I own a 2003 Ford F150 4X4 supercab Lariat edition. I have seen another post like this one on here so I know I am not the only one now who has had this problem. My truck has shift on the fly 4X4 low and high range. The truck will shift into both just fine. I go fishing at the coast out on the sand alot and down in fields where I need a 4X4 truck. As soon as the 4X4 comes under a load like turning or slipping and grapping in the mud. It pops out of 4 wheel drive and want go back in until I get the truck back on hard pavement and get going down the road. When the 4X4 pops out it makes a loud bang and then pops straight out. The 4X4 lights are still lite up both on the shift on the fly switch and in the console area. This vehical has been to 4 dealerships in North Carolina and some of those 2-3 times and they all tell me the same thing they cannot duplicate the problem in their shop. Well duh it happens in sand and mud. Please help!! I paid $40,000 for a vehical that since it came from the factory has really been a $35,000 2X4 vehical. Any help would greatly be apricated.

 

That will be a tough one to duplicate at the dealership as no intelligent service manager is going to encourage his technician to duplicate those conditions with a customer's vehicle. The easiest thing to do may be to troubleshoot it on your own, but it'll take some preparedness on your part... you'll need a jack and pair of stands, and maybe a big pair of channel locks (large enough to grab the front driveshaft with). When it goes bang, leave the **** in whatever position it was in, stop, jack the front end up, and put it on stands. (May want to limp it back to a parking lot first, or at least put the stands on stable plywood footings) Once the front wheels are in the air, grab the front driveshaft with the pliers and see if it'll turn. It should not. If it does, you've got a transfer case failure of some sort (and we can go from there, but I doubt that's the case). Assuming it does not turn, give one front wheel a spin. If the center axle disconnect is engaged as it should be, the other wheel will turn the opposite direction, and the front driveshaft should still be stationary. I suspect the center axle disconnect is failing to stay engaged (vacuum or solenoid issues) but without being able to troubleshoot it when it's doing it, it'll be a tough one to troubleshoot.

Another option, if it's not too far, would be to let it fail, then limp it to the closest dealership with the understanding that the tech will need to drive it right in and take a look at it. An understanding service manager should be able to make that happen, but you'll need to work with them as it'll be a special case, and not their normal M.O.

 

Ok I did what you asked and the drive shaft does stay locked in when it pops out of four wheel drive. The wheels at first turned in opposite directions and then when it popped out they spun freely. So I guess it is in the front end or the vacuum or solenoids as you said. What do I do now.

 

All righty-then.... That means the t-case is safe. Now, when it's doign that, you'll need to check the vacuum lines. On the passenger side firewall under the hood, there are two electrically actuated vacuum solenoids. The GEM grounds one or the other, never both at the same time. What commonly happens is that the disengage solenoid sticks, so when the engage solenoid comes on, you end up with vacuum on both sides of the actuator in the center-axle disconnect, and it fails to engage. It's possible that yours isn't fully disconnecting the disengage side when it should. You should be able to remove the two lines and check for vacuum on both of those solenoids (one or the other, never both simultaneously) as you switch from 2wd to 4wd and back. A crack in the vacuum line, or a bad Center-Axle Disconnect could cause the same issues. It's a little tough to troubleshoot remotely, but that's where I'd start.

So.... start with the vacuum solenoids. If those seem to be working properly, check the other end of the lines where they connect to the disconnect. (If the vacuum is good on both ends, there is no need to trace the lines to look for leaks, but it's not a bad idea) If the vacuum system works, you may need to disassemble/replace the CAD and/or check the axle for some internal damage to the unit. That'd be even tougher to troubleshoot remotely.

A third (and final, and costly, and less convenient) option would be to go with a unit from 4x4posi-lok. It provides manual engagement of the CAD via a push-pull cable. Far more reliable, but a moderately complicated install.

Good luck!

-Joe

 

Ok I checked all hoses and no leaks. I checked the vacuum solenoids and they are working as well. I cant tell though if they are fully working or not as I dont know how to test them other than felling the vacuum. Is there anything else that it could be. What are the solenoids actually pulling in. Is it possible that what ever they are pulling in is not going in fully. I am leaving for the coast in like 3 weeks for 2 weeks and still dont have a 4 wheel drive truck. What would be your next move if it was you. Thanks again for all your help.

 

That's about the best way. If you had a vacuum gauge, you should see both sides being equal, and I'm sure there's a spec, but it shouldn't take much to actuate the Center Axle Disconnect. I assume you checked for vacuum at the actuator too? Also, you should not have had vacuum on BOTH solenoids at the same time, correct?

