4 WHEEL DRIVE/ALL WHEEL DRIVE - WITH CONTROL TRAC - SHUDDER ON
ACCELERATION/DECELERATION OR BINDING ON SLOW TURNS
TECHNICAL SERVICE BULLETIN
Reference Number(s): 08-21-11, Date of Issue: October 27, 2008
FORD: 1997-2008 Expedition, Explorer; 2006-2008 F-150; 2007-2008 Explorer Sport Trac; 2008 F-150
LINCOLN: 1998-2008 Navigator; 2003-2005 Aviator
MERCURY:2005 Mountaineer; 2006-2008 Mountaineer
ISSUE
Various 1997-2008 vehicles equipped with either 4 wheel drive or all wheel drive and equipped with control trac may
exhibit a shudder on acceleration/deceleration, binding in slow speed turns or noise from the front driveline and/or
transfer case. The shudder/binding will occur with the vehicle being operated in the awd/auto 4x4 mode. The
shudder/binding may be due to incorrect tire circumference or improper tire inflation pressures.
ACTION
Follow the Service Procedure steps to correct the condition.
SERVICE PROCEDURE
NOTE: THIS DOES NOT APPLY TO 2006-2008 MOUNTAINEER WITH A 4.0L ENGINE OR 2007-
2008 EXPLORER AND SPORT TRAC WITH 20 INCH WHEELS.
NOTE: VEHICLES ON THE LIST MAY REQUIRE REPLACEMENT OF TIRE/S IF THE TIRE
CIRCUMFERENCE AVERAGE BETWEEN THE FRONT AND REAR AXLES ARE
OUTSIDE OF THE 1/2 INCH SPECIFICATION OR IF THE TIRE CIRCUMFERENCE FROM
SIDE TO SIDE ON EITHER AXLE EXCEEDS 1/2 INCH DIFFERENCE, THE SMALLER
TIRE(S) MUST BE REPLACED.
NOTE: REVIEW THE WARRANTY AND POLICY MANUAL FOR FORD MOTOR COMPANY TIRE
REPLACEMENT WARRANTY BEFORE PERFORMING THE SERVICE PROCEDURE.
NOTE: ONLY USE REPLACEMENT TIRE AND WHEEL THAT ARE THE SAME SIZE, LOAD
INDEX, SPEED RATING AND TYPE (SUCH AS P-METRIC VERSUS LT-METRIC OR ALLSEASON
VERSUS ALL-TERRAIN) AS THOSE ORIGINALLY PROVIDED BY FORD. THE
RECOMMENDED TIRE AND WHEEL SIZE MAY BE FOUND ON EITHER THE SAFETY
COMPLIANCE CERTIFICATION LABEL OR THE TIRE LABEL WHICH IS LOCATED ON
THE B-PILLAR OR EDGE OF THE DRIVER'S DOOR.
NOTE: ON SOME 4WD MODELS, THE INITIAL SHIFT FROM 2WD TO 4WD WHILE THE
VEHICLE IS MOVING CAN CAUSE A MOMENTARY CLUNK AND/OR BRIEF
RATCHETING SOUND. THESE SOUNDS ARE NORMAL AS THE FRONT DRIVETRAIN
COMES UP TO SPEED AND IS NOT CAUSE FOR CONCERN.
1. Review the tire label for correct tire size and tire inflation pressures located at the B-Pillar of the drivers door.
2. If the tire size does not match the label, this procedure does not apply, follow normal Workshop Manual (WSM)
diagnostics.
3. If the tire size is correct, ensure tire pressures are within specifications.
4. Raise the vehicle on the hoist, refer to Workshop Manual, Section 100-02.
5. Disconnect all wiring going to the transfer case and road test.
6. Is the shudder/binding present?
a. If the shudder/binding is still present, do not continue with this procedure, continue with WSM normal
diagnostic for 4X4.
b. If the shudder/binding is gone, proceed to Step 7.
7. Raise the vehicle on the hoist and reconnect all the wiring previously disconnected.
8. Using a tailor's tape or flexible measuring tape and measure the circumference of all four (4) tires and record the
measurements. (Fig. 1)
Fig. 1: Measuring Circumference Of Tire
9. Calculate the average of the circumference of the two (2) front tires and calculate the average of the
circumference of the two (2) rear tires. (Fig. 2)
Fig. 2: Calculating Average Circumference Of Tires
10. If the difference between these two averages is greater than 1/2" (12.7 mm), front to back or side to side, replace
the smallest circumference tire(s) and remeasure the tire averages. Refer to WSM, Section 204-04 for tire
replacement.
WARRANTY INFORMATION
NOTE: WARRANTY COVERAGE ELIGIBILITY STARTS WITH 2007 NEW VEHICLE LIMITED
WARRANTY COVERAGE.
WARRANTY INFORMATION
Operation Description Time
082111A 2003-2008 Expedition, Navigator, 2003-2005 Aviator, Explorer, Mountaineer 4X4:
Perform Diagnosis Outlined In Service Procedure And Replace One (1) Tire (Do Not
Use With 1007A)
1.1 Hrs.
082111A 1997-2002 Expedition, 1998-2002 Navigator, 2006-2008 F-150 Harley Davidson,
Mountaineer, 1997-2008 Explorer, 2007-2008 Explorer Sport Trac, And 2008 F-150
Limited 4X4: Perform Diagnosis Outlined In Service Procedure And Replace One
(1) Tire (Do Not Use With 1007A)
1.0 Hr.
082111B 2003-2008 Expedition, Navigator, 2003-2005 Aviator, Explorer, Mountaineer 4X4:
Perform Diagnosis Outlined In Service Procedure And Replace Two (2) Tires. (Do
Not Use With 1007A)
1.4 Hrs.
082111B 1997-2002 Expedition, 1998-2002 Navigator, 2006-2008 F-150 Harley Davidson,
Mountaineer, 1997-2008 Explorer, 2007-2008 Explorer Sport Trac, And 2008 F-150
Limited 4X4: Perform Diagnosis Outlined In Service Procedure And Replace Two
(2) Tires (Do Not Use With 1007A)
1.2 Hrs.
082111C 2003-2008 Expedition, Navigator, 2003-2005 Aviator, Explorer, Mountaineer 4X4
Perform Diagnosis Outlined In Service Procedure And Replace Three (3) Tires (Do
Not Use With 1007A)
1.7 Hrs.
082111C 1997-2002 Expedition, 1998-2002 Navigator, 2006-2008 F-150 Harley Davidson,
Mountaineer, 1997-2008 Explorer, 2007-2008 Explorer Sport Trac, And 2008 F-150
Limited 4X4: Perform Diagnosis Outlined In Service Procedure And Replace Three
(3) Tires (Do Not Use With 1007A)
1.4 Hrs.
DEALER CODING
Basic Part No. Condition Code
7A195 42
