Steering - Pulls Left When Braking
Article No.92-18-10
08/26/92
STEERING - LEFT DRIFT OR PULL DURING BRAKING - "RECESSION STEER" - F-SERIES 4X2 LIGHT DUTY AND F-150/BRONCO 4X4
LIGHT TRUCK:
1980-92 BRONCO, F-150
1989-92 F-250
ISSUE:
The vehicle may drift or pull left during braking, with no torque in the steering wheel. This condition is known as "recession steer" and may be caused by the radius arm front pivot bushings.
ACTION:
Confirm that "recession steer" exists and, if necessary, replace the left hand radius arm bushing with the flat front retainer and both front pivot bushings. Refer to the following procedure for service details.
NOTE:
THIS PROCEDURE CAN ONLY BE USED IN CONJUNCTION WITH TSB 91-21-8 TO COMPLETELY RESOLVE THIS CONDITION.
IDENTIFY CONCERN
Confirm that "recession steer" exists and segregate it from possible brake pull.
^ "Recession steer" must be correctly identified and segregated from brake pull. "Recession steer" is identified by the vehicle drifting or pulling left during braking with no torque felt in the steering wheel.
^ With the right hand radius arm pivot bracket bolted on, as in current production, and no brake imbalance (correctly performing TSB 91-21-8 will assure this), the amount of left drift that could result from "recession steer", if corrective steering wheel input is not applied, during a moderate hard stop from 50 mph (80 km /h), is no more than 4 feet (1.2 m). The revised bushings are designed to correct this magnitude of "recession steer".
REMOVAL AND REPLACEMENT
Refer to the to the 1992 F-Series And Bronco Service Manual, Section 04-01A, for removal and replacement of the following components.
1. Replace the left hand (driver's side) radius arm bushing cupped front retainer with the flat front retainer (F2TZ-3B186-A).
2. Replace the left hand (driver's side) radius arm front pivot bushing with the new bushing (F2TZ-3B203-A). It is yellow in color with "LEFT HAND ONLY" molded in the front face.
3. Replace the right hand (passenger side) radius arm front pivot bushing with a new bushing (F2TZ-3B203-B).
NOTE:
REUSE THE ORIGINAL NYLON REAR BUSHING SPACER AND REAR BUSHING, UNLESS EXCESSIVE WEAR IS FOUND. REPLACE WITH (E5TZ-3B244-A) AND (D9TZ-3B203-A) RESPECTIVELY, IF REPLACEMENT IS NECESSARY. TIGHTEN BOTH THE LEFT HAND AND RIGHT HAND RADIUS ARM NUTS TO THE SPECIFIED 80-120 LB.FT. (109-163 N-m).
4. Set total toe to 1/32" (.794 mm) toe in.
PART NUMBER
NOTE:
TIMES FOR TSB 91-21-8 DIAGNOSTICS WILL VARY DEPENDING ON WHAT IS FOUND. THEREFORE, DIAGNOSTIC TIME IS NOT INCLUDED. REFER TO TSB 91-21-8 FOR DIAGNOSTIC TIMES.
OPERATION DESCRIPTION