4x4 - how to use it

I think Ghrit called it, your bound up. try jacking it up to release the tension. Also jeeps need to be backed up a little to disengage 4 wheel after you have shifted.

 

I disagree with both of the above statments, as a guy that has owned several Jeeps not one time have I had one that functioned properly fail to shift out of 4x anything when it was supposed to.

 

Here are a few links to other Liberty owners who have experienced the same problem.

For the most part, there probably isn't anything wrong with your vehicle whatsoever. I'm willing to bet that the biggest problem with the Jeep is that the transfer case has hardly been used and the vehicle doesn't even know what 4WD is. The transfer case might need a fluid change, hard to say exactly without a little more input.

It is not uncommon for a 4x4 that hasn't been used much to have corrosion, dirt/grime causing stuck linkage. However, this only applies to transfer cases with mechanical linkage, not sure if yours is mechanical or electrical. An electronic transfer case uses servos to shift.

Also just keep trying the procedure the owner's manual suggests for engaging/disengaging the transfer case a few times.

4x4 vehicles just tend to have a mind of their own sometimes.

Can a Liberty get stuck in 4WD after you shift back to 2WD? - JeepForum.com

03 Liberty won't shift out of 4x4 - JeepForum.com

2008 liberty won't shift out of 4 low - JeepForum.com

 

I wish I was as lucky as you

 

Agreed but don't tell ghrit that, he might not fit his head through the door.

 

Any 4x4 with auto locking hubs requires to be reversed to disengage. Auto hubs arent really used anymore, certainly not on jeeps but axle bind is real, thats why your owners manuals say not to engage 4x4 on asphalt etc.
I currently own 2 jeep wranglers (94YJ, 98TJ) a 92 cherokee HO and a 06 commander and was a jeep mechanic.

 

Hmm, Maybe I'm wrong, but I believe my F150 4x4 has autolocking hubs and I do not have to go in reverse to disengage. I've used 4x4 a few times, both time's I just switched from 4x4 to 4x2 and rolled forward.

 

Are you talking about your transfer case or the front axle hubs always working every time you've operated them?

Just because your Jeep always work, doesn't mean that somebody with the same model hasn't had to use a little encouragement to get the transfer case or hubs to disengage/engage.

What kind of Jeep do you have?

Being I'm not up on all the latest technology on newer Jeeps.

Do the newer Jeeps have modern technology in their 4WD systems or are they old school?

 

Your vehicle isn't quite the same animal as other 4x4's with auto locking hubs. For starters you do not have a solid front axle, the F150 has an independent front suspension like other manufacturer's have gone to. However, on top of it you have an independent wheel end (IWE). There could be other manufacturer's using the same type of concept for engaging the front axles.

Not all 4x4's operate the same, 4x4 vehicles used to operate much simpler concepts.

In the next posting is an article explaining the different type of components used by Ford.

 

