Nose Landing Gear: Shimmy Vs. Out-Of-Balance Wheel

December 2025

Over the course of normal operation, an operator of any aircraft with torque link bushings on the nose landing gear to experience a shimmy in the nose gear. However, our experience and expertise indicate that operators can sometimes confuse an out-of-balance nose wheel with a shimmy. They are two separate issues, and a few more probing questions are necessary to get to the heart of the matter.

Nose Wheel Shimmy

A symptom of a shimmy is the rapid, uncontrolled, side-to-side oscillation of the nose wheel, moving left to right, causing a shudder that can sometimes be felt through the flight controls, such as the rudder pedals.

This condition can be isolated by verifying the play at the upper and lower scissors.

• If play is noted, contact Duncan Aviation’s Accessory Overhaul Servicesfor bushing replacement.
• If there is no play in the upper and lower scissors, other causes could include steering rack wear, feedback linkage, or the lower barrel bearing.

Out of Balance Nose Wheel

If the crew notices a vertical oscillation through the nose wheel well, sometimes evident after takeoff, the nose wheel may be out of balance.

• Remove and balance.
• Perform a visual inspection of the nose wheel bearings and ensure the nose wheels are installed using the appropriate maintenance manual torque value.