Drive Diagnostic Procedure

1. Ask questions of the customer and find out when the vibration occurs. Find out speed, gear, load (towing). It is also best to ride with the customer and make sure you know exactly what the concern is. Also, use an Electronic Vibration Analyzer (EVA) if available at seat track and pinion to find the source of the concern.





2. Start the vehicle. Does a vibration exist when you perform neutral rpm engine run-ups? Start with Base Test # 1 (Figure 1). If it does, review engine driven components. Also, check fan and transmission torque converter for possible imbalances. Repair these concerns first and retest vehicle.

3. Before driving, review the tires for signs of misalignment or worn suspension parts. Repair and replace worn parts. Drive vehicle after repairing to see if concern is corrected.

4. Drive vehicle verifying that the concern exists, recording all speeds, engine rpms, and what gear it is in when it occurs. Observe if the condition is cyclical or if the condition changes when in 3rd gear or OD. Start with Base Test # 2 (Figure 1).

5. While driving the vehicle, observe if condition changes from cruise to coast or during tip-in or tip-out. If the unit is a 4X4 vehicle, observe any changes from 2H to A4WD and 4H.

6. While driving, place vehicle in Neutral and run up the engine. Then re-engage the transmission. This realigns the internal components of the transmission. If the vibration goes away, call a Ford Authorized Distributor (FAD) for a Ford Quality Remanufactured (FOR) replacement transmission. This should only be a concern on 5.4L Expeditions built before 6/9/1997.

WARNING
1999 4X4 VEHICLES ARE FULL TIME 4-WHEEL DRIVE. THEREFORE, BOTH FRONT AND REAR AXLES WILL NEED TO BE ISOLATED. ALWAYS EXERCISE EXTREME CARE WHEN DOING THIS TEST.

7. After driving the vehicle, it is advisable to run the vehicle on the hoist with the drive wheels raised noting any components that show excessive motion or vibration at the recorded speeds.

8. If the concern is a boom, try to duplicate by slamming the back hatch with all other doors and windows closed. If the boom was duplicated, pull the headliner and try to slide a 3"X5" card between the roof bows. Reattach the roof bows to the roof, using 3M Panel Adhesive Urethane Sealer (or equivalent). If available, use noise reduction material between the bows to quiet the sheet metal of the roof. Re-evaluate concern. If concern is corrected return the vehicle to customer. If it is still present, go to Pinpoint Test AS.

9. Be sure to scan the vehicle for any Diagnostic Trouble Codes (DTCs) that may contribute to poor performance of the powertrain.





























Symptom Chart - Refer to Figures 2-9 for Pinpoint Tests