Ford-Wheeling!, Rear-wheel-drive 4x4 operation

By Glen Beanard email
November 01, 2008

Let’s discuss the 4x4 operation on Ford truck platform vehicles. We’ll cover the operation of the parts on the various rear-wheel-drive 4x4 systems. When it comes to Electronic Shift On the Fly (ESOF) and Manual Shift On the Fly (MSOF), much is the same except with MSOF, the driver has to manually push a gear shifter in the floor that is connected by rods to the shift fork inside the transfer case. With shift-on-the-fly four-wheel drive, the vehicle does not need to be stopped and placed into neutral to make the selection between 2x4 and 4x4H. The benefits of this for the driver are that they don’t have to get out and lock in hubs at the wheels, and that they are able to maintain momentum of the vehicle to help them get through a situation.
With ESOF, the driver is given either a dial-type switch or push buttons to select 2x4, 4x4H and 4x4L. The driver must actively command 2x4, 4x4H or 4x4L to engage. For A4WD, the driver has a choice of setting dependent on year and model. Some offer 2x4, A4WD, 4x4H and 4x4L, while some exclude the 2x4 setting and only offer A4WD, 4x4H and 4x4L.
To achieve ESOF, the control module watches for input from the four-wheel-drive mode selector switch. The control module in charge of the system will vary depending on the year and model of the vehicle. The control model in command can be the GEM module, the PCM or a dedicated 4x4 module.
A4WD operation can be achieved either electronically by a control module watching speed sensor inputs and automatically engaging 4x4, or this can be done mechanically using a viscous coupling.
Shift Motor
The shift motor is controlled by the control module through two relays by grounding them. The relays are labeled as clockwise and counterclockwise relays, however they both play a part in making the motor turn in either direction. These relays have a dual pole switch side to them. These types of relays are often referred to as a five-blade relay. The clockwise relay supplies B+ power to the motor to make it turn in the clock while the counterclockwise relay is providing the ground path. This process is inverse for making the motor turn counter clockwise.
The module “knows” the position of the motor based on feedback from the contact plate that forms a series of switches. Most commonly, this contact plate is located on the back of the motor.
Synchronous Clutch
A synchronous clutch is really just a manual transmission synchronizer. The command for 4x4 from the module results in the shift motor, that is very similar in appearance to a window or wiper motor, to be rotated. The electric motor turns a camshaft inside the transfer case. As the shaft turns, it moves a shift fork. The fork then slides a synchronizer ring and hub. That hub then puts pressure on three rings. These rings, called blocking rings, have a conical formation so that the outer ring wedges over the middle ring. Then the middle ring wedges over the inner ring.
The inner ring has tabs that are always locked into a clutch gear that turns a drive sprocket. The drive sprocket and gear just free wheel over the rear output shaft on bushings when in 2x4 mode. But when the blocking rings are forced against one another, the wedging action causes the power from rear output shaft to be transferred to the drive gear causing the drive gear and sprocket to spin up to match the rear output shaft’s speed. Once this happens, the locking collar continuous to move a little more until it slides part way off of the clutch hub and over top of the drive gear.
The outer edge of the drive gear has teeth that mate with the inside edge of the collar so that a solid mechanical lock-up will have occurred from the hub, to the collar, then the gear. Now the drive sprocket is turning a chain which is turning a driven gear mounted on the output shaft and power can then flow to the front axle.
Electromagnetic
There are two different designs of electromagnetic clutches — TOD and standard design. Though there are some mechanical detail differences between the standard and TOD clutch, their basic operation, as viewed from outside the case, is the same.
If the control module sees a speed difference between the front and rear output shafts, it will energize the electromagnetic field of the clutch pack to engage the clutch. When the clutch is engaged, the drive chain then transfers power to the front output shaft. If the vehicle has A4WDR and 4H selector positions on the switch, then the operation of the clutch is the same except for that in 4H position, the clutch will be continuously engaged rather than only being commanded on when a speed difference in shafts is detected.
Viscous Coupling
The viscous coupling is completely mechanical. The clutch housing is a sealed unit. Inside the unit are a series of clutch discs, drive and driven plates. In with the discs are a silicone fluid. As the drive discs turn within the assembly, the fluid is sheered between the drive and driven plates. This action transfers power to the front output shaft via the driven plates regardless of the amount of traction available at the wheels. If the rpm differ enough between the rear output shaft and front output shaft, the fluid will be sheered at a higher rate causing the fluid to heat up. If the fluid gets hot enough, it will expand and cause the plates to be forced together and lock. The unit will unlock as it cools, and the cycle repeats as needed.
Locking Hubs
For many vehicles, the hubs provide a connect and disconnect point between the wheels and the front differential. This connect/disconnect point allows the front axle and differential to rest when not in use and only be active when needed. This reduces the number of moving parts while in 2x4 mode, not only for wear reasons, but to prevent these extra moving parts from unnecessarily lowering fuel economy through increased rolling resistance.
For Ford vehicles, there are three different types of locking hubs. There is also another method of disconnect used that is not performed at the hubs, but rather on the axle assembly, for a total of four different methods of connecting and disconnecting the motion between the front wheels and the front driveshaft.
Manual Hubs
Manual hubs are not found on shift-on-the-fly systems as they require the driver to exit the vehicle and manually turn from “free” to “lock” positions. Inside of a manual locking hub is a dial mechanism, activation spring, inner drive gear, clutch ring, release spring and support. These parts sit inside of a housing that is supported at one end by the dial mechanism and by the support at the other end. The support has bearings in the inner race of it that allow the assembly to freewheel intendant of the axle as needed.
When dialed to the lock position, the cam portion of the dial mechanism presses against the engagement spring. The spring then provides pressure against the inner drive gear. That causes the clutch ring to be pushed so that its inner spines are pushed over the outer spines of the inner drive gear. The outer portion of the clutch ring is splined to the support which is splined and mounted to the dial mechanism that is bolted to the hub/rotor. The inner drive gear is splined to the axle shaft. Now, there is a solid mechanical lock from the axle to the front wheels via the axle to the inner drive gear, to the clutch ring, to the housing, to the dial mechanism to the hub.
When the dial is selected back to “free,” then the pressure of the activation spring is released which allows the release spring to push the clutch ring so that the clutch ring’s inner splines side off of the outer splines of the inner gear. During usage, the clutch ring may be bound to the inner gear due to driveline windup and may not instantly release. That is why the driver may need to back the vehicle up a few feet. That releases the pressure between the splines so that the release spring can do its job.
PVH
Pulse Vacuum Hublock (PVH) hubs have an outward appearance similar to manual hubs. One notable difference is that the two manually selected positions on the hub are “lock” and “auto.” When in “lock,” the hub engages the same way as a manual locking hub. In “auto,” vacuum is used to engage and disengage the hub.
Typically, there will be a PVH solenoid located on the inside of the right front inner fender. For F-series platform vehicles, that will place the solenoid close to the battery. The PVH solenoid contains two coil windings and will have three wires going to it. One wire is B+ voltage and the other two are ground wires with separate circuits to the control module.
When the driver selects 4x4 mode, the control module grounds both coil windings. With both coil windings grounded, the solenoid sends approximately 18 inches of vacuum for gasoline vehicles and about 15 inches of vacuum for diesel vehicles for 45 seconds. Vacuum for diesel vehicles comes from an electric vacuum pump. This vacuum is routed to the hubs.
This high level of vacuum causes the clutch ring to engage the inner gear and lock into position. The vacuum does not need to be continuously applied to this design because the engagement is mechanically held after vacuum is released. When the driver selects 2x4, only one of the coils is energized which sends a lower vacuum to the hubs. This lower vacuum is only about six inches. This lower level of vacuum only partially activates the hub which causes it to partially disengage the clutch ring from the inner gear.
That vacuum times out after 15 seconds. At the end of the 15 seconds, the release spring can then push the clutch ring off of the inner gear. Think of it like the action of a push-button pen. You fully press the button and release to engage the lock that continues to hold the writing tip out even though you aren’t pressing on the button. Then, push the same button only partially compared to before, and release it to let a spring complete the process.
IWE
Integrated Wheel End (IWE) hubs are a vacuum-operated locking hub that differs from the PVH in



