My F150 something strage has happened
A couple of weeks ago the 4x4 worked
now i went out to my truck to look underneth it and i put it in 4wd and turned the front drive shaft and it wasn't engaged so i tried different postiions same thing
it shifts smoothly on the transfer case does the engine have to be running for 4wd to work?
what happened
the truck was in neutral when i did this
do the hubs have to be locked for it to enguage?
the transfer case is a 208
help please
Another thing, i was driving to work last saturday it was raining and i noticed the truck was vibrating so i reached down and the t-case was half way between 2wd and 4hi i pulled it back to 2wd and it stopped
please tell me there is a clutch in the t case that stops the front driveshaft from turning the t-case and only the t-case can drive the drive shaft.
What happened?

 

can any one help?

 

sorry, if you shift the t case into 4x4 and can turn the front shaft without turning the rear shaft, the t case has a problem. probably a broken shift fork in the t case. i have seen a couple with the pin that holds the fork to the shaft broken, but that is rare.



jim

 

how do i fix it?
do i have to rebuild the t-case?
if i need to rebuild the t-case that might take place of my planned engine rebuild this winter

 

how would it be broken if i have only used 4wd once and it worked then?
Was that vibration the tearing up of my tcase?

 

If I remember correctly, that transfer case does not immediately engage when you shift to 4x4. When you shift from 2x4 to 4x4, a fork pushes against a spring. The spring compresses against a nylon collar and the collar attempts to engage the front drive gear. Until you have rotated both the tranny input shaft and the front drive shaft, the transfer case will not go into 4x4.

Because of this setup, the transfer case will not necessarily shift out of 4x4 either. Again, a spring is used to slide the gears apart and they cannot disengage while they are loaded. To disengage the 4x4, sometimes you will find that it might be necessary to drive backwards a few feet while steering the wheels to the left.

Likewise, the locking hubs are also spring loaded. A spring is used to engage and disengage the hubs from the axles.

The whole setup is really a nice design because it prevents the gears from grinding together in the transfer case. A lot of the older (60s & 70s) trucks did a bunch of grinding as you attempted to engage the 4x4. This was because the shifter directly engaged and disengaged the gears in the transfer case.

If you really want to see if the 4x4 is working, lock the front hubs, shift the transfer case into 4x4. Then, get the truck on a soft surface and punch the throttle. You should see spin marks from one of the front wheels. The other option is to drive about 20 feet on a hard surface while steering the truck left or right. You should feel the truck bucking as you do this.

The vibration you felt while driving down the highway was probably bucking due to the truck being in 4x4 while on a hard surface.

 

so i might not of messed it up?
the hubs were unlocked while it was vibrating

 

From what it sounds, the transfer case might actually be what is causing the problem. As Whalerron said though, the best thing to do is engage the 4 x 4 and try going around in a circle, if the truck bucks then you know that the 4 wheel si working. Most likely though since you did not have the Hubs engaged when it started the vibrating then the transfer case is messed up. Try the driving though since the vehicle has to move most the time before the 4 wheel engages.

 

ok heres the story. My dad and I were cutting up a tree that had fallen in our back yard so were were using my truck to carry things from the house and haul the trunk around. so it gets dark and my dad says lets start putting things up (dinner was ready he took off) so i got it loaded up and headed for the house. i got really p!$$ed about the 4x4 not working when it had a week ago and there is a big hill in our yard so i get out lock the hubs put her in N on the t case and 2nd on the tranny and let it spin for a couple of seconds put it in 4hi felt a nudge put it in 2hi and hammered it on the hill and just spun my tires put it in 4hi and hammered it get thrown in the seat. so when i park it i un lock the hubs leave it in 4hi and try to spin the drive shaft and guess what 4X4 WORKS!!!! i guess something got out of mesh or something when i had it half way between 2 and 4 hi.
THANKS for all the help i really appreciate it
DT