Saab - Service: Diagnosis Saab 9-4X I

Tracing Powder or Chalk Test

Clean the weatherstrips and the contact surfaces with cleaning solvent.

1. Apply powder or chalk in an unbroken line to the contact surface of the weatherstrip surrounding the perimeter of the suspected areas.
2. Close the panel completely without slamming the panel. Closing the panel completely presses the weatherstrip firmly against the mating surface.
3. Inspect the applied line on the weatherstrip. The applied line is marred where contact is good. A corresponding imprint is on the mating surfaces.
4. Gaps or irregularities in the powder or the chalk line on the mating surfaces indicate the areas with a poor seal.

Air Pressure Test

1. Mask off both the pressure relief valves.
2. Close all the windows.
3. Turn the vehicles ventilation fan to the on position, with the selector on high speed and in the defrost mode.
4. Unlock and close the doors.
5. Listen for escaping air along the door and the window seals with a stethoscope or a length of heater hose.

Soap Suds or Bubble Test

1. Mask off the pressure relief valves.
2. Close all the windows and the doors.
3. Turn the vehicles ventilation fan to the on position, with the selector on high speed and in the defrost mode.
4. Unlock and close the doors.
5. Apply the soap solution to the potential leak areas.
6. Look for bubbles revealing escaping air.

Waterleak Test Preparation

1. GM vehicles are designed to operate under normal environmental conditions.
2. The design criteria for sealing materials and components takes into consideration the sealing forces required to withstand the natural elements. These specifications cannot take into consideration any artificial conditions, i.e., high pressure car washes.
3. The water leak test procedure has been correlated to the natural elements and will determine the ability of a vehicle to perform under normal operating conditions.
4. The first step in diagnosing a leak is determining the conditions under which a leak occurs. If the general leak area can be found, the exact entry point can be isolated using a water hose or an air hose. Some trim panels or components may need to be removed in order to repair the leak.
5. If leaks are found around a door, door window, rear compartment lid or liftgate area this does not necessarily indicate a bad weatherstrip. An adjustment to these areas may resolve the condition.

Scheme 6

Scheme 7

Scheme 8

1. Pipe (0.5 x 36 in) Reducing Tee, Right Stand Only (0.5 x 0.5 x 0.25 in) Coupling, Left Stand Only, (0.5 in) Tee, Left Stand Only (0.5 in) Cross, Right Stand Only (0.5 in) Pipe to Hose Nipple, Right Stand Only (0.5 in) Female Hose Coupling (5/8 in) Input Hose, Right Stand Only (2.0 ft) (5/8 in diameter) Close Nipple (0.5 in) Cross (0.5 in) with Weld-On Cap (0.5 in) Nipple (0.5 x 12 in) Cap (0.5 in) Female Hose Coupling (5/8 in) Cross Hose (12 ft) (5/8 in diameter) Hose Quick Connect Pipe to Hose Nipple (0.5 in) Pipe (0.5 x 60 in) Water Pressure Gauge, Right Stand Only Full Jet Spray Nozzle, No. 1/2GG-25 or Equivalent Coupling (0.5 in) Assemble the water test stand as shown.
2. Position the stands as shown. The water spray from the stands should overlap the vehicle as shown.
3. Have an assistant inside of the vehicle during the test in order to locate any leaks.
4. The water pressure at the nozzle should maintain a 155 kPa (22 psi), for at least 4 minutes.
5. In order to check the windshield, aim the water spray 30 degrees down and 45 degrees toward the rear. Aim the water towards the corner of the windshield.
6. In order to check the side windows for leaks, position the water stand towards the center of the rear quarter, aiming the water spray 30 degrees down and 45 degrees toward the rear.
7. In order to check the back window, aim the water spray 30 degrees down and 30 degrees toward the front.

Vibration Diagnosis, Starting Point, and Correction

The information in this section on vibration analysis and its remedy is intended to cover various car constructions and configurations. Not all content applies to all cars.

Note. The following steps must be completed before using the analysis tables or the symptom tables.

