Runout compensation separates the true wheel direction from small mounting and wheel variations. Without compensation, the aligner may interpret a tilted clamp, imperfect rim or mounting offset as part of the vehicle alignment.
Compensation is required after targets are installed.
The target-to-wheel relationship must not change afterward.
Rolling and raised methods solve the same geometric problem through different workflows.
Repeat compensation whenever a clamp or target is disturbed.
Why compensation is necessary
A target attached to a wheel rarely sits in a mathematically perfect plane. Rim runout, clamp contact points, tire-clamp seating and target mounting can create a small angular offset. The aligner observes the target at multiple wheel positions and calculates the center of rotation, allowing it to remove that mounting offset from the alignment measurement.
Compensation does not repair a bent wheel. It prevents the target mounting condition from being mistaken for toe or camber. A wheel that is unsafe or badly damaged still requires service.
Rolling compensation
During rolling compensation, the vehicle moves a controlled distance so each wheel rotates while remaining loaded. Imaging cameras track the targets through the movement. This method is efficient because all wheels can be compensated together, but it depends on a clear path, correct plate state and controlled movement without steering.
- Position the vehicle as instructed and keep the steering straight.
- Install clamps and targets securely.
- Unlock the required plates or follow the system prompt.
- Roll smoothly through the requested distance.
- Stop at the indicated position without braking or steering sharply.
- Confirm all wheels completed compensation.
Raised compensation
Raised compensation rotates each wheel while the vehicle or axle is lifted according to the procedure. It can be useful when the bay does not allow rolling or when a specific service workflow requires it. The suspension must be returned to the correct measurement position and settled after the vehicle is lowered.
| Method | Strength | Main control point |
|---|---|---|
| Rolling | Fast, loaded, all wheels together | Straight controlled vehicle movement. |
| Raised | Works with limited rolling space | Correct lift points and suspension settling. |
| Split or directional variants | Adapt to bay and vehicle limits | Follow software sequence exactly. |
| Rapid roll | Short efficient movement where supported | Camera visibility and precise stopping. |
Protecting the compensation relationship
Once compensation is complete, the target and clamp become a calibrated assembly relative to that wheel. Do not remove, rotate, strike or reposition them. If a clamp slips, a target is folded or a wheel is removed, repeat compensation for the affected wheel or the complete vehicle as required by the software.
Quality checks
- Clean clamp contact points and verify correct fit.
- Use the correct clamp range for the tire or wheel.
- Keep targets within the camera field of view.
- Do not roll over plate edges or stops.
- Avoid steering input during the movement.
- Confirm the final vehicle position leaves plates free.
- Repeat any wheel that shows an incomplete or inconsistent result.
After compensation
Settle the suspension, release any brakes applied during movement and confirm the steering remains centered. Proceed to the caster sweep and other measurements. If readings are unexpectedly different after compensation, check vehicle position, plate freedom and clamp security before making adjustments.
Frequently asked questions
Can compensation be skipped with precision wheel clamps?
No. Even high-quality clamps and wheels have mounting variation. Compensation is part of the measurement process.
Must all four wheels be compensated?
For a four-wheel measurement, yes, unless the aligner and service procedure explicitly support another method.
Why repeat compensation after removing a wheel?
The target will not return to exactly the same angular relationship when reinstalled, so the previous correction is no longer valid.
Technical content reviewed for TreadPlus Learn v1.0 · Updated July 16, 2026