Steering - Shimmy Diagnostic/Repair Procedure: Overview
Article No.98-15-8
08/03/98
STEERING - SHIMMY - DIAGNOSTIC PROCEDURE -
4X2 AND 4X4 VEHICLES
LIGHT TRUCK:
1988-97 F SUPER DUTY, F-250 HD, F-35O
This TSB article is being republished in its entirety to include the latest level parts and to include the F-250 HD 4X4.
The F-250 and F-350 listed include 4X4 and 4X2.
ISSUE
Front end shimmy may occur at various driving speeds and is usually induced when hitting bumps such as large potholes or rough railroad crossings. Shimmy is not always verified during the road test.
ACTION
Check all the systems that can cause shimmy. After a general review of the front suspension and steering systems, make the necessary adjustments as noted in the following diagnostic procedure. The review should include bolt and nut torques to ensure they are to specified torques. When encountering excessively worn tires, shackle bushings and out-of-balance wheel or tire assemblies, refer to the appropriate Service/Workshop Manual, Section 04-00.
Shimmy, as observed by the driver, is defined as large amplitude, rotational oscillations of the steering wheel resulting from large, side-to-side (lateral) tire/wheel movements. Shimmy should not be confused with nibble, a condition resulting from tire interaction with various road surfaces and observed by the driver as small amplitude, rotational oscillations of the steering wheel. To diagnose nibble and other vibrations which are sometimes confused with shimmy, such as steering column shake or wheel/tire imbalance, consult the Noise/Vibration/Harshness (NVH) diagnostic, Brake NVH and Tire NVH sections in the appropriate Service/Workshop Manuals.
The following items will contribute to the shimmy condition and should be inspected and repaired as required to assure the total repair effectiveness. After all components have been reviewed and repaired, install the appropriate Steering Damper Kit.
Parts Block
OTHER APPLICABLE ARTICLES: 96-20-13, NONE
SUPERSEDES: 97-21-11
WARRANTY STATUS: Eligible Under The Provisions Of Bumper To Bumper Warranty Coverage For 1992-97 Model Years, Basic Warranty Coverage For 1988-91 Model Years
OPERATION DESCRIPTION TIME
981508A Inspect Steering Linkage, 1.2 Hrs.
Frame Ball Joints Or King
Pins (Includes Road Test,
Check Torque
Specifications, Inspect
Steering Linkage Joints
And Gear Box Mounting
Surface)
981508B Replace Tie Rod, Tie Rod 0.5 Hr.
End And/Or Drag Link
Assembly - One (1) Or
Two (2)
981508C Replace Tie Rod, Tie Rod 0.6 Hr.
End And/Or Drag Link
Assembly - Three (3) Or
More
981508D Inspect Wheel Bearing End 0.2 Hr.
Play And Presence Of
Steering Gear Meshload
981508ET Adjust Both Front Wheel 0.9 Hr.
Bearings
981508F Adjust Steering Gear Only 0.6 Hr.
- In Chassis
981508G Replace Steering Gear 1.7 Hrs.
Sector Shaft
981508H Check Front Tire Balance 0.4 Hr.
981508I Check Tire Size And 1.1 Hr.
Pressure, Measure
Alignment Settings
981508J Reset Alignment To 0.6 Hr.
Specifications
981508K Install Steering Damper Kit 1.2 Hrs.
(Includes Road Test For
Verification)
DEALER CODING
CONDITION
BASIC PART NO. CODE
3E651 38
OASIS CODES: 303000, 304000, 306000, 703000, 703200, 703300