2004-2008 4x4 Issues??
03-15-2015, 09:08 PM
#1
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2004-2008 4x4 Issues??
I have a 2005 fx4. I think I'm having some problems with my 4x4 and I need some help. It doesn't work all the time, it's like it works when it wants to. If I was to jack up the front end of the truck so that the front 2 tires are off the ground, and I lock the truck in four wheel drive (with the truck running), should I be able to spin the wheels freely?
03-15-2015, 09:27 PM
#2
With the truck on front jacked up, in 4hi the tire will spin kinda easy believe it or not. Key things to pay attention to while doing this are....... When you spin the tire are the front half shafts turning with the tire? Second when you turn the one tire clock wise is the other tire turning counter clock wise?
03-16-2015, 05:17 AM
#3
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For the reason of convienience, Ford (and many other manufacturers) went to a vacuum hub arrangement to lock the front hubs by flipping a switch on the dash. This can be problematic when it is subject to age, road salt, or just abuse by 4 wheeling.
I guess folks just got too lazy from wanting to climb out of their trucks to lock the front hubs.
I'd get familular with this hub system, and check the condition of the vacuum lines and actuators that provide vacuum to them. Its rare that the transfer case has issues, but rather the front hubs locking to the front axles. As mentioned, check that the front axles are turning, along with the front wheels. If the front axles turn, then the transfer case is good; if the front wheels do not turn, then the hubs are not locking to the front axles.
Many hard core 4x4 owners switch the hubs over to manual locking types.
I guess folks just got too lazy from wanting to climb out of their trucks to lock the front hubs.
I'd get familular with this hub system, and check the condition of the vacuum lines and actuators that provide vacuum to them. Its rare that the transfer case has issues, but rather the front hubs locking to the front axles. As mentioned, check that the front axles are turning, along with the front wheels. If the front axles turn, then the transfer case is good; if the front wheels do not turn, then the hubs are not locking to the front axles.
Many hard core 4x4 owners switch the hubs over to manual locking types.
Last edited by Mod (Ret.); 03-16-2015 at 05:23 AM.
03-16-2015, 05:33 AM
#4
Moderator (Ret.)
Also found a nice description of the major components of the 4x4 system used in these year trucks:
Principles of Operation
The electronic shift on the fly (ESOF) system is an electronic shift system that allows the operator to choose between 2 different 4-wheel drive modes as well as 2-wheel drive. The operator can switch between 2WD and 4H mode at speeds up to 88 km/h (55 mph). To engage or disengage 4L range, the vehicle speed must be less than 5 km/h (3 mph), the brake pedal pressed and the transmission must be in NEUTRAL (or the clutch pedal pressed in manual transmission vehicles).
The transfer case is equipped with an electromagnetic clutch which is located inside the case. This clutch is used to synchronize the front driveline. When the mode select switch (MSS) on the instrument panel is turned, the 4x4 module (PCM) activates the electromagnetic clutch and powers the transfer case shift motor. When the shift motor reaches the desired position, as determined by the contact plate position inputs to the 4x4 module (PCM), power to the shift motor will be removed. When the transfer case front and rear output shafts are synchronized, the spring loaded lockup collar mechanically engages the mainshaft hub to the drive sprocket. Finally, the front axle integrated wheel ends (IWEs) are engaged and the electromagnetic clutch is deactivated.
Feature Inputs:
Mode select switch (MSS).
Wheel speeds (via CAN communication).
Contact plate position inputs A, B, C, D (grounded when closed, open circuit when open).
Transmission neutral.
Brake ON/OFF (BOO).
Feature Outputs:
Transfer case synchronization clutch.
Transfer case shift motor relays.
Integrated wheel-end (IWE) vacuum solenoid.
Cluster indicators (via CAN communication).
AWD mode (via CAN communication to PCM).
Integrated Wheel End (IWE) System
The integrated wheel end (IWE) system contains the following:
Vacuum reservoir
IWE solenoid
IWEs (spring loaded vacuum hubs)
Vacuum hoses
Check valve
The IWE system uses vacuum hubs that engage the front wheel hubs to the front halfshafts or disengage the front wheel hubs from the front halfshafts.
The IWE solenoid receives engine vacuum from the vacuum reservoir.
When the 4-wheel drive system is in 2WD mode, the 4x4 module (PCM) supplies a ground path to the IWE solenoid to apply vacuum to the integrated wheel ends (disengaging the front hubs from the front halfshafts). In 4WD mode, the 4x4 module (PCM) does not supply the ground path to the IWE solenoid, vacuum is not applied to the integrated wheel ends and an internal spring keeps the front hubs engaged to the front halfshafts.
Principles of Operation
The electronic shift on the fly (ESOF) system is an electronic shift system that allows the operator to choose between 2 different 4-wheel drive modes as well as 2-wheel drive. The operator can switch between 2WD and 4H mode at speeds up to 88 km/h (55 mph). To engage or disengage 4L range, the vehicle speed must be less than 5 km/h (3 mph), the brake pedal pressed and the transmission must be in NEUTRAL (or the clutch pedal pressed in manual transmission vehicles).
The transfer case is equipped with an electromagnetic clutch which is located inside the case. This clutch is used to synchronize the front driveline. When the mode select switch (MSS) on the instrument panel is turned, the 4x4 module (PCM) activates the electromagnetic clutch and powers the transfer case shift motor. When the shift motor reaches the desired position, as determined by the contact plate position inputs to the 4x4 module (PCM), power to the shift motor will be removed. When the transfer case front and rear output shafts are synchronized, the spring loaded lockup collar mechanically engages the mainshaft hub to the drive sprocket. Finally, the front axle integrated wheel ends (IWEs) are engaged and the electromagnetic clutch is deactivated.
Feature Inputs:
Mode select switch (MSS).
Wheel speeds (via CAN communication).
Contact plate position inputs A, B, C, D (grounded when closed, open circuit when open).
Transmission neutral.
Brake ON/OFF (BOO).
Feature Outputs:
Transfer case synchronization clutch.
Transfer case shift motor relays.
Integrated wheel-end (IWE) vacuum solenoid.
Cluster indicators (via CAN communication).
AWD mode (via CAN communication to PCM).
Integrated Wheel End (IWE) System
The integrated wheel end (IWE) system contains the following:
Vacuum reservoir
IWE solenoid
IWEs (spring loaded vacuum hubs)
Vacuum hoses
Check valve
The IWE system uses vacuum hubs that engage the front wheel hubs to the front halfshafts or disengage the front wheel hubs from the front halfshafts.
The IWE solenoid receives engine vacuum from the vacuum reservoir.
When the 4-wheel drive system is in 2WD mode, the 4x4 module (PCM) supplies a ground path to the IWE solenoid to apply vacuum to the integrated wheel ends (disengaging the front hubs from the front halfshafts). In 4WD mode, the 4x4 module (PCM) does not supply the ground path to the IWE solenoid, vacuum is not applied to the integrated wheel ends and an internal spring keeps the front hubs engaged to the front halfshafts.
Last edited by Mod (Ret.); 03-16-2015 at 05:41 AM.
03-16-2015, 08:49 PM
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Awesome info. All vacuum lines look fine. Im getting vacuum all the way down to the hubs. When i spen the front tires while locked in 4hi, the axles do not turn. When i spen the shaft the axles do turn but the tires do not. I believe water has gotten into the solenoid and went down the vacuum line and ruined my hubs.
03-16-2015, 08:54 PM
#6
