94' F-350 manual front wheel drive does not engage. Hubs lubed springs are good?

Check fuses ... I don't know without seeing it but there are actuators that engage when selecting 4 WD.

Call Warn they may have those springs.

Hi,
Do you have auto locking hubs on the front wheels, or manual locking hubs?
If you have auto locking hubs chances are they are not engaging properly and will need to be removed and spline sets checked for broken teeth on locking hub and locking shaft.
If you have manual locking hubs then check that they are firm when turning to engage them in the lock position.If they are light when engaging them to the lock position then they my have broken/worn out the locking hub and spline. Also check that the engaging spring inside the hub has enough tension to engage the hubs they may be broken. If the hub are all ok then you have a problem in the transfer box, where the 4WD lever is not meshing the transfer box properly. Hope this helps, let me know how you get on.

Jason

I would check your fuses or connectors first. It is strange that you get no error codes or warning lights. Nothing! I am assuming that it is Electronic shift on the fly.
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.
There are issues with the 4x4 system I.w.e ends ingesting moisture/water into vacuum actuation system causing no 4x4 or ratcheting outboard I.w.e ends. (Even if you don't go 4x4'n ) pull off vacuum hoses @ I.w.e ends and check for moisture/water/rust also the I.w.e is not part of the wheel bearing itself It is the part on the axle side (inboard) of the spindle. (EVEN DEALERS CAT LISTED WRONG )Many shops just replace the wheel bearing side this may fix the symptom but not the true cause of damaged I.w.e. ! Check with a reputable dealer they should have info on this condition and repair procedure.
Good luck and start with checking the IWE system in the front end.

There are issues with the 4x4 system I.w.e ends ingesting moisture/water into vacuum actuation system causing no 4x4 or ratcheting outboard I.w.e ends. (Even if you don't go 4x4'n ) pull off vacuum hoses @ I.w.e ends and check for moisture/water/rust also the I.w.e is not part of the wheel bearing itself It is the part on the axle side (inboard) of the spindle. (EVEN DEALERS CAT LISTED WRONG)Many shops just replace the wheel bearing side this may fix the symptom but not the true cause of damaged I.w.e. ! Check with a reputable dealer they should have info on this condition and repair procedure.


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 half shafts or disengage the front wheel hubs from the front half shafts.

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 half-shafts). 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 half-shafts.

Good luck and check the vacuum line, start with the simple. Keep me posted, be glad to get your 4wd working again.

There are issues with the 4x4 system I.w.e ends ingesting moisture/water into vacuum actuation system causing no 4x4 or ratcheting outboard I.w.e ends. (Even if you don't go 4x4'n ) pull off vacuum hoses @ I.w.e ends and check for moisture/water/rust also the I.w.e is not part of the wheel bearing itself It is the part on the axle side (inboard) of the spindle. (EVEN DEALERS CAT LISTED WRONG)Many shops just replace the wheel bearing side this may fix the symptom but not the true cause of damaged I.w.e. ! Check with a reputable dealer they should have info on this condition and repair procedure.


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 half shafts or disengage the front wheel hubs from the front half shafts.

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 half-shafts). 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 half-shafts.

It could be several things. The first thing that comes to mind is your u-joint(s) on your front drive shaft. Try turning it by hand, if it has some play in it, it needs to be replaced. There are many other things that can cause your clicking noise tho:

Ball joints
Wheel bearing/wheel hub
Sway bar links

If your clicking noise sounds more like a "electrical" click, Then you might have to try following the noise and give more details about your problem.

Sounds like one of your hubs is sticking and not engaging. You can check them by engaging the hubs and the transfer case and jacking up each front wheel independently if it doesn't spin your good, if it does you found your problem. As far as fixing a hub goes, it may be just dry and need some grease, or there are some very good aftermarket hubs available from Warn.
Hope this helps

Try removing the front drive shaft from the transfer case to the front differential. With the vehicle on 4 jack stands and the front drive shaft removed attempt to place the vehicle into 4 WD. You may have to start the engine if the vehicle uses a vacuum actuator module to engage the front wheels. When you get an indication that the vehicle is in 4WD try turning the front wheels by hand and see it you hear the same grinding noise .... engage the hubs and try again. Usually if the transfer case is ok then the problem is in the front differential or one of the many universal joints that connect all of the elements together. Check the U joints on the front drive shaft for play as well as the U joints on each of the front wheels.

i'm assuming you have a 4 wheel drive. If that is the case then yes cause when your in two wheel drive mode the front is in neutral