operation. With IWE, there are splines on the back of the hub and on the end of the axle halfshaft’s CV joint housing. The IWE locking mechanism mounts between the hub’s splines and the CV joint’s housing splines. The IWE unit consists of vacuum and vent ports, internal spring, vacuum diaphragm, plastic fork and lock-up collar. The default position, no vacuum, 4x4 is engaged by the spring inside the IWE. The spring pushed the lock-up collar from the CV housing splines toward the hub splines so that the lock up collar straddles the air gap between the CV housing splines and the hub splines. This provides a mechanical lock from the axle to the hub through the collar. When 2x4 is selected, vacuum is then applied to the vacuum diaphragm which slides the locking collar off of the hub’s splines. Vacuum is maintained during 2x4 operation. If vacuum is lost for any reason, the hubs will engage.
Vacuum is sent to the hubs by the control module grounding the IWE solenoid. This solenoid is commonly found on the right side of the engine compartment and bolted to the firewall.
Center Axle Disconnect




With a center axle disconnect system, a vacuum motor is mounted to the axle housing near the differential. The vacuum motor has two vacuum chambers — an engage side and a disengage side. There are two vacuum solenoids for this system. One solenoid routes vacuum to the engage side of the vacuum motor, and the other to the disengage side. The vacuum motor operates a shift lever that engages and disengages a collar inside the differential housing. This disengages one axle from the differential, which releases the load from the differential. The load is then released from the front driveshaft.
This concludes the first part of Ford rear-wheel-drive 4x4 systems. As with any system, you can fix it if you first know how it works.

 

You take that truck out and get it dirty yet, it washes off

 

Let me start off by saying, yes I know I'm resurrecting a very old thread, but it was my thread so I reserve the right to do so

Sadly, my truck has seen better days and is going away real soon. An apparent "know issue" with the 4.6L 3V ford engines is that they may not have enough oil pressure to get all the internals good and coated with oil. No oil, means bad things happen. As it turns out my engine started making a bad "ticking" sound. When the stealership had the truck to work on a "known" transmission leak (yet they didn't bother letting owners of the vehicles know about either of these and probably many more issues) I asked about a slight "tick". Mechanic said no noise heard, it's "normal". Fast forward 1.5 months and the noise gets louder. So I take it to a reputable mechanic, not the stealership. They confirmed, the cam phaser is making the ticking and replacing just the passenger side would not guarantee no more problems, replacing both side and a bunch of other part, still no guarantee, but replacing the block, that is the ticket!

sorry, not dropping 6 grand for a block unless I really have to, going to try to get rid of this thing while the engine is still running.

 

They might, but my engine is past that point now. Continued research says I might be able to quiet it down some by replacing the VCT solenoids, $40.00 a pop and an hour of my time. I might have to do that to get a better trade in amount. Dunno at this point. The last month and a half the truck has become a money pit and I need to make it gone.

 

Ahhhh yes 4x4s. Gotta have one feel strange driving anything else,had an all wheel drive santa fe for last couple years but just picked up an old 94 jeep cherokee,have had a hell of a time with it though first alt went then starter,then ign switch under the dash on the column,lost little spring clip that attaches rod to switch(cannot fond one anywhere)so got it rigged up to start with a peice of redi rod once you turn the key,had to rewire whole switch as old harmess had shortedcout and melted.noe sm having problems with idling will rev up to 1500 rpms,soon as u put in gear rpms drop and friggin things stalls.am hoping its something easy but i dont have a garage and its -18 before windchill.hope it warms up a bit this weekend so i cam work onit.it only has to make it until spring as daily vehicle....then its gonna become hunt and fishin wheels [emoji41]

 

OK only from my limited knowledge of 4X4, 1941 Ford Jeep, 1988 Ford Bronco, 1994 Ford F350.

ghrit, the first comment about getting stuck in two wheel drive, I think the problem is that if the hubs are autolocking, they won't auto lock unless the wheel is turning, correct me if I'm wrong.

Limited slip Differentials are good, but they need the special dinosaur oil to be added at 5K miles or somewhere there, if it's not added, then they are not limited.

And why should I lock up my 1988 Bronco, it's on blocks, it's not going anywhere.