1. Perform the «VIBRATION ANALYSIS - ROAD TESTING»(ref-652230-S06793674742014082300000) table before using the other Vibration Analysis tables or the Symptom tables in order to effectively diagnose the customer's concern. The use of Vibration Analysis - Road Testing will first provide duplication of virtually any vibration concern and then identify the correct procedure for diagnosing the area of concern which has been duplicated.
2. Review the following Vibration Diagnostic Process.
3. Read through the general descriptions to familiarize yourself with vibration theory and terminology, EL-38792-A Electronic Vibration Analyzer (EVA) 2, and GE-38792-VS Vibrate Software. Reading through the information will help you establish whether or not the problem which the customer described is a potential function property. Refer to the following: «VIBRATION THEORY AND TERMINOLOGY»(ref-652230-S39583406142014082300000) «ELECTRONIC VIBRATION ANALYZER (EVA) DESCRIPTION AND OPERATION»(ref-652230-S26964828032014082300000) «VIBRATE SOFTWARE DESCRIPTION AND OPERATION»(ref-652230-S08194735942014082300000) «REED TACHOMETER DESCRIPTION»(ref-652230-S26233552342014082300000)

Vibration Diagnostic Process

Note. Using the following steps of the vibration diagnostic process will help you to effectively narrow-down and pin-point the search for the specific source of a vibration concern and to arrive at an accurate repair.

1. Gather specific information on the customer's vibration concern.
2. Perform the road testing steps in sequence as identified in Vibration Analysis - Road Testing in order to duplicate the customer's concern and evaluate the symptoms of the concern under changing conditions. Observe what the vibration feels like and what it sounds like. Observe when the symptoms first appear, when they change, and when they cease.
3. Determine if the customer's vibration concern is truly an abnormal condition or something that is potentially an operating characteristic of the vehicle.
4. Systematically eliminate or "rule out" possible vehicle systems.
5. Focus diagnostic efforts on the remaining vehicle system and systematically eliminate or "rule out" possible components of that system.
6. Make a repair on the remaining component, or components, which have not been eliminated systematically, and must therefore be the cause of the vibration.
7. Verify that the customer's concern has been eliminated or at least brought to an acceptable level.
8. Again perform the road testing steps in sequence as identified in Vibration Analysis - Road Testing in order to verify that the vehicle did not have more than one vibration occurring.

Preliminary Visual/Physical Inspection

1. Inspect for aftermarket equipment and modifications which could affect the operation of the vehicle rotating component systems.
2. Inspect the easily accessible or visible components of the vehicle rotating component systems for obvious damage or conditions which could cause the symptom.
3. Inspect the tire inflation pressures for the proper pressure.

Diagnostic Aids

Improper component routing or isolation, or components which are worn or faulty may be the cause of intermittent conditions that are difficult to duplicate. If the vibration concern could not be duplicated by following the steps of the Vibration Diagnostic Process, refer to VIBRATION DIAGNOSTIC AIDS .

Vibration Diagnostic Aids

Note. If you have not reviewed the Diagnostic Starting Point - Vehicle and completed the Vibration Analysis tables as indicated, refer to DIAGNOSTIC STARTING POINT - VEHICLE BEFORE proceeding.

The diagnostic information contained in this Diagnostic Aids section will help you determine the correct course of action to take for the following 4 main conditions. Refer to the appropriate condition from this list

1. «VIBRATION DIAGNOSTIC AIDS - VIBRATION INTERMITTENT OR NOT DUPLICATED»(ref-652230-S10798470152014082300000)
2. «VIBRATION DIAGNOSTIC AIDS - VIBRATION DUPLICATED, COMPONENT NOT IDENTIFIED»(ref-652230-S16778012592014082300000)
3. «VIBRATION DIAGNOSTIC AIDS - VIBRATION DUPLICATED, DIFFICULT TO ISOLATE/BALANCE COMPONENT»(ref-652230-S28423931782014082300000)
4. «VIBRATION DIAGNOSTIC AIDS - VIBRATION DUPLICATED, APPEARS TO BE POTENTIAL OPERATING CHARACTERISTIC»(ref-652230-S10662248622014082300000)

Vibration Diagnostic Aids - Vibration Intermittent or Not Duplicated

Note. If you have not completed the Vibration Analysis tables as indicated and reviewed Vibration Diagnostic Aids, refer to VIBRATION DIAGNOSTIC AIDS BEFORE proceeding.

If you have not been able to duplicate the vibration concern or have only been able to duplicate the concern intermittently, review the following information.

Most vibration concerns that cannot be duplicated are due to either specific conditions that are not present during the duplicating attempts, or due to not following the procedures designed to duplicate concerns properly and in the sequence indicated.

