Wheel Alignment Specifications & Adjustment Procedures: Adjustments Pontiac Bonneville X

Measuring Wheel Alignment

Steering and vibration complaints are not always the result of improper alignment. One possible cause is wheel and tire imbalance. Another possibility is tire lead due to worn or improperly manufactured tires. Lead is the vehicle deviation from a straight path on a level road without pressure on the steering wheel. Refer to RADIAL TIRE LEAD/PULL CORRECTION in order to determine if the vehicle has a tire lead problem.

Before performing any adjustment affecting wheel alignment, perform the following inspections and adjustments in order to ensure correct alignment readings

1. Inspect the tires for the proper inflation. Check for irregular tire wear. Refer to «TIRE DIAGNOSIS - IRREGULAR OR PREMATURE WEAR»(ref-176844-S34795314502005051300000) .
2. Inspect the runout of the wheels and the tires. Refer to «TIRE AND WHEEL RUNOUT SPECIFICATIONS»(ref-177757-S39373591662005060600000) .
3. Inspect the wheel bearings for backlash and excessive play. Refer to «WHEEL BEARINGS DIAGNOSIS»(ref-177943-S04236864432005060800000) .
4. Inspect the ball joints and tie rod ends for looseness or wear.
5. Inspect the control arms and stabilizer shaft for looseness or wear.
6. Inspect the steering gear for looseness at the frame. Refer to «FASTENER TIGHTENING SPECIFICATIONS»(ref-177712-S01971065582005060300000) .
7. Inspect the struts/shock absorbers for wear, leaks, and any noticeable noises. Refer to «STRUTS OR SHOCK ABSORBERS ON-VEHICLE TESTING»(ref-177943-S39896744332005060800000) .
8. Inspect the vehicle trim height. Refer to «TRIM HEIGHT INSPECTION PROCEDURE»(ref-177943-S37076938052005060800000) .
9. Inspect the steering wheel for excessive drag or poor return due to stiff or rusted linkage or suspension components.
10. Inspect the fuel level. The fuel tank should be full or the vehicle should have a compensating load added.

Give consideration to excess loads, such as tool boxes, sample cases, etc. If normally carried in the vehicle, these items should remain in the vehicle during alignment adjustments. Give consideration also to the condition of the equipment being used for the alignment. Follow the equipment manufacturer's instructions.

Satisfactory vehicle operation may occur over a wide range of alignment settings. However, if the setting exceeds the service allowable specifications, correct the alignment to the service preferred specifications. Refer to Wheel Alignment Specifications .

Perform the following steps in order to measure the front and rear alignment angles

1. Install the alignment equipment according to the manufacturer's instructions.
2. Jounce the front and the rear bumpers 3 times prior to checking the wheel alignment.
3. Measure the alignment angles and record the readings. Important: When performing adjustments to vehicles requiring a 4-wheel alignment, set the rear wheel alignment angles first in order to obtain proper front alignment angles.
4. Adjust alignment angles to vehicle specification, if necessary. Refer to «Wheel Alignment Specifications»(ref-177939-S06445729422005060800000) .

Front Caster Adjustment

Use the following procedure in order to prepare the top strut mounting holes

Scheme 19

Scheme 20

1. Remove the top 3 fasteners from the strut tower.
2. Lift the front of the vehicle by the body in order to separate the strut from the inner wheelhouse. Refer to «LIFTING AND JACKING THE VEHICLE»(ref-176796-S17093977092005051200000) .
3. Pop out the 2 guide pins.
4. Hand file the excess metal in order to make slotted holes.
5. Paint the exposed metal using rust preventative paint or primer.
6. Lower the front of the vehicle.
7. Install the strut attaching fasteners. Do not tighten the fasteners at this time. NOTE: Refer to «FASTENER NOTICE»(ref-175132-S17785009232005041500000) .
8. Move the top of the strut forward or rearward in order to adjust the caster. A 1 mm (0.040 in) position change at the tower is about equal to a 0.1 degree change in the caster. Refer to «Wheel Alignment Specifications»(ref-177939-S06445729422005060800000) . Tighten Tighten the strut fasteners to 47 N.m (35 lb ft).
9. Perform a complete wheel alignment.

