Hi all,

Bought a 03 Screw 5.4L, AT, 4x4 manual shift. The 4x4 worked when I test drove it then didn't work when I got home and was stuck in my driveway. Over the past 2 months it has shifted into 4x4 roughly 4-5 times out of many tries. The fuses are good, the dash lights come on properly, the axle to the T-case locks up properly, the vacuum to the CAT is good and the fork on the t-case moves on it's own as far as I can move it with my hand. And still most of the time it won't lock in except for every once in a while when I tried it it would lock(almost never when I needed it). Also the AT tends to jolt into gear both R and D then shifts smoothly between gears. Related?

I determine that it has locked in when the front wheels bind on a sharp turn. It sounds/feels the same when it says I'm in 4x4 and I'm not as it does when it is working right. The only difference is when it's actually working the front wheels bind on a sharp turn.

The first time it locked up right I was stuck in my sloped driveway of ice and it took 15 min of back and forth till it finally kicked into 4lo.
Once when in a parking lot going strait and 10MPH. It locked in 4hi and wouldn't unlock until I stopped and reversed a smidgen.
Another time it locked in 4hi while going down a road strait about 25mph then I took it out and put it back in and it wouldn't go in again.
Another time I was stuck on a snow drift and I shifted it into 4lo, backed up and it worked fine getting me out and I went back to 2hi.

What is left to check?

 

You may want to heck the vacuum and make sure it not sticking with mud or something. only thing I can think of

 

On the fork on the c.a.d. there is nylon things that ride on the sleeve inside the dif. On mine those broke off. Everything else worked fine. It had me stumped for a while let me tell you. It might be a good place to start.

 

i have a 97 150 same problum checked the drive shaft and i drove the truck in 4 hi for a day and it started working no problums sence hit a few bumps too

 

Thanks Scooba, I'll have to look into those "nylon things" on the CAD fork. Do I have to take the differential apart to find them?

 

Maybe I'll try driving it in 4hi on Wed. thanks 97 Ford F-150.

 

The truck is clean, no mud. The vacuum works perfect and moves the fork just like it shood. Thanks though eliminator

 

I played with 4hi yesterday and got it to engage 6 times out of 9. The times it didn't engage was because I had to get on the road so I gave up before it engaged. Each time it engaged it took between 10sec to a min before it kicked in and it seemed that it engaged most often when in a half turn to the left. Everytime but one I had to either put the trans in reverse, back up and go in D again before it would go back to 2hi. The other time I put it in N and reved the engine then put it back in D with it sucessfully going back to 2hi.
It's strange though that it's first time engaging was over a span of 70 yards @ 12mph level going strait then engaged on the first turn left. After getting back to 2hi I put it in 4hi, took a right turn, went 1/2mi @30mph, took a second right turn, took a left turn and went 50yrd, and took a second left turn before it kicked in. The other two times it kicked in took about 30 second of going 15mph and swerving back and forth. It would always engage when halfway in a left turn and was not predictable.
And the trans jumping into gear is only at cold startup. Never mind that.
Thank you

 

Any idea's as to why 4x4 only works sometimes?

I couldn't get it to engage when on the jacks.

Should I take my t-case appart?

 

Basically you pull the pass. front tire off and start pulling the cv shaft and everything else till you get to the diaphram were the shift fork it located. Its just to the right of the diff if i remember. Its a lot of nuts and bolts but its not to bad. But you just pull the fork out of there and you will see what i mean by nylon things on the fork. Took me about 3 hours or so.

 

You were right skooba,

I talked to a guy in my church that works at the Ford parts desk. He said those nylon things break or get loose and it won't engage right. Also said that turning left helps the syncro things to get in place, so they sell the whole shifting fork unit for $125 +tax.
I guess I'll see what happens when I get some time that I don't need to truck for a bit.

 

Victory!
Got the front end put back together and it engages like it's suppost to. The whole process wasn't too bad once I figured out I didn't have to take appart everything and once I got the bolts and axle tube unstuck.
Started by taking off the front passanger tire, moved the brake calaper(though you might not have to do that) unhooked the tierod end and the sway bar. Useing a long bar between the lug studs and hitting the ground I broke free the 6 bolts to seperate the drive axle from the axle tube and move the drive axle out of the way. I then disconnected the vacuum pump piston from the shift fork lever. Never did get that pump free from the ear, just left it there and worked around it. Removed 3 of the 4 bolts connecting axle tube to differential. The 4th bolt is behind the vacuum pump so I got it half way out. Then disconnected the axle tube bushing support and the differential front support using a jack to support the differential and lower the assembly enough to pull the axle tube out some and finish getting the 4th bolt out. Ended up useing an old wood chissel to get the axle tube seperated from the differential. Took a drill bit and drilled though the pin holding the shift fork in place then pulled the shift fork lever out and replaced the old shift fork with the new one in the kit as well as a little o-ring on the shift fork lever then hammered in the new pin supplied with the part kit. It would be easier to install the shaft syncro-thing into the shift fork before pinning the fork in place. Then slide the axle tube assembly back in, with help because it's hard to line everything up and get that 4th bolt back in yourself. The rest is just put everything back nice and tight. I took some pics I'll have to put up latter, Got to go

 

I have very similar problem with my truck. So the shift fork is a common problem.