Diagnostic Procedure #3 - Steering Gear Mesh Load

Article No.
94-20-13

10/15/94

DIAGNOSTIC PROCEDURE # 3 - STEERING GEAR MESH LOAD

MESH LOAD CHECK/RESET

If the steering system exhibits on-center free play, or in general displays a vague on-center feel or lash, this could contribute to reduced straight-line stability and a customer perception of drift or pull. In these cases, a fall-off in factory-set levels of steering gear mesh load may be the cause. If a mesh load reset is required, follow the procedure closely. Setting mesh load too high may result in customer dissatisfaction with higher efforts and overall steering feel.

ADJUSTMENT IN VEHICLE

Adjust total on-center load to eliminate excessive lash between the sector and rack teeth as follows. See mesh load specification below for checking and setting values. This is the only adjustment required.

1. Disconnect the steering gear sector shaft arm from the steering gear sector shaft using Pitman Arm Puller T64P-3590-F.

2. Disconnect the power steering return hose at the power steering oil reservoir and cap the reservoir return line pipe.

3. Place the end of the power steering return hose in a clean container and turn the steering wheel from stop-to-stop several times to discharge the fluid from the steering gear. Discard the fluid.

4. Turn the steering wheel 45 degrees from the right stop.

5. Attach an inch-pound torque wrench to the steering wheel nut. Determine the torque required to slowly rotate the shaft from the 45 degree position back toward center (approximately 1/8 turn).

6. Turn the steering gear back to center and determine the torque required to rotate the steering gear sector shaft back and forth across the center position (+/- 90 degrees). Refer to the following chart for checking and resetting specifications. If reset is required:

a. Loosen the adjuster locknut and turn the sector shaft adjuster screw until the reading is the specified value greater than the torque at 45 degrees from the stop.

b. Hold the sector shaft screw in place and tighten the locknut.

MESH LOAD CHECKING AND SETTING

1. Checking

^ Reset if mesh load measured while rocking power steering gear input shaft and control over center is less than 7 lb.in. (.8 N-m) greater than the torque 45 degrees from the right stop (e.g., about 13 lb.in. (1.5 N-m) total on center load).

2. Reset

^ Set torque measured rocking across center to a value 10-15 lb.in. (1.13-1.7 N-m) greater than that measured 45 degrees from the right stop. This should be an approximate 15-20 lb.in. (1.7-2.3 N-m) of total on-center load.