Steering System - Power: Overhaul Chevrolet Pickup K3500

Disassembly

1. Mount steering gear in vise, clamping onto one mounting tab. Pitman shaft should be in a vertical position. Insert punch through housing access hole to unseat retaining ring. Pry retaining ring out of groove in housing.
2. Rotate stub shaft counterclockwise to force housing end plug from housing. Remove seals and ring. Using Rack Piston Arbor (J-21552) and socket, remove rack piston end plug from rack piston.
3. Remove side cover bolts. Remove pitman shaft nut and spring washer from lower end of shaft retaining pitman arm. Remove pitman shaft and side cover assembly. Remove pitman shaft adjuster screw lock nut. Remove pitman shaft cover. Remove gasket from side cover.
4. Remove pitman shaft lower dust seal and rubber boot (if equipped). Using snap-ring pliers, remove pitman shaft lower retaining ring. Remove pitman shaft lower seals and washer. Using Pitman Shaft Bearing Puller (J-6278), remove pitman shaft bearing from housing.
5. Insert Rack Piston Arbor (J-21552) into end of rack piston assembly until arbor seats into end of worm shaft. Threaded arbor will keep recirculating balls from falling out of rack piston. Rotate stub shaft counterclockwise, forcing rack piston onto arbor. Remove rack piston and arbor assembly. Ensure arbor is fully inserted so recirculating balls will not fall out.
6. Remove adjuster plug lock nut. Using spanner wrench, remove adjuster plug. Remove valve body, stub shaft, worm shaft, seal, bearing races and worm bearing assembly from housing. If further disassembly is required, see appropriate component under OVERHAUL.

Reassembly

1. Lubricate components with power steering fluid before reassembly. Install valve body, stub shaft and worm shaft assembly into housing.
2. Place seal protector over stub shaft. Install adjuster plug until it seats against valve body. Remove seal protector from housing. Loosely install adjuster plug lock nut. Insert rack piston (with arbor to retain recirculating balls) into housing. Align worm shaft and rack piston. Turn stub shaft clockwise to engage worm shaft. Maintain pressure on arbor until worm shaft is fully engaged. Remove arbor.
3. Install NEW pitman shaft side cover gasket. Thread pitman shaft side cover onto adjuster screw until it bottoms. Back off 1/2 turn. Install pitman shaft so center sector gear tooth meshes with center groove in rack piston. Install side cover bolts.
4. Install adjuster screw lock nut halfway onto pitman shaft. Install rack piston end plug in rack piston. Install housing end plug seals, ring, end plug and retainer ring. Adjust worm shaft bearing preload and over-center preload. Refer to «WORM BEARING PRELOAD»(ref-55269-S01276736492001011700000) and «OVER-CENTER PRELOAD»(ref-55269-S05022228952001011700000) under ADJUSTMENTS.

Using snap-ring pliers, remove adjuster plug retaining ring. Remove adjuster plug washer and seal. Using screwdriver, pry up bearing retainer at raised area. Using Bearing Remover (J-8524-1) and Driver (J-7079-2), remove bearing from adjuster plug.

Using Bearing Remover (J-8524-1) and Driver (J-7079-2), install bearing into adjuster plug. Install bearing retainer. Lubricate seal with power steering fluid. Install adjuster plug seal, washer and retaining ring.

Note. Retainer projections must not extend beyond washer when retaining ring is seated. Adjuster plug washer must be free to rotate.

1. Mark position of worm bearing races and bearing to worm shaft. Mark position of worm shaft notches to valve body. Remove worm shaft from valve body and stub shaft assembly. Remove stub shaft seal. Remove worm bearing races and bearing from worm shaft.
2. Lightly tap end of stub shaft against wood block until shaft cap is free of valve body. Pull stub shaft outward until drive pin hole is visible. (Scheme 10) CAUTION: DO NOT pull shaft more than 1/4" (6 mm) or spool valve may become cocked in valve body.
3. Disengage drive pin. Remove stub shaft from valve body. Rotate and remove valve spool from valve body. If binding occurs, realign valves. CAUTION: DO NOT force stub shaft or valve spool out of valve body.
4. Remove spool valve seal. Remove valve body rings and seals.

