I have a 2005 f150 XLT that usually won't go into 4x4 when setting still. If you put it in 4x4 low or high it sounds like the shift motor goes in on transfer case but 4x4 won't work. If you drive down the road a ways it will usually go in (but not always). This is vary unhandy if your stuck. Front vacuum hubs work great engage and disengage every time. Tried a new shift motor on transfer case same results. When it's not working front driveshaft (from transfer case to front differential) is not turning. light on dash always comes right on even though 4x4 is not really engaged. Any ideas? I know 4x4 issues seams to be a common thread but haven't been able to find one that 4x4 works after you drive down the road? I have tried engaging 4x4 in Park, Drive, Natural, Reverse, rocked the truck back and forth but just won't seem to go in. Tonight after getting pulled out drove 1/8 mile down the road and it locked in on its own.

 

Check your transfer case oil, seems like the problem lies in the t case. Could be bearing problems in there etc. Any different noises from the case when engaged?

 

So here is what I found today, oil is clean no metal shavings or metallic look to it at all. As far as noises, all sounds good. When it does go into 4x4 it works great no grinding no winning, nothing! I have ran 50 mph down the road all is well just won't go in when I need it to.

I found that once it goes in it will come in and out every time. I also found if you jack it up foot on the brake truck in gear - switch to 4x4 high - let foot off brake only rear wheels spin, front drive shaft made a 1/4 turn then stoped. Took out of 4x4 - let foot off break - rear wheels turning - switch to 4x4 (yes I know this is not a good idea when front wheels are setting still) front drive shaft and cv shafts turn but as soon as the front hubs lock in all front shafts stop turning.

This tells me its defiantly something in the transfercase. Anyone got any Ideas what it it could be though? Also is there anything I could have done wrong when replacing the shift motor - is there any timing to them?

 

Ok, like I was thinking ,it sure seems like a transfer case issue, it seems to me that as soon as strain ( hubs locking) goes to the t case, it unlocks from the clutch gearing or coupling. It's like the case motor is not fully engaging the contact from the input shaft. Very tough to get exact unless seeing the vehicle but the problem area should be here in the case. A new motor but is the motor turning the full cycle or if it is , is there a problem at the clutching I wonder.

 

Is there a way to check the motor? How far should it turn, I can pull it off and see?

 

With an assistant you could take the motor off and watch the amount of movement when it is switched to 4 hi , 4lo, and 2wd. Just put it back in the orignal position when replacing. For some reason the complete arc of turn of the motor seems to be hanging and not completely turning the selector shaft completely far enough to allow the t case to remain in the intended gear. Have you tried 4 lo. Just to check the operation?

 

Ok I will try that sometime.

I have tried low as well, the funny thing is it it will go in to low gear and still be in 2x4. If you have had it working in 4x4 hi you can go to low and it will work in low. But if you just flip the switch to low it will go into low gear but not lock the front wheels in.

 

I wonder if the front shaft is turning while in 4lo? Check that out. All these questions are important for diagnosing.

 

No sir, it's not turning at all in high or low. I understand the questions very hard to diagnose problems over the Internet​

 

Ok, glad you understand archer guy, your problem is in the transfer case if your shift motor is not moving the selector shaft. Be sure you have voltage to the shift motor of course by testing the appropriate wires when prompted to shift. You said you changed the motor ,so make sure the voltage is getting to it. We now know the problem is indeed at the transfer case and not after that.

 

Sup guys,
So I did vacuum test and everything appears normal. both sides IWE working. I appear to have vacuum. so now with all four tires off the ground I engage 4x4 but my driver side does not spin. I can see small vibrations like it wants to but it appears transfer case not fully engaging the point that the cv connects . any thought???

 

also when i do engage 4 wheel on the ground and attempt to move it feels as if the wheel on driver side is stuck

 

The front differential is an open differential - only one wheel is going to spin. You have to watch the CV shafts to see if they correspond with what the wheels are doing.

Note - vacuum at the IWE disengages it, lack of vacuum allows it to lock.

 

yrs I'm aware of vacuum keeping it in 2 wheel and loss of vacuum locking the IWE . My problem is that once I engage 4wd, I creep forward a few ft then my driver side binds up and if I press gas forward it pushes just what is holding my truck back and makes a loud pop. It appears that my riverside does not operate within the differtial

 

Check the CV shafts.