Vibration Diagnostic Aids - Vibration Duplicated, Component Not Identified

Note. If you have not completed the Vibration Analysis tables as indicated and reviewed Vibration Diagnostic Aids, refer to VIBRATION DIAGNOSTIC AIDS BEFORE proceeding.

Vibration Diagnostic Aids - Vibration Duplicated, Difficult to Isolate/Balance Component

Note. If you have not completed the Vibration Analysis tables as indicated and reviewed Vibration Diagnostic Aids, refer to VIBRATION DIAGNOSTIC AIDS BEFORE proceeding.

If you have duplicated the vibration concern but have had difficulty in balancing a component or isolating a component, refer to the following information.

Most vibration concerns are corrected or eliminated through correcting excessive runout of a component, correcting balance of a component, or isolating a component which has come into abnormal contact with another object/component.

Components which can generate a lot of energy and are experiencing excessive runout, imbalance, or ground-out can produce a vibration with a strong enough amplitude that the vibration can transmit to components which are closely related. This type of a condition is usually related to and sensitive to torque-load. The most likely system that could exhibit this type of a condition is the driveline.

Vibration Diagnostic Aids - Vibration Duplicated, Appears to Be Potential Operating Characteristic

Note. If you have not completed the Vibration Analysis tables as indicated and reviewed Vibration Diagnostic Aids, refer to VIBRATION DIAGNOSTIC AIDS BEFORE proceeding.

Symptom Tables

Refer to a Vibration Analysis table as indicated in the following symptom tables, based on the most dominant characteristic of the customer's vibration concern, felt or heard, that is evident during the appropriate condition of the occurrence.

Vibration Symptoms that are Felt

Vibration Symptoms that are Heard

Vehicle-to-Vehicle Diagnostic Comparison

Comparing the customer's vehicle to a KNOWN GOOD vehicle that is essentially identical will help determine if the customer's concern may be characteristic of a vehicle design. To arrive at a valid conclusion, the comparison must be performed under the same conditions, using the same criteria, on a vehicle that has the same option content as the customer's vehicle.

The comparison vehicle must match the customer's vehicle in the following areas

1. Model Year
2. Make
3. Model
4. Body style
5. Powertrain configuration
6. Driveline configuration
7. Final drive ratio
8. Tire/wheel size and type
9. Suspension package
10. Trailering package
11. GVW rating
12. Performance options
13. Luxury options

Scheme 9

The tires on all new production models have a tire performance criteria (TPC) rating number molded on the sidewall. The TPC rating will appear as a 4-digit number preceded by the letters TPC SPEC on the tire wall near the tire size. A replacement tire should have the same TPC rating.

Scheme 10

1. Hard Cornering/Underinflation
2. Incorrect Alignment/Lack of Rotation
3. Incorrect Alignment/Non-uniform Tire
4. Heavy Acceleration/Over inflation
5. Wear Indicator

Inspect the tire and wheel assemblies for the following conditions

1. Unusual wear such as cupping, flat spots, and/or heel-and-toe wear These conditions can cause tire growl, tire howl, slapping noises, and/or vibrations throughout the vehicle.
2. Proper inflation to specifications for the vehicle
3. Bulges in the sidewalls Do not confuse bulges, which are an abnormal condition, with normal ply splices which are commonly seen as indentations in the sidewall.
4. Bent rim flanges

Scheme 11

Scheme 12

1. Raise and support the vehicle.
2. Closely inspect each tire for proper and even bead seating.
3. If any of the tire beads were not properly or evenly seated, reset the tire. The continue to step 4. See «TIRE AND WHEEL REMOVAL AND INSTALLATION»(ref-652234-S18162824462014082300000) .
4. Wrap the circumference of each tire with tape (1) in the center tread area. Wrapping the tread with tape allows for a smooth and accurate reading of radial runout to be obtained.
5. Position the dial indicator on the taped portion of the tire tread such that the dial indicator is perpendicular to the tire tread surface.
6. Slowly rotate the tire and wheel assembly one complete revolution in order to find the low spot.
7. Set the dial indicator to zero at the low spot.
8. Slowly rotate the tire and wheel assembly one more complete revolution and measure the total amount of radial runout. Specification Maximum tire and wheel assembly radial runout - measured on-vehicle: 1.52 mm (0.060 in)
9. Position the dial indicator on a smooth portion of the tire sidewall, as close to the tread as possible, such that the dial indicator is perpendicular to the tire sidewall surface.
10. Slowly rotate the tire and wheel assembly one complete revolution in order to find the low spot. Ignore any jumps or dips due to sidewall splices.
11. Set the dial indicator to zero at the low spot.
12. Slowly rotate the tire and wheel assembly one more complete revolution and measure the total amount of lateral runout. Ignore any jumps or dips due to sidewall splices and attain an average runout measurement. Specification Maximum tire and wheel assembly lateral runout - measured on-vehicle: 1.52 mm (0.060 in)
13. Repeat steps 4 through 12 until all of the tire and wheel assembly radial and lateral runout measurements have been taken.
14. Lower the vehicle.

