Design Height Measurement - ACR
DESIGN HEIGHT MEASUREMENT - ACR
NOTE: This procedure is designed to be performed with original factory wheels and tires installed. Non-OEM wheel or tires may cause inaccurate measurement.
1. Verify vehicle fuel tank is full of fuel. If tank is not full of fuel, reduction in weight will affect height of vehicle and design height measurement.
2. Remove any load within passenger and luggage compartments that is not factory equipment.
3. Place vehicle on wheel alignment rack or drive-on lift per equipment manufacturer's recommendations.
4. Check all tires for proper inflation pressure and adjust as necessary.
CAUTION: Only apply weight to seat cushions as described in 5. Do not over-ballast the vehicle. If vehicle is over-ballasted, the design height will be incorrect.
5. Add 150 pounds ballast weight (2, 3) to each seat cushion (1, 4) of vehicle (300 pounds total) to lower vehicle to specified design height.
6. Place a straightedge from lift runway to runway directly below the wheel center line for both front and rear axles. If a straightedge cannot be located, Height Gages, Special Tool 6914, can be used. Do not attempt to place Height Gages on wheel flanges, only across lift runways as indicated here.
7. Jounce vehicle several times, each time paying special attention to release vehicle at very bottom of jounce cycle. This is very important in allowing suspension to settle to correct height.
8. Measure and record vehicle's front design height. Measure distance (1) straight up from bottom of straightedge (4) to each frame rail at the nearest point to the Principle Locating Point (PLP) hole (2).
9. Measure and record vehicle's rear design height. Measure distance (1) straight up from bottom of straightedge (4) to each frame rail at the nearest point to the Principle Locating Point (PLP) hole (2) (not belly pan).
10. Compare recorded measurements to specifications. Wheel Alignment
11. If recorded height is outside of specifications, jounce vehicle and remeasure. Before remeasuring design height, be sure to jounce the vehicle as described in 7. If still outside specifications, spring height on shock assembly may need to be adjusted or one or more of following rubber bushing mounted suspension components may not be properly positioned and tightened. To adjust spring height, refer to the Owners Manual Addendum for ACR. To adjust rubber bushing mounted suspension components, loosen either front, rear or all components as necessary at the following locations allowing suspension to enter specified design height.
- Front and rear lower control arm to frame bracket cam adjustment bolts.
- Front and rear upper control arm to frame bracket mounting bolts.
- Front and rear shock assembly to frame bracket mounting bolts.
- Front and rear shock assembly to lower control arm mounting bolts.
NOTE: When loosening the lower control arm mounting bolts, be sure the alignment adjustment cams do not turn. The cams must stay in their original position so the alignment of the vehicle is not affected.
NOTE: The mounting bolts must be loosened enough to allow the suspension of the vehicle to move without loading (twisting) the rubber insert of the isolator bushings.
12. Tighten previously loosened mounting bolts to specified torque values. Front Suspension Specifications Rear Suspension Torque Specifications
- Front and rear lower control arm to frame bracket cam adjustment bolts and nuts.
- Front upper control arm to frame bracket mounting bolts.
- Rear upper control arm to frame bracket mounting bolts.
- Front and rear shock assembly to frame bracket mounting bolts.
- Front shock assembly to lower control arm mounting bolts.
- Rear shock assembly to lower control arm mounting bolts.
13. If wheel alignment is to be performed, proceed at this point. Service and Repair
14. Remove ballast weight from vehicle, allowing vehicle to return to curb height.