Bulletin No.: PIT6154A
Published date: 05/23/2024

Preliminary Information
PIT6154A Diagnostic Tip For Steering Wheel Oscillation Wobble
Shimmy Dither Vibration
Models
Brand:

Model:

Model Years:

VIN:
from

to

Engine:

Transmissions:

Chevrolet

Silverado 3500 HD

2024

All

All

All

All

GMC

Sierra 3500 HD

2024

All

All

All

All

Involved Region or Country North America
Additional Options (RPO)
Condition

Cause

With RPO DZW - DUAL REAR WHEEL
Some customers may comment on a vibration or that the steering wheel has an
oscillation, wobble, shimmy and/or dither. These concerns typically happen at
speeds higher that 40 mph and sometimes are aggravated after hitting a bump.
The cause of this condition could be excessive runout within the front hub
extensions (1), shown below.

Correction:
Important Please Read: On trucks with RPO NV8, if they develop an imbalance/vibration (example tires out of
balance) the power steering control module (PSCM) has a feature that will learn and help remove some of the
imbalance/vibration felt in the steering wheel. The PSCM can only provide a certain amount of correction and
when the issue causing the imbalance/vibration gets bad enough then the driver will start to feel the concern in
the steering wheel. The PSCM learns this mitigation behavior over time (several hundred miles) and after any
repair is made to x an imbalance/vibration and before a road test, the feature MUST BE reset. If it is not reset
after a repair, then during a road test the PSCM will still be trying to mitigate the imbalance/vibration that it
had previously learned, but now is no longer present. Eventually, the PSCM will learn the issue is no longer
present, but it can take a few hundred miles to relearn. To reset this feature, use GDS2 to reset the Active
Pull/Drift Compensation Learn by going into the K43 Power Steering Control Module > Con guration and Reset
Functions > Power Steering Pressure Sensor Learn > Power Steering Active Pull/Drift Compensation Learn and
press the Execute Control Sequence.
If after following normal SI diagnostics and a root cause has not been found, then inspect the front hub
extensions for excessive runout. Remove the wheel and tire assemblies and then use a dial indicator to measure
the face of the hub extension where the wheel mounts. Slowly rotate the hub extension while measuring the
runout, it should not exceed .005" (.127 mm). If the hub extension has excessive runout, then removed it and use
the dial indicator to measure the runout on the face of the brake rotor where the hub extension mounts, again it
should not exceed .005" (.127 mm). If the rotor face is within spec, but the hub extension is out of spec then the
hub extension will need to be replaced. In some cases, the hub extension may not need to be replaced if the
brake rotor face has some runout, but within spec. It may be possible to index the low spot on the rotor face with
the high spot on the hub extension, then remeasure the hub extension runout to see if it is now within spec. On
trucks with RPO NV8, please read the important statement above before going on a test drive.

NOTE: After installing a new front hub extension, recheck the runout to verify it does not exceed .005" (.127 mm).
Remember: SI vibration diagnostics are found under General Information > Vibration Diagnosis and Correction >
Diagnostic Information and Procedures
Additional Diagnostic Tips
1. Wheel/Tire balancing can also be a contributing factor. The wheel/tire assemblies on HD trucks can be di cult
to properly mount/center on the Hunter 9700 wheel balancer if the proper adapter is not used. Please reference
the latest version of 10-03-10-001 for the proper wheel adapters. It is recommended to get the road force values
to less than 30 lbs for the FRONT tires.
2. When reinstalling the front wheel/tire assemblies onto the vehicle, it is important to get them centered on
the hub extension. These trucks do not use tapered lug nuts and when the wheel/tire assembly is installed on the
vehicle, if there is any play in the center pilot hole the weight of the assembly will cause the wheel not to be
centered on the hub extension. After placing the front wheel/tire assembly on the hub, temporarily install 2 to 4
tapered lug nuts that are equally spaced around the wheel studs and lightly snug them up, shown below (2). The
tapered lug nuts will help center the wheel/tire assembly onto the hub extension. Then reinstall the proper
factory lug nuts in the other open stud locations and tighten down equally. Once the proper lug nuts are
tightened down now REMOVE the tapered lug nuts, reinstall the remaining factory lug nuts in their place and
torque all lug nuts down equally to speci cation.
3. On trucks with RPO NV8, after making any repair to x an imbalance/vibration please read the important
statement above before going on a test drive.

Warranty Information
For vehicles repaired under the Bumper-to-Bumper coverage (Canada Base Warranty coverage), use the following
labor operation. Reference the Applicable Warranties section of Investigate Vehicle History (IVH) for coverage
information.
Labor Operation
8030530

Description
Front Wheel Hub Extension Replacement

Version History
Version
Modi ed

2
04/24/2024 - Created on.
05/23/2024 - Updates to the correction section.

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Labor Time
Use Published Labor time