Scheme 13

Scheme 14

Scheme 15

1. Raise and support the vehicle.
2. Mark the location of the wheels to the wheel studs and mark the specific vehicle position on each tire and wheel - LF, LR, RF, RR.
3. Remove the tire and wheel assemblies from the vehicle.
4. Closely inspect each tire for proper and even bead seating.
5. If any of the tire beads were not properly or evenly seated, reset the tire. The continue to step 6. See «TIRE AND WHEEL REMOVAL AND INSTALLATION»(ref-652234-S18162824462014082300000) .
6. Mount a tire and wheel assembly on a spin-type wheel balancer. Locate the tire and wheel assembly on the balancer with a cone through the back side of the center pilot hole.
7. Wrap the outer circumference of each tire with tape (1) in the center tread area. Wrapping the tread with tape allows for a smooth and accurate reading of radial runout to be obtained.
8. Position the dial indicator on the taped portion of the tire tread such that the dial indicator is perpendicular to the tire tread surface.
9. Slowly rotate the tire and wheel assembly one complete revolution in order to find the low spot.
10. Set the dial indicator to zero at the low spot.
11. Slowly rotate the tire and wheel assembly one more complete revolution and measure the total amount of radial runout. Specification Maximum tire and wheel assembly radial runout - measured off-vehicle: 1.27 mm (0.050 in)
12. Position the dial indicator on a smooth portion of the tire sidewall, as close to the tread as possible, such that the dial indicator is perpendicular to the tire sidewall surface.
13. Slowly rotate the tire and wheel assembly one complete revolution in order to find the low spot. Ignore any jumps or dips due to sidewall splices.
14. Set the dial indicator to zero at the low spot.
15. Slowly rotate the tire and wheel assembly one more complete revolution and measure the total amount of lateral runout. Ignore any jumps or dips due to sidewall splices and attain an average runout measurement. Specification Maximum tire and wheel assembly lateral runout - measured off-vehicle: 1.27 mm (0.050 in)
16. Repeat steps 6 through 15 until all of the tire and wheel assembly radial and lateral runout measurements have been taken.
17. If ANY of the tire and wheel assembly runout measurements were NOT within specifications, proceed to step 19 .
18. If ALL of the tire and wheel assembly runout measurements WERE within specifications, then the off-vehicle tire and wheel assembly runout is considered acceptable.
19. Position the dial indicator on the horizontal outer surface of the wheel rim flange - with the tire still mounted - such that the dial indicator is perpendicular to the rim flange surface. Wheel runout should be measured on both the inboard and outboard rim flanges, unless wheel design will not permit. Ignore any jumps or dips due to paint drips, chips, or welds.
20. Slowly rotate the tire and wheel assembly one complete revolution in order to find the low spot.
21. Set the dial indicator to zero at the low spot.
22. Slowly rotate the tire and wheel assembly one more complete revolution and measure the total amount of wheel radial runout. Specification Maximum aluminum wheel radial runout - measured off-vehicle, tire mounted: 0.762 mm (0.030 in) Maximum steel wheel radial runout - measured off-vehicle, tire mounted: 1.015 mm (0.040 in)

Scheme 16

1. Position the dial indicator on the vertical outer surface of the wheel rim flange - with the tire still mounted - such that the dial indicator is perpendicular to the rim flange surface. Wheel runout should be measured on both the inboard and outboard rim flanges, unless wheel design will not permit. Ignore any jumps or dips due to paint drips, chips, or welds.
2. Slowly rotate the tire and wheel assembly one complete revolution in order to find the low spot.
3. Set the dial indicator to zero at the low spot.
4. Slowly rotate the tire and wheel assembly one more complete revolution and measure the total amount of wheel lateral runout. Specification Maximum aluminum wheel lateral runout - measured off-vehicle, tire mounted: 0.762 mm (0.030 in) Maximum steel wheel lateral runout - measured off-vehicle, tire mounted: 1.143 mm (0.045 in)

