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Vehicle Lean Check - F-150-250-350 (4x2), F-150 (4x4) and Bronco
IF THE IMAGE IS TOO SMALL, click it.

All vehicles are expected to exhibit a slight lean caused by differences in-side-to-side weight distribution generated by various option content. The flow chart has been developed to help diagnose lean concerns due to possible suspensions involvement.

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

Once a lean condition has been verified, the following procedure should be followed to resolve the condition:

1. Place the vehicle on a flat, smooth surface. Vehicle should be inspected for any heavy add-ons that may cause excessive weight on any corner of the vehicle. In cases where the excess weight is a snow plow, a rear tailgate lift, etc., the vehicle must be diagnosed with the equipment in place. Measure corner weights if unsure. Vehicle should be empty, fuel tanks should be full, no cargo in the pick-up box or rear body section of Bronco, such as tools, equipment or debris. Vehicle must be sitting on the wheels and tires and not a hoist, jack or jack stands.

2. 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 Vehicle Certification Label.


3. Check front and rear suspension. Make sure the same spring is on the left/right front and left/right rear. The front springs have I.D. tags indicating the part number. The rear springs have the part number stamped on the bottom just behind the U-bolt attachment.

4. Jounce the vehicle's front and rear suspension to normalize the vehicle static ride height.

5. Measure the height of the right and left fender lip openings for both front (dimension A) and rear (dimension B). Calculate the side-to-side differences for each dimension. If these differences are greater than 16mm (5/8 inch) between left or right front and/or 19mm (3/4 inch) between left and right rear, adjustment can be performed following the procedure under Adjustments in this section.

Vehicle Lean Correction:

Side Lean

A side-to-side lean at the rear of the vehicle can be adjusted by approximately 9.52mm (3/8 inch) by installing a shim between the rear spring and axle on the low side of the vehicle. A "low at the rear" vehicle can be raised approximately 9.52mm (3/8 inch) by installation of one shim on each side. If side-to-side lean at rear is greater than 12.70mm (1/2 inch), switch the rear springs side-to-side. Use the following procedure to install the shim (D7TA-5742-AA):

1. Raise the vehicle frame until the weight is off the rear springs but with the tires still touching the floor.

2. Loosen the spring U-bolts to allow the axle to separate from the spring approximately 12.70mm (1/2 inch).

3. Position the shim (D7TA-5742-AA) between the spring and axle with the long edge of the shim parallel to the side of the spring and the spring tie bolt head through the hole in the shim. On 4x4 vehicles, position the shim between the rear spring and axle spacer. Tape may be used to hold the shim in position.

4. Make sure that the spring leaves are properly aligned and the spring U-bolts contact the edges of the spring assembly or axle seat.

5. Tighten the spring U-bolt sufficiently to be sure that the spring tie bolt head that extends through the shim enters the hole in the axle seat.

Front Lean

Measure the left and right front wheelhouse openings to ground as depicted in the «Vehicle Lean Check» portion of this section. Refer to the «Front Wheel Alignment Specifications» chart for the specified limits on their side-to-side difference or lateral tilt. A vehicle within these limits would not have an objectionable lean appearance. However, if the lean is objectionable, perform the following to adjust:

* Vehicles with coil springs:

If the side-to-side difference is less than 19mm (3/4 inch) install a 6.35mm (1/4 inch) Service Shim (P/N 389117-S2) under the lower spring seat on the low side. No more than one shim is to be added.

If there is a side-to-side difference of 19mm (3/4 inch) or more, remove the high side spring from the vehicle and compare it with a service replacement part having the same part number.

If the free height of the original equipment spring exceeds the free height of the service part by 13mm (1/2 inch), install the service part in this location. If the free height of the original spring is smaller by at least 13mm (1/2 inch), remove the low side spring. Compare the service spring to both of the original sprints and select the two springs most evenly matched. Install the higher spring at the low side.

* Vehicles with front leaf springs:

A service shim (D7TZ-5742-A) is available that installs between the spring and the axle.

For F-Super Duty Commercial and Motorhome Chassis, follow instructions provided with Vehicle Attitude Kit F1DT-5K648-AA.

Rear Lean

A side-to-side lean at the rear of the vehicle can be adjusted by approximately 10mm (3/8 inch) by installing a shim between the rear spring and axle on the low side of the vehicle. A "low at the rear" vehicle can be raised approximately 10mm (3/8 inch) by installation of one shim on each side. Use the following procedure to install the shim (D7TZ-5742-A).

1. Raise the vehicle frame until the weight is off the rear springs but with the tires still touching the floor.

2. Loosen the spring U-bolts to allow the axle to separate from the spring approximately 13mm (1/2 inch).

3. Position the shim (D7TZ-5742-A) between the spring and the spring seat and with the tie bolt head through the hole in the shim. On 4x4 vehicles, position the shim between the rear spring and axle spacer. Tape may be used to hold the shim in position.

4. Make sure that the spring leaves are properly aligned and the spring U-bolts contact the edges of the spring assembly or axle seat.

5. Tighten the spring U-bolt sufficiently to make sure that the spring tie bolt head that extends through the shim enters the hole in the axle seat.

6. Tighten U-bolt nuts to 102-135 N-m (75-100 ft-lb) on F-150 (4x2 and 4x4) Bronco. Tighten to 204-282 N-m (150-210 ft-lb) to F-250-350 (4x2 and 4x4). Tighten to 300-400 N-m (220-300 ft-lb) on F-Super Duty vehicles.
* Tighten to 97-134 N-m (72-98 ft-lb) on E-150. Tighten to 148-202 N-m (109-149 ft-lb) on E-250-350.
* For F-Super Duty Commercial and Motorhome Chassis, follow instructions provided in Rear Spring (Raise) Kit F1DT-5A581-AA.

See also:
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