LEMON Manuals: Even more car manuals for everyone
Home >> Ford >> 2008 >> Expedition EL RWD >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 1 (Four Wheel Drive (4WD) Systems) >> Diagnostic Tests >> Four Wheel Drive (4WD) Systems - 1-Speed Torque-On-Demand >> Pinpoint Tests >> Pinpoint Test G: Straight-line Driveline Wind-up >> Pinpoint Test G: Straight-Line Driveline Wind-Up

Pinpoint Test G: Straight-Line Driveline Wind-Up

WARNING: This page is about a different variant/trim than selected.
NOTE: 4X4 is not intended for driving on hard/dry surfaces; using 4X4 mode while driving on these surfaces may produce noises like intermittent clunking, but will not damage driveline components.
  1. G1 VERIFY THE CONCERN 
    • Drive the vehicle and switch from 4X4 AUTO mode to 4X4 mode. There should be minimal wind-up in 4X4 mode during straight line maneuvers (wind-up in turns is normal; 4X4 mode is not intended for driving on hard/dry surfaces).
    • Is excessive wind-up present? 
    1. YES  : Go to  G2.
    2. NO  : RETURN the vehicle to the customer. ADVISE about correct 4WD system operation and normal vehicle behavior.
  2. G2 CHECK FOR MATCHING WHEEL AND TIRE SIZES 
    • Check the wheel and tire sizes.
    • Do the 4 wheel and tire sizes match? 
    1. YES  : Go to  G3.
    2. NO  : ADVISE the customer that 4WD systems require 4 matched, correctly inflated, correctly maintained tires to operate correctly.
  3. G3 CHECK TIRE WEAR 
    • Check each of the 4 tires for wear.
    • Are the 4 tires worn evenly? 
    1. YES  : Go to  G4.
    2. NO  : ADVISE the customer that 4WD systems require 4 matched, correctly inflated, correctly rotated tires to operate correctly.
  4. G4 CHECK TIRE INFLATION PRESSURE 
    • Check the inflation pressure in each tire. Refer to Vehicle Certification (VC) label.
    • Are the tire inflation pressures correct? 
    1. YES  : Go to  G5.
    2. NO  : ADJUST the tire pressure as necessary. TEST the vehicle for normal operation. ADVISE the customer that 4WD systems require 4 matched, correctly inflated, correctly maintained tires to operate correctly.
  5. G5 CHECK THE FRONT AND REAR AXLE RATIOS 
    1. YES  : RETURN the vehicle to the customer and ADVISE about correct 4WD usage and normal vehicle behavior.
    2. NO  : CHECK the Vehicle Identification Label (VIL). INSTALL the correct axle(s). REFER to REAR DRIVE AXLE/DIFFERENTIAL - FORD 9.75-INCH RING GEAR article and FRONT DRIVE AXLE/DIFFERENTIAL article. TEST the system for normal operation.
scientia non olet · About LEMON Manuals