Alignment - Premature Tire Wear
TS84-087September 17, 1984
Front Axle & Suspension
FRONT SUSPENSION ALIGNMENT, 720 TRUCKS
APPLIED MODEL: 1980 - 1984 720 Trucks
SERVICE INFORMATION
Premature or irregular front tire wear may be caused by excessive toe-out which may be the result of low front suspension height. Prior to setting caster, camber or toe-in on any 720 pickup, ensure that the H-dimensions are within factory specifications.
SERVICE PROCEDURE
1. Before adjusting the H-dimension, exercise the front suspension by bouncing the front of the vehicle 4 or 5 times to ensure that the vehicle is at a neutral height attitude. This should be done on an alignment rack with sliding pads to allow for lateral movement of the wheels. If an alignment rack is not available, roll the vehicle back and forth 3 to 5 feet after exercising the suspension.
2) Determine the H-dimension as follows:
a. Place vehicle on a smooth and level reference surface.
b. Point the front tires straight ahead and ensure that the front tire pressures are equal.
c. Measure distance 'A' between the reference surface and the lower link spindle center. (See Figure 2 or 3 for application). Note the measurement.
d. Measure distance 'B' between the reference surface and the tension rod attaching bolt (Figure 2) or the steering stopper bracket (Figure 3). Note the measurement.
e. Subtract 'B' measurement from 'A' measurement to obtain H-dimension (A - B = H).
f. Ensure that H-dimension measurement is within the H-dimension specifications below.
H-dimension Specifications mm (in.)
MODEL YEAR 2WD 4WD
1980 - 1983 124-129 (4.88-5.08) 134-139 (5.28-5.47)
1983.5 - 1984
Regular Cab 118-122 (4.65-4.80) 44-48 (1.73-1.89)
King Cab 113-117 (4.45-4.61) 39-43 (1.54-1.69)
g. If necessary, turn the adjusting anchor arm bolt to obtain proper H-dimension (See Figure 4).
CAUTION: Do not use an impact wrench on the adjusting anchor arm bolt.
h. Repeat Steps C through H for the opposite front wheel.
i. Exercise the front suspension as described in Step 1.
j. Recheck H-dimension to ensure it is within factory specifications.
3) Refer to the MA section of the Service Manual and check caster, camber and toe-in. Adjust each setting as required with toe-in adjustment as the last operation.
WARRANTY INFORMATION
CS PNC CT 0P CODE FLAT RATE
2V 48510 34 WK12HA 0.8/hr. (Alignment)
WK99AA 0.3/hr. (H-dimension)
1.1/hr. (TOTAL)