Over-Center Preload Torque

Loosen adjuster screw lock nut. Back off adjuster screw until stopped, then turn in 1 full turn. Rotate input shaft from stop to stop counting number of turns. Turn shaft half way back to center position.
Attach an INCH lb. torque wrench to input shaft. Turn shaft from side to side through specified arc on each side of center. See OVER-CENTER PRELOAD chart. Note torque reading going over center. See Fig 1 .

OVER-CENTER PRELOAD INCH LBS.

Application

Arc

Over-Center

⁽¹⁾ Total

New Gears

20°

6-10 (.7-1.1)

Used Gears ⁽²⁾

20°

4-5 (.5-.6)

⁽¹⁾	Total preload is sum of thrust bearing and over-center preload.

⁽²⁾	In service for more than 400 miles (640 km.).

Fig 1: Adjusting Over-Center Preload Adjust thrust bearing preload before over-center preload.