1. Repeat steps 19 through 26 until all of the wheel radial and lateral runout measurements have been taken on each of the - tire and wheel - assemblies with assembly runout measurements which were NOT within specifications.
2. If any of the wheel runout measurements were NOT within specifications, proceed to Measuring Wheel Runout - Tire Dismounted.
3. For any of the wheel runout measurements which were within specifications while the tire and wheel assembly runout measurements were not within specifications, replace the tire. Then balance the complete wheel. Refer to «TIRE AND WHEEL ASSEMBLY BALANCING - OFF VEHICLE»(ref-652230-S27094584702014082300000) .
4. After replacement of any tires, always re-measure the runout of the affected tire and wheel assembly, or assemblies.
5. Using the matchmarks made prior to removal, install the tire and wheel assemblies to the vehicle.
6. Lower the vehicle.

Scheme 17

1. On the tire and wheel assembly, or assemblies with wheel runout measurements - tire mounted - which were NOT within specifications, mark each tire and wheel in relation to each other.
2. Dismount the tire from the rim. Refer to «TIRE DISMOUNTING AND MOUNTING»(ref-652234-S11480235382014082300000) .
3. Mount a tire and wheel assembly on a spin-type wheel balancer.
4. Locate the tire and wheel assembly on the balancer with a cone through the back side of the center pilot hole.
5. Position the dial indicator on the horizontal inner surface of the wheel rim flange - with the tire dismounted - such that the dial indicator is perpendicular to the rim flange surface. Wheel runout should be measured on both the inboard and outboard rim flanges. Ignore any jumps or dips due to paint drips, chips, or welds.
6. Slowly rotate the wheel one complete revolution in order to find the low spot.
7. Set the dial indicator to zero at the low spot.
8. Slowly rotate the wheel one more complete revolution and measure the total amount of wheel radial runout. Specification Maximum aluminum wheel radial runout - measured off-vehicle, tire dismounted: 0.762 mm (0.030 in) Maximum steel wheel radial runout - measured off-vehicle, tire dismounted: 1.015 mm (0.040 in)

Scheme 18

1. Position the dial indicator on the vertical inner surface of the wheel rim flange - with the tire dismounted - such that the dial indicator is perpendicular to the rim flange surface. Wheel runout should be measured on both the inboard and outboard rim flanges. Ignore any jumps or dips due to paint drips, chips, or welds.
2. Slowly rotate the wheel one complete revolution in order to find the low spot.
3. Set the dial indicator to zero at the low spot.
4. Slowly rotate the wheel one more complete revolution and measure the total amount of wheel lateral runout. Specification Maximum aluminum wheel lateral runout - measured off-vehicle, tire dismounted: 0.762 mm (0.030 in) Maximum steel wheel lateral runout - measured off-vehicle, tire dismounted: 1.143 mm (0.045 in)

1. Repeat steps 2 through 12 until all of the wheel radial and lateral runout measurements - tire dismounted - have been taken on each wheel with runout measurements - tire mounted - which were NOT within specifications.
2. If any of the wheel runout measurements - tire dismounted - were NOT within specifications, replace the wheel. Always measure the runout of any replacement wheels.
3. For any of the wheel runout measurements which were within specifications while the tire and wheel assembly runout measurements were not within specifications, replace the tire. Then balance the complete wheel. Refer to «TIRE AND WHEEL ASSEMBLY BALANCING - OFF VEHICLE»(ref-652230-S27094584702014082300000) .
4. Install the tire/tires on the wheel/wheels using the markings made earlier. Then balance the complete wheel or wheels. Refer to «TIRE AND WHEEL ASSEMBLY BALANCING - OFF VEHICLE»(ref-652230-S27094584702014082300000) . Always measure the runout of any of the tire and wheel assemblies which have had the tires dismounted and mounted.
5. Using the matchmarks made prior to removal, install the tire and wheel assemblies to the vehicle.
6. Lower the vehicle.

