Technical Service Bulletins
|Publication Date: October 1, 2003|
Some F-150 vehicles built prior to 8/20/2003, may exhibit a Steering Wheel Shimmy/Nibble at 100 km/h (60 MPH) and greater speeds. The condition is felt in the steering wheel as a side-to-side, or rotational, oscillation. When measured (sensor on steering wheel) with an Electronic Vibration Analyzer (EVA), the measured frequency is between 12-16 Hz.
To service, it may be necessary to replace the Steering Gear. Refer to the following Service Procedure.
|NOTE:||BEFORE BEGINNING THIS PROCEDURE, ENSURE THAT THE TIRES DO NOT HAVE FLAT SPOTS. IT MAY BE NECESSARY TO DRIVE THE VEHICLE FOR UP TO 30 MILES TO ELIMINATE THIS CONDITION.|
|NOTE:||FOR 4X2 VEHICLES GO DIRECTLY TO STEP 2.|
- Check the Integrated Wheel End (IWE) on 4×4 units. Raise the front of the vehicle (wheels off the ground), engine running, vehicle in 2WD mode. The front half shafts should not turn when wheels are rotated by hand. If the IWE is functioning correctly proceed to Step 2. If not, refer to the Workshop Manual section 308-07 to repair IWE first. Then proceed to Step 2.
- If road force measurement equipment (Hunter GSP9700/9712, or equivalent) is available, proceed to Step 3. If not, mark the original tire/wheel location on each tire. (i.e. LF, LR, RF, RR) and remove from the vehicle. Check wheel balance, and re-balance as required to achieve a less than 0.25 oz (7g) of imbalance. Reinstall wheels and test drive vehicle. If the condition is corrected return the vehicle to the customer. If not, re-seat the bead on all four tires re-balance as required and test drive vehicle. If the condition is corrected return the vehicle to the customer. If not, proceed to Step 5.
- If road force measurement equipment is available (Hunter GSP9700/9712, or equivalent), measure the tire road force variation on all four tires, following the manufacturer’s instructions and TSB 02-1-6. If any wheel assembly measures more than the values listed below for R1H or R2H then proceed to Step 4. If not proceed to Step 5.
Tire Type R1H R2H P Metric Tires 26 lbs. 18 lbs. LT Tires 39 lbs. 27 lbs.
- Using the tire road force measurement machine, determine the low spot of the wheel run out. Match high point force variation on the tire with the low spot of wheel run out. Re-test the wheel assembly force variation. If the wheel assembly is now acceptable, rebalance and test drive vehicle. If the condition is corrected return the vehicle to the customer. If not, replace the tire and re-check, then rebalance and test drive vehicle. If the condition is corrected return the vehicle to the customer. If not, proceed to Step 5.
- Swap tire/wheel assemblies from front to rear and left to right, re-evaluate the vehicle for every combination. If the condition is corrected return the vehicle to the customer. If not, proceed to Step 6.
- Replace Steering Gear. Refer to the part application chart below.
NOTE: DO NOT REPLACE THE STEERING GEAR IF LATEST LEVEL IS ALREADY INSTALLED. THE LATEST LEVEL CAN BE IDENTIFIED BY A GREEN PAINT DOT ON THE BAR CODE LABEL LOCATED NEAR THE RIGHT SIDE BUSHING BRACKET, AND/OR BY THE FIRST 5 DIGITS OF THE SERIAL NUMBER ON THE BAR CODE LABEL. IF THE FIRST 5 DIGITS OF THE SERIAL NUMBER ARE GREATER THAN: 21003 ALL CREW CAB AND SUPER CAB EXCEPT 133″ WHEEL BASE, OR 21603 ALL REGULAR CAB AND SUPER CAB WITH 133″ WHEEL BASE, THE STEERING GEAR IS THE LATEST LEVEL. PARTS APPLICATION CHART Vehicles Part Number Part Name Super Cab & SuperCrew 4×2 4L3Z-3504-AB Steering Gear Super Cab & SuperCrew 4×4 4L3Z-3504-BB Steering Gear Regular Cab 4×2 4L3Z-3504-CB Steering Gear Regular Cab 4×4 4L3Z-3504-DB Steering Gear
OTHER APPLICABLE ARTICLES: