Just to muddy up the water a little. Yes, that is what every owners manual, in every 4X4 I've had said. But, and just for conversation sake, the two Power Wagons I had, both had that half baked fulltime system Mopar came out with about '76 or so. If you were in lo lock, as they called it, and wanted to go to 2Hi, with the auto trans, and went to neutral, that thing would grind almost to oblivion. In real life, I had to stop, put the tranny in park, then shift into Hi, or Hi lock, then put the tranny back in gear. Just some useless info from my minds archives.

 

I didn't mention that step did I, I knew I would hear about it lol. Mostly because it won't allow you to come out of 4-low while going in drive unless you stop-then-shifit-to-neutral or are at a very slight roll in neautral and its very easy to tell if you do something wrong if you tried doing it improperly. To be more clear of what I meant, sometimes I have to repeat the process of locking into 4x4 then back to 4x2 when I have used 4-low. I always thought it could be how level the ground is where your sitting that affects the shift and how much load is on the gears.

 

these gen trucks id think there was no hubs

 

To the OP, the 4WD should disengage at higher speeds than what you're observing with your truck. Something likely is not working just right. Have somebody look at it before the problem gets worse because now is the winter season when you rely on 4WD working for you.

 

I have an appointment for Monday to check it out, as well as the intermittent check engine code. I was waiting for a light snow day, because I use it for a little bit of plowing. Maybe the weather report will be halfway accurate this time

 

I know it's a PITA, but just out of curiosity. Try shifting it back into 2WD by stopping, going to park, then shift. I realize since SOF is one of the attractions that should work correctly, it may be something to try for trouble shooting the problem. Please let us know what is found out.

 

Okay, time for an update on my appointments. On Monday, I dropped it off after fully describing my concern. When I picked up, I talked to the tech and he basically lied to me, trying to CHA. He told me that up on the lift, the front wheels,as well as the axles and front driveshaft, would stop turning when shifting from 4wd high to 2wd. We then took it on a test drive and agreed that he maybe he could work on it some more. Unfortunately, I needed it back for the night, so agreed to bring it back on Tuesday. On Tuesday, I dropped it off and said I would be satisfied if they showed me, on the lift, that the shaft stopped rotating after changing back to 2wd. He agreed that it was not stopping, but could not find anything specific as to the proper operation in the manual. They pushed the question up to the engineers and this is their response, I guess this is the out they were looking for and told me it was normal. I don't know what an IWE is, but this is not "residual movement" , it is driven movement. This is not over yet . I talked to two other mechanics where I used to work at AT&T, and they told me it sounds like the servo is not working properly. They suggested a different dealership, where they know there are some very good truck mechanics. I will go to that location and explain my dilemma, and do a little name dropping from my AT&T buddies. Only thing I have to show for all this is a loss of my time and the loss of a hundred dollar bill for them to say it is fine.

 

I have had 3 "shift on the fly" 4wd trucks- 2 Fords and 1 Chevy. I know this doesn't make me an expert. The total miles on these 3 trucks together is about 340,000 and I had absolutely no repairs on any of them. I did early on have a Ford that would sometimes hang in 4wd when going from 4wd high to 2wd high. All of my shifting was at 10 MPH + or - a couple of MPH. I learned real quick that if I shifted transmission into nuetral (to unload the gears) and then shifted into or out of 4wd I never again had a hangup or the slightest bit of any kind of gear noise. All of these shifts are into or out of 2wd and 4wd High. On all 3 of these trucks shifting from 4wd lo to 4wd high sitting totally still would result in a slight gear grind. I also tried at barely rolling (less than 1 MPH) I still would get a grind. So, I decided to always shift into or out of 2wd/4wd to do it this way- With the engine turned off I would select from 4wd high into 4wd lo and then start engine, never again heard a grind. These 3 trucks are 1983 Bronco, 1994 Chevy truck and a 2010 F-150 truck.

Oldstuff

 

To prove if it is residual power or pulling power...
Maybe raise the rear diff off the ground with a floor jack that has wheels. Slowly move it with front wheels pulling (on smooth surface) then switch. If the truck stops its not pulling. Or possibly put it on a lift with friction to the front wheels like them barely touching the floor. ??? There has to be a way to do it safely.

 

I live in Alaska so my circumstances might be different. But here is what I have figured of from living up here through a winter. Roads are always covered in ice so depending on temp and weather I go between 2wd and 4wd. I shift on the fly to 4wd but I do so after I have let off the gas and make sure I am heading straight. I have had two times that have caused problems, first was trying to shift out of 4wd while accelerating, it would not shift. Second time it was about -40F and I was sliding all over the place so I decided to put it into 4wd as I was headed around a corner, I did not know it did not engage but the next stop sign I came to it made a god-aweful grinding noise trying to go into 4wd so I immediately switched it back to 2wd.

Not saying I am an expert but I run my truck in 4wd about half of the time and I would run it all the time but get tired of the jerking and binding when you turn. But from what I have learned shift on the fly means make sure you are going straight and let off the gas or coast at a steady speed.

 

It really doesn't matter what I prove on my own, the dealer needs to prove it to themselves before they will do anything about it. Looking at my Powertrain warranty and extended warranty, the part may not be covered anyways. I have recently noticed that the transfer case stays engaged even after coming to complete stops, so long as I drive in a straight line (no cornering). It doesn't always do this, but I never noticed it before because of all the city driving, there are frequent turns.

 

40 years ago I was told at a local 4wd shop that the front ring gear has one less tooth than the rear ring gear on a 4wd. This is designed this way because for a 4wd to operate correctly the front wheels MUST pull, not be pushed by the rear end. So if this is true the front axle ratio is minutely different than the rear ratio, therefore, the ratios being different the drivetrain is in a constant "bind" and I think this may be part of the 4wd being trickey to disengage.

Oldstuff

 

30-40 years ago that was true. the dana front ends were not available with the same tooth counts as the corporate rears.

so you would end up with a 3.54/3.55 and 4.10/4.11 (front/rear). this was close enough, but not necessarily by design. it was just the nature of the beast and it was considered acceptable to have up to a 3% difference in gear ratio front/back.

AFAIK, this is no longer true. if it were my AWD transfer case would have been shot long ago. i think the dana and corporate designs have finally agreed that it is best to use the same tooth counts.

i could be wrong though, i have not had either one apart to count teeth.

 

Having a similar problem. In 2WD and at slow speeds, I hear the front end "whirring". Switching to AWD makes the whirring louder momentarily. There is no "click" as if the 4HI is engaging. I think the actuators aren't working properly. I took it to the dealer and they could not "prove" I had a problem and the whirring noise stopped after they drove it. After I got it back, engaging AWD and 4Hi made the "clicking/clunk" noise of the 4Hi engaging and the clunk while switching back to 2WD.

Today it is whirring again and no audible or tactile feel of the 4WD engaging. I guess it has to have a catastrophic failure to get my Ford to approve a warranty repair.

 

The latest on my saga, dealer says it seemed to be working normal. I had them put it on the lift and we confirmed that the wheels stop, but the frt dr shaft and axles do not. Their claim is that since the gears are engaged, they will not release until all load is off. I.E. shifting to neutral or reverse. I am waiting for a call back from their customer satisfaction rep who has engineering knowledge to confirm that. I'm not convinced because of all the feedback from other owners. I believe that they are sincere, because they don't make money unless they do repairs.