2): Correct (3): Incorrect (contact at tooth root) If tooth contact is found to be incorrect (examples (1) and (3)), the shim thickness between the drive bevel gear and driven bevel gear must be changed and the tooth contact rechecked until correct. Make sure to check the backlash after the tooth contact has been adjusted, since it (3) may have changed. Adjust the tooth contact and backlash until they are both within specification. If the correct tooth contact cannot be maintained when adjusting the backlash, replace the drive and driven bevel gears. Tooth contact Drive bevel gear shim adjustment Driven bevel gear shim adjustment Contact at tooth top Increase shim thickness Increase shim thickness Contact at tooth root Decrease shim thickness Decrease shim thickness 11-9