2021 Western Star 49X - Vibration in Steering at 65 MPH

Question

Brand new 49X and I'm fighting a steering wheel shake that starts exactly at 62 mph and goes away at 70. I can see the passenger seat shaking too. It's driving me crazy on long hauls.

I've had the steer tires balanced twice and even did a 3-axle alignment. The shop says everything is tight in the front end—kingpins, tie rods, and drag link are all solid. What else could it be on a truck with only 80k miles?

FordGuyFrank · Accepted Answer

✅ Confirmed fix: Found that the steer tires were 'out of round' (radial runout). Even though they were balanced, they weren't perfectly circular. Replaced the tires with a different brand and the shimmy disappeared completely.

ShopForemanShane · Answer

Check your ride height. If the rear air bags are set too high or too low, it changes the driveline angle and can cause a harmonic vibration that feels like it's coming from the front but is actually the driveshaft.

2021 Western Star 49X - Vibration in Steering at 65 MPH

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