Rack-Piston & Worm: Reassembly
- Install "O" ring and piston ring on rack-piston, using care not to twist rings. Install worm into rack-piston, until worm is against piston shoulder. Install 17 ball bearings into rack-piston, while slowly rotating worm counterclockwise.NOTE: Install light and dark colored balls alternately.
Install remaining balls into ball return guide, making sure balls in guide alternate in color with last ball installed in rack-piston. Install guide into rack-piston, install guide clamp, and tighten clamp attaching screws.
- Clamp rack-piston in a soft-jawed vise, with worm shaft up, and install rotary valve assembly on worm such that it engages worm drive pin. Rotate worm until a clearance of 1 1/4" exists between rack-piston and thrust bearing face. Install an INCH lb. torque wrench on input shaft, and note torque required to rotate shaft through an arc of 60° in either direction. Torque with worm rotating should be 1-4 INCH lbs. If rotational torque is not correct, install next larger size ball bearings to increase preload, or next smaller size balls to decrease preload.
- Remove valve assembly from worm. Remove rack-piston from vise. Insert suitable arbor tool into plug end of rack-piston until it contacts worm shaft. Apply pressure to tool while rotating worm shaft out of rack-piston. Leave tool in place until piston is installed in housing.