Vehicle Lean

Verify side-to-side vehicle lean by measuring the fender lip-to-ground dimension before beginning diagnosis and service actions. Normal acceptable limits are:
^ maximum of 16 mm (5/8-inch) variance between left and right front wheel lips to ground.
^ maximum of 19 mm (3/4-inch) variance between left and right rear wheel lips to ground.

NOTE: Codes identifying the front and rear spring options and springs are printed on the Safety Compliance Certification Label. Replace springs in pairs if one is found to be damaged or worn. If a spring requires replacement because it is damaged or worn, replace only with the same part specified on the label. In rare instances, the spring codes will not reflect the springs installed, due to a DSO option or assembly plant substitution. If a DSO option number is shown on the certification label, the District Office can establish whether springs are affected. If the factory-installed springs do not agree with the code printed on the Safety Compliance Certification Label (right and left coil or leaf spring part numbers should match), replace the damaged or worn spring with a new spring of the same part number as the damaged or worn spring. It will not be necessary to replace the matching, non-worn or undamaged spring.

1. Place the vehicle on a flat, smooth surface.
2. Inspect vehicle for any heavy add-one that can cause excessive weight on any corner of the vehicle.
^ In cases where the excess weight is from a snowplow, a rear tailgate lift, etc., the vehicle must be diagnosed with the equipment in place.
^ Measure corner weights if necessary.
^ Vehicle fuel tank must be full and the vehicle empty of cargo such as tools, equipment or debris.
^ Vehicle must be sitting on the wheels and tires, not on a hoist, jack or jack stands.

3. Check all wheels and tires:
^ Wheels must be same size and design, right and left side, on each axle.
^ Wheel size and design, tire size and tire design should be as indicated on the Vehicle Certification Label.
^ Check air pressure of all tires; inflate to specifications indicated on the Safety Compliance Certification Label.

4. Check front and rear suspension. Make sure the same spring is on the left/right front and left/right rear. The front springs have ID tags indicating the part number. The rear springs have the part number stamped on the bottom just behind the U-bolt attachment.
5. Jounce the vehicle's front and rear suspension to normalize the vehicle static ride height.
6. Measure the height at the right and left fender lip openings.
(1) Measure the front.
(2) Measure the rear.

7. Calculate the side-to-side difference for each dimension. If the difference is greater than 16 mm (5/8 inch) between left and right front or 19 mm (3/4 inch) between left and right rear, corrections can be performed by following the Vehicle Lean Correction procedure. Service and Repair