Front Camber Adjustment

Tools Required

J 39601 Chamber Adjustment Tool

Scheme 21

1. Raise and support the vehicle. Refer to «LIFTING AND JACKING THE VEHICLE»(ref-176796-S17093977092005051200000) .
2. Remove the tire and wheel. Refer to «TIRE AND WHEEL REMOVAL AND INSTALLATION»(ref-176844-S14435820792005051300000) . Important: Do not allow the bolts to turn. This will ruin the serrated shoulder.
3. Remove the nut and tap the upper and lower bolt from the strut and knuckle.
4. Separate the strut from the knuckle. Important: It is necessary to grind the lower bolt hole on the strut to achieve proper chamber setting. If camber specification is not achieved by this procedure check for bent or worn parts.
5. Using a round file or a die grinder file the inner metal plate to the outside plates diameter.
6. File excess metal to make the slotted holes.
7. Paint the exposed metal with rust preventive paint or primer.
8. Replace the strut to the knuckle.
9. Install both the upper and lower bolts.
10. Do not tighten at this time (leave loose).
11. Install the J 39601 to the bottom strut bolt. NOTE: Refer to «FASTENER NOTICE»(ref-175132-S17785009232005041500000) .
12. Using the J 39601 , set the camber. Refer to «Wheel Alignment Specifications»(ref-177939-S06445729422005060800000) . Tighten Tighten the upper strut to knuckle nut to 225 N.m (166 lb ft).
13. Remove the J 39601. Tighten Tighten the lower strut to knuckle nut to 225 N.m (166 lb ft).
14. Replace the tire and wheel. Refer to «TIRE AND WHEEL REMOVAL AND INSTALLATION»(ref-176844-S14435820792005051300000) .
15. Lower the vehicle.
16. Perform a wheel alignment. Refer to «Wheel Alignment Specifications»(ref-177939-S06445729422005060800000) .

Scheme 22

1. Loosen the lock nuts on the tie rod. NOTE: Refer to «FASTENER NOTICE»(ref-175132-S17785009232005041500000) . NOTE: Care must be taken that the boots are not twisted when rotating the inner tie rods, or damage to the boots may result.
2. Rotate the inner tie rod to adjust the toe. Refer to «Wheel Alignment Specifications»(ref-177939-S06445729422005060800000) . Tighten Tighten the lock nuts to 64 N.m (47 lb ft).
3. Adjust the boots as needed in order to prevent damage.

Rear Toe Adjustment

Important: Complete the left and right rear toe adjustments separately, per wheel. Use the following procedure.

Scheme 23

1. Loosen the inner adjustment link cam nut. NOTE: Refer to «FASTENER NOTICE»(ref-175132-S17785009232005041500000) .
2. In order to adjust the toe, rotate the cam bolt. Refer to «Fastener Tightening Specifications»(ref-177939-S18905501252005060800000) . Tighten Tighten the cam nut (2) to 91 N.m (67 lb ft).
3. Recheck the toe setting after tightening.
4. Readjust the toe setting if necessary. Refer to «Wheel Alignment Specifications»(ref-177939-S06445729422005060800000) .

Scheme 24

Caster is the tilting of the uppermost point of the steering axis either forward or backward, when viewed from the side of the vehicle. A backward tilt is positive (+) and a forward tilt is negative (-). Caster influences directional control of the steering but does not affect the tire wear and is not adjustable on this vehicle. Caster is affected by the vehicle height, therefore it is important to keep the body at its designed height. Overloading the vehicle or a weak or sagging rear spring will affect caster. When the rear of the vehicle is lower than its designated trim height, the front suspension moves to a more positive caster. If the rear of the vehicle is higher than its designated trim height, the front suspension moves to a less positive caster.

With too little positive caster, steering may be touchy at high speed and wheel returnability may be diminished when coming out of a turn. If one wheel has more positive caster than the other, that wheel will pull toward the center of the vehicle. This condition will cause the vehicle to pull or lead to the side with the least amount of positive caster.

Scheme 25

Camber is the tilting of the wheels from the vertical when viewed from the front of the vehicle. When the wheels tilt outward at the top, the camber is positive (+). When the wheel tilts inward at the top, the camber is negative (-). The amount of tilt is measured in degrees from the vertical. Camber settings influence the directional control and the tire wear.

Too much positive camber will result in premature wear on the outside of the tire and cause excessive wear on the suspension parts.

Too much negative camber will result in premature wear on the inside of the tire and cause excessive wear on the suspension parts.

Unequal side-to-side camber of 1 degree or more will cause the vehicle to pull or lead to the side with the most positive camber.

Scheme 26

Toe is a measurement of how much the front and/or rear wheels are turned in or out from a straight-ahead position. When the wheels are turned in, toe is positive (+). When the wheels are turned out, toe is negative (-). The actual amount of toe is normally only a fraction of a degree. The purpose of toe is to ensure that the wheels roll parallel.

Toe also offsets the small deflections of the wheel support system that occur when the vehicle is rolling forward. In other words, with the vehicle standing still and the wheels set with toe-in, the wheels tend to roll parallel on the road when the vehicle is moving.

Improper toe adjustment will cause premature tire wear and cause steering instability.