2021-2026 Jeep Wrangler Front End Shimmy TSB S1819000004

Owners of 2021-2026 Jeep Wrangler vehicles may experience a condition described as a "Shimmy Felt In Front End," particularly after encountering road irregularities such as expansion joints, potholes, or bumps. Manufacturer Communication S1819000004 Rev. R, released in December 2025, provides detailed diagnostic and repair guidance for technicians to address this Jeep Wrangler front end shimmy concern.

This bulletin emphasizes that a thorough inspection is crucial to identify the underlying cause of the Jeep Wrangler front end shimmy rather than simply replacing components without proper diagnosis. It outlines specific steps to diagnose and resolve the issue, ensuring the root cause is addressed.

Symptoms

The primary symptom reported by owners is a "Shimmy Felt In Front End" which manifests as a vibration or oscillation in the steering wheel. This condition is typically noticed after the vehicle encounters an irregularity in the road surface.

Important Warnings

Technicians are advised that the information in this document is supplementary to official service information and diagnostic procedures, and service information related to this issue is currently being updated. Crucially, the bulletin states:

"The steering damper is not a cause of shimmy, but it is a mitigation device when a vehicle exhibits a shimmy. If a vehicle exhibits shimmy, diagnosis must be performed to identify the root cause of the shimmy."

This means that while a steering damper might reduce the feeling of a shimmy, it does not resolve the underlying problem causing the Jeep Wrangler front end shimmy.

Diagnosis and Repair Procedure Summary

Manufacturer Communication S1819000004 Rev. R outlines a multi-step process for diagnosing and repairing the front end shimmy:

1. Visual Inspection: Technicians should perform a visual inspection of the vehicle to identify any non-factory or aftermarket items that could affect handling. This includes, but is not limited to, suspension lifts (coils, link arms, lift spacers, shock absorbers, drop brackets), oversized tires and wheels, and modified steering components.
2. Tire Inspection and Balancing: Correct tire pressures are critical. Technicians must ensure tires are inflated to the proper specification, especially considering temperature changes from warm to cold weather. Tires should be inspected for wear or damage and replaced if necessary. A road force balance must be performed, with the lowest R1H value tires placed on the front axle.
3. Steering and Suspension Component Inspection: Following the service information for "19 - Steering / Diagnosis and Testing," technicians must thoroughly inspect all steering and suspension joints and components for any signs of wear, looseness, damage, or failure. Any identified issues should be corrected. If necessary, a wheel alignment should be performed as part of the repair. After these steps, a test drive is required to verify if the shimmy condition is still present. If the condition persists, the technician should proceed to the next step; if not, the vehicle can be returned to the owner.
4. Steering Damper Inspection and Action: The next step involves inspecting the part number of the currently installed steering damper. The technician must determine if the current damper's part number matches the latest replacement part available in the Star Parts catalog.
   • If the current damper matches the latest Mopar service replacement part, it should not be replaced. Instead, the technician should follow service information for purging the damper (specifically, "19-Steering, Damper, Remove and Replace"). This purging process involves rotating the steering wheel five full lock-to-lock turns to remove any trapped air. A subsequent test drive is then performed.
   • If the current damper does not match the latest revision part, it must be replaced with the updated part. Technicians should refer to the Star Parts Catalog for the latest part information and consult the Diagnostic Videos section in the Service Library or Service Info Group 19 for steering damper installation instructions. It is crucial that "Orientation instructions must be followed with bump down" during installation.

Owner Action

If you are experiencing a front end shimmy in your 2021-2026 Jeep Wrangler, it is recommended to have your vehicle inspected by a qualified technician. They will follow the diagnostic steps outlined in Manufacturer Communication S1819000004 Rev. R to identify and correct the root cause of the issue.

NHTSA Source: S1819000004 Rev. R