Design Height Measurement
OVERVIEW1. Place the vehicle on a level, flat surface such as an alignment rack or drive-on lift that will allow access to the underside of the vehicle.
2. Check that all tires are at the specified inflation pressure. Adjust the pressure as necessary.
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.
3. Loosen the mounting bolts for the following suspension components. 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.
- Front and rear lower control arm to frame bracket mounting bolts.
- Front and rear upper control arm to frame bracket mounting bolts.
- Front upper control arm to pivot bar mounting bolts.
- Front and rear shock assembly to frame bracket mounting bolts.
- Front and rear shock assembly to lower control arm mounting bolts.
If the vehicle is equipped with the BBS racing wheels (ACR package), proceed with the following BBS Wheel Height Gage Adapter Installation (ACR) first. Otherwise, proceed directly to the Measurement Procedure.
BBS WHEEL HEIGHT GAGE ADAPTER INSTALLATION (ACR)
1. Place an Adapter, Special Tool 8396-1, inside the larger end of each Suspension Height Gage, Special Tool 6914, aligning the adapter thumb screw with the notch in the Fixture. The beveled edges on both tools should be on the same side as shown.
2. Tighten the thumb screws.
3. Place an Adapter, Special Tool 8396-2, over the smaller end of each Suspension Height Gage, Special Tool 6914, aligning the adapter locating pin with the notch in the Fixture. The beveled edges on both tools should be on the same side as shown.
4. Tighten the thumb screws.
MEASUREMENT PROCEDURE
NOTE: When the suspension height gages are installed on the wheels, they must be positioned at the very bottom of the wheel rim. This is required to ensure the height checking fixtures are parallel to the bottom surface of the frame rails, which is required to achieve an accurate vehicle design height measurement.
NOTE: When the height checking fixtures are installed on the wheels, they must be positioned at the very bottom of the wheel rim. This is required to ensure the height checking fixtures are parallel to the bottom surface of the frame rails, which is required to achieve an accurate vehicle design height measurement.
1. Install front and rear Suspension Height Gages, Special Tool 6914, on the vehicle. Ensure that the gages are correctly attached to the inner rim flange at the very base of the wheels. Refer to step a. below for standard wheels or to step Step b. below for BBS racing wheels (ACR package).
a. For standard wheels, engage the notch in each end of the height gages on the wheels flanges as shown in the figure.
b. For BBS racing wheels, install the adapters placed attached to each end of the height gages against the very base of wheels as shown in the figures.
NOTE: Note: When lowering the vehicle to its specified design height, do not add all the ballast (weight) to the trunk and passenger compartment at one time. Add the ballast to the vehicle slowly until the correct distance between the Suspension Height Gage and the frame of the vehicle is achieved.
NOTE: The approximate total weight needed to lower the vehicle to its design height is 400 pounds depending on the suspension type. The weight distribution in the vehicle is approximately 330 in the passenger compartment (165 pounds per seat) and 70 pounds in the luggage compartment. If the spare tire is not in the trunk, approximately 40 additional pounds will need to be placed in the trunk to compensate for the tire. Vehicles equipped with the ACR suspension package will require additional weight in all listed places.
2. Add ballast weight as required to the passenger compartment of the vehicle to lower the front of the vehicle to the specified design height.
CAUTION: Do not over-ballast the vehicle. If vehicle is over-ballasted, the design height will be incorrect and the special tool can be bent.
3. Measure the vehicle's front design height by measuring the distance between the top of the Suspension Height Gage and the frame rails.
4. Add ballast weight as required to the trunk of the vehicle to lower the rear of the vehicle to the specified design height.
5. Measure the vehicle's rear design height by measuring the distance between the top of the Suspension Height Gage and the frame rails.
6. After ballasting the rear of the vehicle, recheck the front design height to see if the front of the vehicle lifted when rear was ballasted. If necessary, add weight to the passenger compartment of the vehicle, lowering the front of the vehicle back down to the required design height. Keep checking front and rear of vehicle until no further adjustment is required and the vehicle is at the correct front and rear design height.
7. Tighten the mounting bolts for the following suspension components to the specified torque values.
- Front and rear lower control arm to frame bracket cam adjustment bolts and nuts to 101 Nm (75 ft. lbs.).
- Rear upper control arm to frame bracket pivot bolts 95 Nm (70 ft. lbs.).
- Front upper control arm to pivot bar mounting end nuts 136 Nm (100 ft. lbs.).
- Front and rear shock absorber to frame bracket mounting bolts 136 Nm (100 ft. lbs.).
- Front shock absorber to lower control arm mounting bolts 136 Nm (100 ft. lbs.).
- Rear shock absorber to lower control arm mounting bolts 190 Nm (140 ft. lbs.).
8. Remove the ballast from the trunk and passenger compartment of the vehicle.
NOTE: When jouncing the vehicle, the vehicle must be released at the bottom of the jounce cycle. This will ensure the vehicle's suspension will raise the vehicle to the correct curb height at the top of the jounce cycle.
9. Lightly jounce the front and rear suspension of the vehicle to ensure vehicle is settled at curb height.
10. Measure and record the vehicle's front curb height by measuring the distance between the frame rail and the top surface of the Suspension Height Gage (at front edge).
11. Measure and record the vehicle's rear curb height by measuring the distance between rear frame rails and the top surface of the Suspension Height Gage.
12. Compare the recorded curb height measurements to specifications. Refer to Curb Height And Design Height Specifications.
If the recorded measurements do not match specifications, refer to Curb Height Measurement.
13. Remove the Suspension Height Gages from the vehicle.