i am new to this board, but love everything i have seen so far! ok...now for the problem. i have a 1998 f150 supercab, 5.4L automatic, with the 4wd shifter on the floor. up to now, the 4wd has worked just fine. however, just last week when the snow hit i found a problem. i engaged the 4wd when leaving home, made it up the driveway and out the road (backroad) with no problem. once i started to get on the onramp to the interstate, i shifted out of 4wd, and was doing about 15 mph. i noticed as soon as i sped up that something was different. i could still feel that the 4wd was engaged. the light was off and the shifter was in 2H. i drove about 5 miles doing about 55-60, slowed down and tried to shift back in and out again. no luck. i finally had to pull over, stop, and put the trans back into park before the 4wd would disengage. what would be some likely causes and solutions for this? i dont use the 4wd out on a dry road, except on some straight stretchs while doing about 20mph just to get things moving.

 

It would seem that your system was in a bind. A part time 4x4 system by nature needs the wheels to slip for it to function properly. Or in a perfect world each wheel must turn at exactly the same speed. The latter being impossible we need the slipping. When you run 4x4 on a dry surface the wheels can not slip so the system binds. Take your truck out to a dirt road or a snow covered road and use the 4x4 system. Engage it and run for a few 100 feet and disengage 4x4. Do this a few times. If after this it still sticks get back to me.

Regards

Jean Marc Chartier

 

i had already tried this on the couple of days when it snowed here. i would put the truck in 4wd when leaving the house. my driveway was still snow covered with very slick spots, as was the road i drove on for about a mile. snow covered and slick. once i made it to the end of the road, which was about a 100 yard downward slope, i shifted back into 2h since the snow had been cleared in that section. when i took off from the stop, the 4wd was still engaged even though i had shifted out. i had to stop, put the truck in park, then when i started in drive again the 4wd had disengaged. another thing i tried was to back up the driveway. in 2wd i wouldnt even make it up 1/4 of the way. i shifted into 4wd, it engaged and make it to the top of the hill which was about 40 yards. i shifted out of 4wd, let the truck come back down the hill out of 4wd, then tried to back up again when it was shifted out. the 4wd was still in. it only will disengage when i put it in park.

 

Are the 4x4 lights out when you shift out of 4x4 and it remains stuck in 4x4?

JMC

 

I just reread your post and you did mention that the lights were out. One thing to try before opening the T-case is to adjust the external linkage. If by chance it is just out enough to turn off the switch but not completely disengage 4x4 and putting it in park moves the tranny/t-case enough to jerk it loose....
If this doesn't work I can only conclude that there is an internal shift fork problem with the T-case. Because the shift lever is connected to a linkage that is connected to the switch that turns on and off the 4x4 lights and they work properly according the the lever position, and the same levers are connected to an internal shift fork, then it has to be an internal problem.

Regards

JMC

 

I once had this similar problem on my 97 4x4. I read somewhere in the Owner's Manual about putting it in park or neutral, and revving it up so it will disengage into 2H. It worked. But I took the truck in for service and had an actuator or something replaced under warranty. I think it has to do with vacuum due to having the engine rev up.

Warren.

 

i dont know about ford 4x4's but in landrovers they recommended driving in reverse for about 25 feet and thats supposed to get it back into 2wd. Might be worth a shot.

 

At the time, I tried putting it in Reverse and rolling it back too, but it didn't work for me. Just revving it out in Park/neutral did it for me. The 4WD light finally went out. I was in Baja Mexico about a hundred miles away from San Diego when this happened. Luckily it finally disengaged back to 2H.

 

Here in lies the problem. We are told that it remains in 4x4 even if the lights go out. This means that the front axle is still locked and so is the T-case.

When the lever is pushed forward into the 2Hi position this should mechanically disengage the front drive shaft. Appearantly this is not happening. When that lever is pushed, it opens a closed switch that sends a signal to the gem that then sends a signal to the front axle disconnect solenoid that allows vacuum to travel to the front axle disconnect motor to disengage the front axle. I do not believe that if the front axle disconnect motor jams that it will keep the T-case engaged.

JMC

 

Are you absolutely sure it is still in 4 wheel drive when the light goes out? In my truck when I shift from 4 hi to 2hi the light goes out right away but I still have the four wheel drive noise so to speak and just by leaving off on the gas for a second all is back to normal. One other thing my shift linkage was really getting hard to move and I crawled under the truck and sprayed all the 4 wheel drive linkage with WD-40, works much better now. Does this help any?

 

well, backing up doesnt seem to help any. i backed up after shifting out for about 75 yards with no luck. i have tried just putting into neutral while i was still moving after i had shifted out, but it still stayed in 4wd.

i am very sure it stays in 4wd after i shift out. since it snowed, i tried again this morning. i shifted in 4wd, and i could hear it engage slightly, and it was locked. while driving out the road, which was really slick this morning, i shifted back out, slowed down for about 20 ft, then i gave the truck some gas. i didnt fishtail at all. then i stopped the truck, put her into park, back into drive, and took out. as soon as i touched the gas, it fishtailed right off the bat.

 

I think what you are experiencing is a result of the vacuum lines getting wet and damp, then the cold weather we are having here in "Almost Heaven" causes these lines to freeze and that causes sluggish solenoid operation. I bet when it warms up the truck will be just fine.