Steering Gear Pitman Shaft Over-Center Preload Adjustment - Off Vehicle 708 Model
- Turn the pitman shaft adjuster screw counterclockwise until the
pitman shaft adjuster screw extends fully. Then turn the pitman shaft adjuster
screw back 1/2 turn clockwise.
- Rotate the stub shaft from stop to stop. Count the number of turns.
- Starting at either stop, turn the stub shaft back 1/2 the
total number of turns. This is the center of the gear.
The flat on the stub shaft should face upward when the gear is in the
center. The flat on the stub shaft should be parallel with the side cover.
- Align the master spine on the pitman shaft (2) with the adjuster screw
(1).
- Place the torque wrench,
with the handle in the vertical position, on the stub shaft. Rotate the torque
wrench 45 degrees to each side of the center. Record the highest
drag torque measure on or near the center.
Notice: Use the correct fastener in the correct location. Replacement fasteners
must be the correct part number for that application. Fasteners requiring
replacement or fasteners requiring the use of thread locking compound or sealant
are identified in the service procedure. Do not use paints, lubricants, or
corrosion inhibitors on fasteners or fastener joint surfaces unless specified.
These coatings affect fastener torque and joint clamping force and may damage
the fastener. Use the correct tightening sequence and specifications when
installing fasteners in order to avoid damage to parts and systems.
- Use the following
procedure in order to adjust the over-center drag torque:
6.1. | Loosen the adjuster screw jamb nut. |
6.2. | Turn the pitman shaft adjuster screw clockwise until the correct
drag torque is obtained. |
- On new steering gears (under 400 miles), add 0.6-1.2 N·m
(6-10 lb in) torque to the worm bearing preload torque.
Do not exceed a total steering gear preload of 2 N·m (18 lb in).
- On used steering gears (400 miles or more), add 0.5-0.6 N·m
(4.5 lb in) torque to the worm bearing preload torque. Do not
exceed a total steering gear preload of 1.5 N·m (14 lb in).
Tighten
Tighten the adjuster screw jamb nut to 47 N·m (35 lb ft).
- Install the steering gear. Refer to
Steering Gear Replacement
- Fill the pump reservoir with the power steering fluid.
- Bleed the system. Refer to
Power Steering System Bleeding
.
Steering Gear Pitman Shaft Over-Center Preload Adjustment - Off Vehicle 710 Model
Tools Required
J 7754-01 Torque
Wrench
- Always check the worm shaft bearing preload adjustment. Adjust the worm
shaft bearing preload, if needed, before performing the pitman shaft over-center
preload adjustment.
- Turn the over-center adjusting screw all the way out clockwise.
Then turn the over-center adjusting screw in 1/2 turn.
- Place the J 7754-01
with a 3/4 inch 12-point socket (3) onto the stub shaft.
- Rotate the stub shaft from one stop to the other. Count the turns.
Turn the stub shaft back to center.
- Check the over-center preload by rotating the torque wrench through
a 180 degree arc on each side of the center. Note the highest readings.
The readings must be 0.8-1.9 N·m (7-17 lb in).
Notice: Use the correct fastener in the correct location. Replacement fasteners
must be the correct part number for that application. Fasteners requiring
replacement or fasteners requiring the use of thread locking compound or sealant
are identified in the service procedure. Do not use paints, lubricants, or
corrosion inhibitors on fasteners or fastener joint surfaces unless specified.
These coatings affect fastener torque and joint clamping force and may damage
the fastener. Use the correct tightening sequence and specifications when
installing fasteners in order to avoid damage to parts and systems.
- Turn the over-center
adjusting screw counterclockwise until the torque wrench shows a reading of
0.7-1.1 N·m (6-10 lb in)
higher than the previous reading. The total reading must not exceed 3 N·m
(27 lb in).
Tighten
Tighten the adjustment lock nut (1) to 89 N·m (66 lb in).
- Check the adjustment. Adjust again if necessary.
- Connect the hydraulic hoses following the tag locations.
Tighten
Tighten the high pressure connections to 38 N·m (28 lb ft).
- Connect the cardan clamp.
- Install the cardan clamp bolt. Adjust the cardan clamp. Refer
to Steering Wheel and Column.
- Connect the pitman arm. Refer to
Pitman Arm Replacement
in Steering Linkage.