Scheme 19

1. Support the vehicle drive axle on a suitable hoist. Refer to «LIFTING AND JACKING THE VEHICLE»(ref-652230-S26645367622014082300000) .
2. Remove the tire and wheel assemblies from the drive axle. Refer to «TIRE AND WHEEL REMOVAL AND INSTALLATION»(ref-652234-S18162824462014082300000) .
3. Refer to «WORK STALL TEST WARNING»(ref-652229-S01790406802014082300000) . Reinstall the wheel nuts in order to retain the brake rotors.
4. Run the vehicle at the concern speed while inspecting for the presence of the vibration.
5. WARNING: Do not depress the brake pedal with the brake rotors and/or the brake drums removed, or with the brake calipers repositioned away from the brake rotors, or damage to the brake system may result. If the vibration is still present, remove the rotors from the drive axle, then run the vehicle back to the concern speed.
6. If the vibration is eliminated when the brake rotors are removed from the drive axle, repeat the test with one rotor installed at a time. Replace the rotor that is causing or contributing to the vibration concern.
7. If a brake rotor was replaced as a result of following the previous steps, or if necessary to confirm the results obtained during the previous steps, and/or to check the non-drive axle components, perform the following: 7.1. Mount the brake rotor/drum on a balancer in the same manner as a tire and wheel assembly. 7.2. NOTE: Check brake rotors/drums for static imbalance only; ignore the dynamic imbalance readings. Inspect the rotor/drum for static imbalance.

There is not a set tolerance for brake rotor/drum static imbalance. However, any brake rotor/drum measured in this same manner which has a difference over 21 g (3/4 may have the potential to cause or contribute to vibrations. Rotors/drums suspected of causing or contributing to a vibration should be replaced. Any rotor/drum that is replaced should be checked for imbalance in the same manner.

Hub/Axle Flange and Wheel Stud Runout Inspection

Special Tools

GE-8001 Dial Indicator Set, or equivalent

Scheme 20

Scheme 21

1. Raise and support the vehicle. Refer to «LIFTING AND JACKING THE VEHICLE»(ref-652230-S26645367622014082300000) .
2. Mark the location of the wheels to the wheel studs and mark the specific vehicle position on each tire and wheel - LF, LR, RF, RR.
3. Remove the tire and wheel assemblies from the vehicle. Refer to «TIRE AND WHEEL REMOVAL AND INSTALLATION»(ref-652234-S18162824462014082300000) .
4. Remove the brake rotors and/or brake drums from the vehicle. Clean the mounting surfaces of the brake rotors, the brake drums, if equipped, and the hub/axle flanges of any loose debris, rust, and corrosion.
5. Position the GE-8001 Dial Indicator Set, or equivalent, on the machined surface of the wheel hub/axle flange outside of the wheel studs.
6. Rotate the hub one complete revolution in order to find the low spot.
7. Set the GE-8001 Dial Indicator Set, or equivalent, to zero at the low spot.
8. Rotate the hub one more complete revolution and measure the total amount of wheel hub/axle flange runout. Specification - Guideline Wheel hub/axle flange runout tolerance guideline: 0.132 mm (0.005 in)
9. If the runout of the wheel hub/axle flange IS within specification and the vehicle is equipped with wheel studs, proceed to step 13 .
10. If the runout of the wheel hub/axle flange IS within specification and the vehicle is equipped with wheel bolts, proceed to step 19 .
11. If the runout of the wheel hub/axle flange is marginal, the wheel hub may or may not be the source of the disturbance.
12. If the runout of the wheel hub/axle flange is excessive, replace the wheel hub/axle flange. Measure the runout of the new wheel hub/axle flange.
13. Position the GE-8001 Dial Indicator Set, or equivalent, in order to contact the wheel mounting studs. Measure the stud runout as close to the flange as possible.
14. Turn the hub one complete revolution to register on each of the wheel studs.
15. Zero the GE-8001 Dial Indicator Set, or equivalent, on the lowest stud.
16. Rotate the hub one more complete revolution and measure the total amount of wheel stud - stud circle - runout. Specification - Guideline Wheel stud runout tolerance guideline: 0.254 mm (0.010 in)
17. If the runout of the wheel studs - stud circle - is marginal, the wheel studs may or may not be contributing to the disturbance.
18. If the runout of the wheel studs - stud circle - is excessive, replace the wheel studs as necessary. Measure the runout of the new wheel studs.
19. Inspect the threads and the tapered seat portion on each of the wheel bolts for damage.
20. Wheel bolts exibiting damaged threads and/or damaged tapered seats require replacement.
21. Place the threaded portion of each wheel bolt along a straight edge to inspect for straightness.
22. Wheel bolts that are not straight require replacement.

Isolation Test Procedure

Perform the following test in order to determine if force variation is present in the vehicle.

