Pinpoint Test A: Mechanical Shift Functional Test
WARNING: This page is about a different car, the 2005 Ford Pickup, 2005 Ford F550 Super Duty, 2005 Ford F450 Super Duty, and 2005 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
- A1 CHECK FOR 2WD INDICATED
- With the vehicle stationary, make sure the transmission is in NEUTRAL with your foot on the brake pedal.
- Key in ON position.
- Shift the transfer case selector lever to 2WD.
- Observe both the 4x4 and 4x4 LOW indicators.
- Are both indicators off?
- Yes : GO to A2.
- No : GO to INSTRUMENT CLUSTER to diagnose the instrument cluster.
- A2 CHECK THE HUBLOCK OPERATION
- Turn the hublocks to the LOCK position.
- Can the hublocks turn to the LOCK position?
- Yes : GO to A3.
- No : INSTALL a new hublock as necessary. REFER to HUBLOCK in this section.
- A3 VERIFY SHIFT TO 4x4
- With the vehicle stationary, shift the transmission to NEUTRAL.
- Shift the transfer case selector lever to the 4x4 position.
- Did the transfer case selector lever shift to the 4x4 position?
- Yes : GO to A5.
- No : GO to A4.
- A4 ATTEMPT TO MECHANICALLY ASSIST 4x4 SHIFT
- Allow the vehicle to roll forward.
- Shift the transfer case selector lever to the 4x4 position.
- Did the transfer case selector lever shift to the 4x4 position?
- Yes : GO to A5.
- No : 4x4 will not engage. GO to SYMPTOM CHART .
- A5 CHECK FOR MECHANICAL ENGAGEMENT OF 4x4
- Drive the vehicle in tight turns on a hard surface.
- Check for the presence of driveline wind-up and tire scuff.
- Is driveline wind-up and tire scuff present?
- Yes : GO to A6.
- No : 4x4 did not mechanically engage. GO to PINPOINT TEST B .
- A6 CHECK THE 4x4 INDICATOR
- Observe the 4x4 indicator.
- Is the 4x4 indicator illuminated?
- Yes : GO to A7.
- No : GO to INSTRUMENT CLUSTER .
- A7 VERIFY SHIFT TO 4x4 LOW
- Apply the brake.
- With the vehicle stationary, shift the transmission to NEUTRAL.
- Shift the transfer case selector lever to 4x4 LOW.
- Did the transfer case selector lever shift to 4x4 LOW?
- Yes : GO to A9.
- No : GO to A8.
- A8 ATTEMPT TO MECHANICALLY ASSIST 4x4 LOW SHIFT
- Allow the vehicle to roll forward.
- Shift the transfer case selector lever to the 4x4 LOW position.
- Did the transfer case selector lever shift to the 4x4 LOW position?
- Yes : GO to A9.
- No : 4x4 LOW will not engage. GO to SYMPTOM CHART .
- A9 CHECK FOR MECHANICAL ENGAGEMENT OF 4x4 LOW
- Execute tight turns on a hard surface.
- Check for the presence of driveline wind-up, tire scuff and limited vehicle speed.
- Is driveline wind-up and tire scuff present?
NOTE: Driveline wind-up and tire scuff is present in both 4x4 and 4x4 LOW. However, vehicle speed is severely limited in 4x4 LOW.- Yes : GO to A10.
- No : 4x4 LOW did not mechanically engage. GO to SYMPTOM CHART .
- A10 CHECK THE 4x4 LOW INDICATOR
- Observe the 4x4 LOW indicator.
- Is the 4x4 LOW indicator illuminated?
- Yes : GO to A11.
- No : GO to INSTRUMENT CLUSTER .
- A11 CHECK THE SHIFT FROM 4x4 LOW TO 2WD
- With the vehicle stationary, shift the transfer case selector lever to the 2WD position.
- Did the selector lever shift to the 2WD position?
- Yes : GO to A13.
- No : GO to A12.
- A12 ATTEMPT TO MECHANICALLY ASSIST 4x4 LOW DISENGAGEMENT
- Allow the vehicle to roll forward to eliminate blockage or driveline wind-up.
- Shift the transfer case selector lever to the 2WD position.
- Did the selector lever shift to 2WD position?
- Yes : GO to A13.
- No : 4x4 LOW will not disengage. GO to SYMPTOM CHART .
- A13 CHECK THE HUBLOCK RETURN TO FREE
- Turn the hublocks to FREE.
- Will the hublocks turn to the FREE position?
- Yes : GO to A14.
- No : INSTALL a new hublock. REFER to HUBLOCK in this section.
- A14 VERIFY HUBLOCKS WILL DISENGAGE IN THE FREE POSITION
- Lift and support the vehicle so the front tires are a few inches off the ground. Refer to JACKING AND LIFTING .
- Rotate the left front tire while observing the left front axle shaft and universal joint.
- Rotate the right front tire while observing the right front axle shaft and universal joint.
- Does either axle shaft rotate?
- Yes : INSTALL a new hublock on the axle that rotated. REFER to HUBLOCK in this section
- No : GO to A15.
- A15 VERIFY THE TRANSFER CASE MECHANICALLY DISENGAGED
- Engage the parking brake.
- Rotate the front driveshaft.
- Does the front driveshaft rotate?
- Yes : The 4x4 system is operating correctly. INSTRUCT the customer on correct operation.
- No : The transfer case did not disengage. REPAIR the transfer case as necessary. REFER to TRANSFER CASE .