Steering Gear Pitman Shaft Over-Center Preload Adjustment - Off Vehicle Saginaw - 708 Model
Steering Gear Adjustments
Important: Any steering gear adjustment is made only as a correction and not as
a periodic adjustment.
Remove the gear from the vehicle prior to any adjustments.
- Drain the power steering fluid from the gear.
- Mount the gear in a vise.
Important:
• | Adjust the worm thrust bearing preload first, then adjust the
pitman shaft over-center preload. |
• | The worm thrust bearing preload is controlled by the amount of
compression force exerted by the adjuster nut assembly on the flat races. |
• | The pitman shaft over-center preload is controlled by the pitman
shaft adjuster screw, which determines the clearance between the rack piston
and the pitman shaft sector teeth. |
- Adjust the following:
3.1. | The worm thrust bearing preload |
3.2. | The pitman shaft over-center preload adjustment |
Worm Thrust Bearing Preload Adjustment
Tools Required
J 42882 Adjuster
Nut Socket
- Rotate the stub shaft (3)
back and forth in order to drain the power steering fluid.
- Remove the coupling shield retainer and the lock nut (2)
from the steering gear housing (1) using a drift and a hammer.
Notice: Use the correct fastener in the correct location. Replacement fasteners
must be the correct part number for that application. Fasteners requiring
replacement or fasteners requiring the use of thread locking compound or sealant
are identified in the service procedure. Do not use paints, lubricants, or
corrosion inhibitors on fasteners or fastener joint surfaces unless specified.
These coatings affect fastener torque and joint clamping force and may damage
the fastener. Use the correct tightening sequence and specifications when
installing fasteners in order to avoid damage to parts and systems.
- Turn the adjuster
nut assembly (1) clockwise using J 42882
until the adjuster nut assembly (1) and the thrust support
assembly (2) are firmly bottomed in the steering gear housing (3).
Tighten
Tighten the adjuster nut assembly (1) to 28-31 N·m
(20-23 lb ft).
- Place an index mark (1)
on the steering gear housing (4) parallel with one of the holes (3)
in the adjuster nut assembly (2).
- Measure back counterclockwise
13 mm (½ inch).
- Place a second mark (2) on the steering gear housing (1).
- Using J 42882
and a torque wrench, turn the adjuster
nut assembly (1) counterclockwise 15-25 degrees in order to align
the hole (2) in the adjuster nut assembly (1) with the second
mark (4) on the steering gear housing (3).
- Install the coupling shield
retainer and the lock nut (2).
- Hold the adjuster nut assembly in position in order to maintain
alignment of the marks.
- Tighten the coupling shield retainer and the lock nut (2)
using a drift in a notch.
Pitman Shaft Over-Center Preload Adjustment
- Rotate the stub shaft (3)
back and forth in order to drain the power steering fluid.
- Loosen the adjuster lock nut (4).
- Turn the pitman shaft adjuster screw (1) counterclockwise
until the screw is fully extended.
- Turn the pitman shaft adjuster screw (1) clockwise 1 full
turn.
- Rotate the stub shaft (3) from stop to stop, using a 12-point
socket while counting the number of turns.
- Starting at either stop, turn the stub shaft (3) back half
of the total number of turns. This is the center of the gear.
- Ensure that the gear is
centered by verifying the following items:
• | The flat on the stub shaft (3) faces upward. |
• | The flat on the stub shaft (3) is parallel with the side
cover (2). |
- Align the master spline (5) on the pitman shaft (4)
with the adjuster screw (1).
- Place a torque wrench
on the stub shaft (2) with the handle in the vertical position.
- Rotate the stub shaft (2) 45 degrees from each side
of the center of the stub shaft. The stub shaft (2) must rotate smoothly.
- Record the worm bearing preload measured on or near the center (1).
The recorded bearing preload must be 0.7-1.7 N·m (6-15 lb in)
with the worm and the ballnut installed. If the torque is outside of this
range, readjust or repair the steering gear assembly as required.
- In order to obtain the correct preload torque, adjust the over-center
torque by turning the pitman shaft adjuster screw clockwise.
- Add 0.7-1.1 N·m (6-10 lb in)
torque to the previously measured worm bearing preload torque.
Tighten
Tighten the adjuster lock nut to 49 N·m (36 lb ft).
Prevent the adjuster screw from turning while tightening the adjuster lock
nut.