1. Substitute a set of KNOWN GOOD, pre-tested tire and wheel assemblies of the same size and type for the suspected original assemblies. Refer to «TIRE AND WHEEL REMOVAL AND INSTALLATION»(ref-652234-S18162824462014082300000) .
2. Road test the vehicle to determine if the vibration is still present. Refer to «VIBRATION ANALYSIS - ROAD TESTING»(ref-652230-S06793674742014082300000) .
3. If the vibration is still present while using the known good set of tire and wheel assemblies, then force variation is not the cause of the vibration.
4. If the vibration is eliminated when using the known good set of tire and wheel assemblies, install one of the original tire and wheel assemblies using the matchmarks made prior to removal. Refer to «TIRE AND WHEEL REMOVAL AND INSTALLATION»(ref-652234-S18162824462014082300000) . Road test the vehicle to determine if the vibration has returned. Refer to «VIBRATION ANALYSIS - ROAD TESTING»(ref-652230-S06793674742014082300000) .
5. Continue the process of installing the original tire and wheel assemblies one at a time, then road testing the vehicle, until the tire and wheel assembly, or assemblies which is causing the vibration has been identified.
6. Replace the tire, or tires on the vibration-causing tire and wheel assembly, or assemblies, then balance the assembly, or assemblies. Refer to «TIRE AND WHEEL ASSEMBLY BALANCING - OFF VEHICLE»(ref-652230-S27094584702014082300000) .

Propeller Shaft Phasing Inspection

Special Tools

J-23498-A Driveshaft Inclinometer, or equivalent

Note. This inspection procedure is intended to inspect propeller shaft systems with 2 or 3 U-joints only.

Correct phasing of a propeller shaft refers to the relative alignment of the U-joint yoke flanges to each other to provide proper cancellation of the U-joints. The yokes should be directly aligned to within the range specified in this procedure.

Scheme 22

1. Raise and support the vehicle. On vehicles with solid axles, ensure that the drive axle is supported at ride height - vehicle body supported by suspension components. Ensure the wheels are free to rotate. Refer to «LIFTING AND JACKING THE VEHICLE»(ref-652230-S26645367622014082300000) .
2. Place the transmission into NEUTRAL.
3. Clean any corrosion or foreign material from the U-joint bearing caps.
4. Remove any of the U-joint bearing cap snap rings that may interfere with the correct placement of the J-23498-A Driveshaft Inclinometer, or equivalent.
5. Inspect the prop shaft for proper phasing. 5.1. Rotate the prop shaft or shafts to align the shaft yoke flanges vertically. 5.2. Install J-23498-A drive shaft inclinometer or corresponding on the bearing cap on the front u-joint, the yoke for which is now aligned vertically. J-23498-A inclinometer for drive shaft or equivalent should be aligned perpendicular to the propeller shaft. 5.3. Set the indicator line on the J-23498-A Driveshaft Inclinometer, or equivalent to 15, the horizontal reference. 5.4. Rotate the propeller shaft slightly to center the bubble to the indicator. The U-joint is now vertical. 5.5. Without disturbing the setting on the J-23498-A Driveshaft Inclinometer, or equivalent, remove the J-23498-A Driveshaft Inclinometer, or equivalent from the rear U-joint bearing cap. 5.6. Install the J-23498-A Driveshaft Inclinometer, or equivalent to the lower U-joint bearing cap of the front U-joint of the same shaft. 5.7. Observe and record the reading of the front U-joint with the J-23498-A Driveshaft Inclinometer, or equivalent still set to 15, the horizontal reference.
6. For prop systems with 3 U-joints, rotate the shafts 1/4 turn and repeat steps 5.1-5.7 for the other prop shaft.
7. If the difference between the front and rear U-joints of a welded yoke propeller shaft is 3 degrees or less, the propeller shaft is properly phased.
8. If the difference between the front and rear U-joints of a welded-yoke propeller shaft is greater than 3 degrees, the propeller shaft is either constructed improperly, or damaged from twisting. Refer to «PROPELLER SHAFT PHASING CORRECTION»(ref-652230-S22009880042014082300000) .
9. If the difference between the welded yoke and slip yoke of a propeller shaft is 1.5 degrees or less, the prop shaft is properly phased.
10. If the difference between the welded yoke and slip yoke of a propeller shaft is greater than 1.5 degrees, the propeller shaft is either constructed improperly, or damaged from twisting. Refer to «PROPELLER SHAFT PHASING CORRECTION»(ref-652230-S22009880042014082300000) .