Steering Gear Box Explanation

STEERING GEAR BOX DESCRIPTION
The power steering gear is a recirculating ball type gear.

STEERING GEAR BOX OPERATION
The gear acts as a rolling thread between the worm shaft and rack piston. The worm shaft is supported by a thrust bearing at the lower end and a bearing assembly at the upper end. When the worm shaft is turned the rack piston moves. The rack piston teeth mesh with the pitman shaft. Turning the worm shaft turns the pitman shaft, which turns the steering linkage.

STEERING GEAR BOX ADJUSTMENTS
NOTE: Adjusting the steering gear in the vehicle is not recommended. Remove gear from the vehicle and drain the fluid. Then mount gear in a vise to perform adjustments.

STEERING GEAR BOX OVER-CENTER
1. Rotate the stub shaft with Socket (special tool #8343, Wrench) from stop to stop and count the number of turns.
2. Center the stub shaft by rotating it from the stop 1/2 of the total amount of turns.
3. Place torque wrench and Socket (special tool #8343, Wrench) in a vertical position on the stub shaft. Rotate the wrench 45 degrees each side of the center and record the highest rotational torque in this range. This is the Over-Center Rotating Torque.
NOTE: The stub shaft must rotate smoothly without sticking or binding.
4. Rotate the stub shaft between 90° and 180° to the left of center and record the left off-center preload. Repeat this to the right of center and record the right off-center preload. The average of these two recorded readings is the Preload Rotating Torque.
5. The Over-Center Rotating Torque should be 0.45-0.80 N.m (4-7 in. lbs.) higher than the
Preload Rotating Torque.
6. If an adjustment to the Over-Center Rotating Torque is necessary, first loosen the adjuster lock nut. Then turn the pitman shaft adjuster screw back (COUNTERCLOCKWISE) until fully extended, then turn back in (CLOCKWISE) one full turn.
7. Remeasure Over-Center Rotating Torque. If necessary turn the adjuster screw and repeat measurement until correct Over-Center Rotating Torque is reached.

NOTE: To increase the Over-Center Rotating Torque turn the screw CLOCKWISE.
8. Prevent the adjuster screw from turning while tightening adjuster lock nut. Tighten the adjuster lock nut to 37-52 N.m (27-38 ft. lbs.).

STEERING GEAR BOX SPECIFICATIONS
• Steering Gear Type - Recirculating Ball
• Steering Gear Overall Ratio - 14:1 LWB or 16:1 SWB

SPECIFICATIONS - PITMAN SHAFT OVERCENTER DRAG
• Pitman Shaft Overcenter Drag
o 0.45-0.80 + Worm Shaft Preload
o 4-7 + Worm Shaft Preload

STEERING GEAR BOX REMOVAL
NOTE: The steering column on vehicles with an automatic transmission may not be equipped with an internal locking shaft that allows the ignition key cylinder to be locked with the key. Alternative methods of locking the steering wheel for service will have to be used.
1. Place the front wheels in the straight ahead position with the steering wheel centered and locked.
2. Siphon out as much power steering fluid as possible.
3. Position the coolant bottle aside.
4. Remove the steering shaft coupler (Fig 3) #1 pinch bolt at the steering gear #2.
5. Remove the steering shaft coupler (Fig 3) #1 from the steering gear #2.
6. Remove the power steering hoses/tubes (Fig 4) #1, 2 from the steering gear.
7. Raise and support the vehicle.
8. Remove the track bar retaining bolt (Fig 5) #2 at the frame and lower the track bar #1.
9. Remove the pitman arm (Fig 6) #2 retaining nut #3.
10. Using the Ball Joint Press (special tool #C-4150A, Press, Ball Joint) (Fig 7) #1 or equivalent, remove the pitman arm #2 from the steering gear.
11. Remove the steering gear retaining bolts (Fig 8) #1 and remove the steering gear.

STEERING GEAR BOX INSTALLATION
1. Install the steering gear on the frame rail and tighten the bolts (Fig 8) #1 to 118 N.m (87 ft. lbs.)
2. Align and install the pitman arm (Fig 6) #2 and tighten the nut #3 to 265 N.m (195 ft. lbs.).
INOTE: It may be necessary to pry the axle assembly over to install the track bar (1) at the frame rail.
3. Position the track bar (Fig 5) #1 at the axle bracket, install the nut and bolt #2 at the frame rail bracket and tighten to 169 N.m (125 ft. lbs.).
4. Remove the support and lower the vehicle.
5. Align the column coupler shaft (Fig 3) #1 to the steering gear #2. Install a new coupler pinch bolt and tighten to 49 N.m (36 ft. lbs.).
6. Install the power steering hoses/tubes (Fig 4) #1 2 to the steering gear and tighten to 28 N.m (21 ft. lbs.).
7. Reinstall the coolant bottle back into position.
8. Fill the power steering system to the proper level.
9. Check the toe setting.