Scheme 10

1. Lubricate valve body components with power steering fluid. Install NEW rings and seals. Lubricate spool valve seals with power steering fluid and install on valve spool. Carefully insert valve spool into valve body.
2. Push valve spool through valve body until locating pin hole is visible at opposite end of valve body, and valve spool is flush with notched end of valve body. Install stub shaft into valve spool and valve body.
3. Align stub shaft locating pin with valve spool locating hole. Align notch in stub shaft cap with pin in valve body. Install stub shaft seal into valve body. CAUTION: Before installing assembled valve body into gear housing, ensure valve body stub shaft locating pin is fully engaged in stub shaft cap notch. DO NOT allow stub shaft to disengage from valve body pin.
4. Install bearing and races on worm shaft, aligning marks made during disassembly. see scheme 1 Install worm shaft onto valve body and stub shaft assembly, aligning notches made during disassembly.

Remove ball guide clamp screws and clamps. Remove ball guides. Remove all recirculating balls from rack piston. see scheme 1

1. Lubricate seals and ring with power steering fluid and carefully install onto rack piston. Install worm shaft into rack piston until worm shaft touches piston shoulder. While turning worm shaft counterclockwise, insert ball bearings into rack piston. NOTE: Ensure light and dark colored balls are installed alternately; Black balls are.0005" (.013 mm) smaller than Silver balls.
2. Install 6 balls in ball guide, alternating ball colors. Bearings in guide must be in sequence with bearings in rack piston. Hold balls in place with chassis lubricant. Install return ball guide assembly into position.
3. Install clamp. Tighten clamp screws. (Scheme 11) Insert Rack Piston Arbor (J-21552) into rack piston until it contacts worm shaft. Maintain pressure on arbor, and back worm shaft out of rack piston. DO NOT allow ball bearings to drop out.

Scheme 11

Disassembly (Model "P")

1. Using Puller (J-29785-A), remove pulley from shaft if not previously removed. Remove union fitting and "O" ring. Remove reservoir retaining bolts. Remove reservoir and "O" rings from housing.
2. Using punch and screwdriver, remove end plate retaining ring. Remove end plate and pressure plate spring. (Scheme 12) Remove "O" ring, flow control valve, and spring. Using soft-faced hammer, tap end of drive shaft to loosen pressure plate.
3. Remove pressure plate, pump ring, vanes, retaining ring, rotor, and thrust plate assembly from housing. Remove drive shaft. Pry drive shaft seal from housing. Remove dowel pins and seals.

1. Lubricate all "O" rings, seals, pump ring, rotor and vanes with power steering fluid. Using socket, press NEW drive shaft seal into housing.
2. Install dowel pins and all "O" rings. Install drive shaft and thrust plate. Install pump rotor into housing with counterbore facing drive shaft side of steering pump.
3. Install NEW drive shaft retaining ring, ensuring ring is seated in groove. Install vanes with rounded edges toward pump ring. Install pump ring and pressure plate. Install "O" ring, flow control valve, and spring.
4. Install pressure plate spring, end plate, and retaining ring. Install seals and reservoir. Install union fitting, "O" ring, and reservoir retaining bolts.

Scheme 12

Scheme 13

Scheme 14

1. Remove pump assembly from vehicle. Remove retaining clips between reservoir and housing and remove reservoir from housing.
2. Remove union fitting and "O" ring. Remove control valve assembly and flow control spring.
3. Protect drive shaft with shim stock and using a small chisel, cut drive shaft seal and remove. Using small drift punch, remove end cover retaining ring. (Scheme 13)
4. Remove internal components of pump by gently pushing on drive shaft. (Scheme 14)
5. Remove "O" ring from pump housing. Remove locating dowel pins. Remove drive shaft seal (if not already removed). Remove end cover, pressure plate spring and "O" ring from pressure plate.
6. Remove pump ring and vanes from drive shaft subassembly. Remove retaining ring from drive shaft. Remove pump rotor and thrust plate from drive shaft.