Steering/Alignment - Vehicle Drift/Pull
Article No. 85-13-12STEERING - DRIFT/PULL
LIGHT TRUCK 1980-85 F100/150 (4x2), 1983-85 RANGER (4x2)
A side-to-side caster difference can contribute to a vehicle drift in the direction of the side with less caster. If the difference cannot be corrected by Shop Manual procedures (greater than 3/4~ difference), a service kit (for use on vehicles with forged axles) can be used to increase front wheel caster angle on either or both wheels to balance the caster split. The kit contains complete parts and instructions needed to modify the front radius arm and mount a metal cam on the bottom of the arm. The kit can increase caster from 1/2~ to 3 degrees, in 1/2~ increments. It is not designed to decrease caster. Vehicles with stamped axles cannot utilize the caster kit, but can be serviced with a different procedure.
To increase front wheel caster angle of subject vehicles with forged front axles to balance the caster split, the following procedure is suggested:
1. Remove radius arm from the vehicle as shown in Section 14-21 of the Shop Manual and choose appropriate paper template contained in the service kit and identified by vehicle model.
Figure 7 - Radius Arm:
Figure 8 - Radius Arm:
2. Locate the template on the bottom flange of the radius arm. Figures 7 and 8 show a typical arm modification for the F150 4x2 right hand arm. One template per vehicle model is used to modify both the right and left hand arms. When modifying the right hand arm, position the template with the printed side downward. The F Series template locates off of one of two existing holes in the arm. The Ranger template is shaped to match the contour of the edges of the arm.
3. With template secure, make a punch mark at the center of the small hole inside the printed circle. Scribe the slot printed/cut-out on the template and die-grind out the slot at the axle-attaching hole the same size as the slot in the template and de-burr the surface avoiding rounding the edges of the slot.
4. Drill a 0.228 inch diameter hole at the punch mark. Use this hole to mount the cam with the 1/4-20 self-tapping screw supplied.
Figure 9:
5. Figure 9 shows a typical cam installation. Each hole in the cam represents a 1/2 degree caster increase. A caster increase of approximately 2 degrees for F-150 4x2 for example will be obtained by mounting the cam with the self-tapping screw in
the No. 2 hole of the cam to the lower flange of the radius arm.
Figure 10:
6. Figure 10 shows a typical F-100/150 4x2 vehicle installation. TORQUE BOLT A AND NUT B TO:
160 to 220 ft.lbs. Ranger 4x2
270 to 330 ft.lbs. F Series
7. Reset front wheel toe to zero after installation is complete.
The following are methods for adjusting caster on vehicles with stamped front axles:
1. TSB No. 82-10-18 provides a 1/2 degree adjustment per side to correct a caster split of 1 degree.
2. For caster splits greater than 1 degree the axleattaching hole in the radius arm can be slotted to allow more axle rotation for increasing caster. SLOT ONLY ONE HOLE IN THE UPPER EAR OF THE RADIUS ARM (AT THE SPRING SEAT). DO NOT SLOT THE LOWER EAR OF ANY RADIUS ARM WITH STAMPED AXLES. Slotting the upper hole rearward 1/8 inch will provide approximately 1 degree of caster increase. With the slotted radius arm and axle loosely assembled, twist the axle (top of axle rearward) while torquing the axle-to-radius arm joint before the spring seat is installed. Verify correct torque with a torque wrench - do not depend on an impact wrench for final torque.
AXLE/RADIUS ARM TORQUE MODEL
160 to 220 ft.lbs. Ranger 4x2
270 to 330 ft.lbs. F Series 4x2
PART NUMBER PART NAME CLASS
E4TZ-3KO64-A Kit - Caster Cam R
OTHER APPLICABLE ARTICLES: NONE
WARRANTY STATUS: Reimbursable with in the provisions of the Warranty and Policy Manual. TIME
OPERATION Forged Axle Stamped Axle
3001 A7L Left 1.7 Hrs. 1.4 Hrs.
3001 A7R Right 1.7 Hrs. 1.4 Hrs.
3001 A7T Both 3.1 Hrs. 2.4 Hrs.
DLR. CODING: Basic Part No. 3A360 - Code: 36