That leaves either a problem with the CAD itself, of the differential guts, and neither one is a cheap or simple fix. I've never played with the actuator manually, but I've been told that you can pull the boot back and inspect the shaft where it slides in and out of the actuator. JMC is a bit more familiar with those guts than I am, so it would be worth an e-mail to ask. Tell that Canuck I sent you, but make sure you type slowly and use small words LOL!

The vacuum actuates the center-axle disconnect on the front axle. Basically, in 2wd, it breaks the passenger side axle shaft between the diff and the halfshaft. That allows the differential carrier and front driveshaft to stop turning when in 2wd. The spider gears in the front diff are still driven by the driver's side halfshaft, but as long as the fluid level is good, they don't pose much of a drag on the system. But I digress...

The center-axle disconnect has a vacuum diaphragm and actuator that slides a collar over the two halves of the axle shaft. I suspect that either the actuator is sticking (in which case it probably wouldn't engage in the first place) or it may not be fully engaging (they sometimes get rusty or gummy and only engage part-way). It's also possible that the fork itself is bent or broken, or the nylon feet that engage the collar have worn enough to allow the gear to disengage under extreme loads. Without taking it apart, I have no idea.

I would do one of two things: Take it to a good driveline shop and have them drop the front axle to see what's going on, or hope a dealership doesn't rake me over the coals on the diagnosis and repair. The only other option would be to disassemble the CAD (If it can be done without dropping the axle... I don't know offhand). If you're dropping the axle, I'd pop the cover and see what you can see in the front axle too. It's possible a chipped spider gear could cause the problem... if it gets to one particular gear alignment and pops out, that could do it, I suppose, but there's no way to know without removing the cover.

(My million dollar idea: a portable auto X-ray/fluoroscope. You'd be amazed at what you can see without opening up a part! We have one at work and the info you can get is truly amazing!

 

My 4X4 as you can read below was popping out of four wheel drive in a bind in Hi and Low range. I just got it back from the Dealer and come to find out it had a bent shift fork. After $725 it is like brand new and works like a champ. Thought I would share. Thanks for all the great help guys. Joe Beeker

 

[QUOTE=GIJoeCam] You should be able to remove the two lines and check for vacuum on both of those solenoids (one or the other, never both simultaneously) as you switch from 2wd to 4wd and back.

I am having trouble engaging my 4x4 as well. When I removed the vacuum lines from the two solenoids I was getting vacuum from both sides simultaneously. What could this mean?

 

Hi folks,

I experienced the most terrifying symptom of this last Saturday. It was snowing, roads were slick and I had engaged 4x4 high. I was climbing the Eisenhower tunnel approach on I-70 in very heavy traffic when the shift fork inadvertently disengaged 4x4 and i was suddenly with power to only the 2 rear wheels. After fishtailing and nearly sliding into the guardrail and other cars/trucks/big rigs, I was able to regain control and avoid an accident.

I took the vehicle into the Ford dealer today and was informed that the "shift fork" is the culprit. My understanding from reading this forum is that Ford has a re-engineered/upgraded part that supersedes the original parts. This in my opinion shows that Ford has acknowledged a problem with this part. My experience on Saturday also leads me to believe that this is a very serious safety issue.

After being informed that the repairs would be ~$620, I called Ford to see if they would be willing to help out. They told me that they would not, there is no safety problem in their opinion and because the vehicle is beyond the waranty in both time and miles, the repairs are on me. I called back a second time after doing some research, and advised them of the fact that an accident could have happened because of this issue and that Ford themselves have "admitted" to there being a problem with the part by manufacturing replacement parts of a different design and material. Still no luck in getting them to provide any assistance. They did advise me that I could open a complaint with the NTSB vehicle safety office.

Their number is 1-888-327-4236. They will review my case and assign an investigator. If probable cause for a recall is found, one will be issued and Ford will be compelled to replace this part across the board.

I would highly recommend that anyone who has had this problem, call Ford @ 800-392-3673 and lodge the same complaint as I. Also, take the 10 minutes or so and lodge a complaint with the NTSB.

This is a safety issue and Ford should be held accountable.

Thanks,

Brian

 

I bought a used 2003 F-150 OFF Road earlier this year (April-my first 4X4), for only one reason - to pull out our boat(our lake has no access/no ramp). We didn't have any problem putting it in on Memmorial day. Last week I decided to move a stump in our back yard that I had cut in the spring. I shifted it to 4 wheel low(put in nuetral/brake on, and it shifted/small clunks, and 4X4 Low showed up in the dash - this has the dash shift). For my surprise, only the rear axle was working. Talked to friends at work, and they mentioned that I have to move it approx 20 ft to get it to engage - OK. That night I tried again no success. Went to the local auto parts store, and got a manual for this vehicle. Took about 15 minutes to figure out that it was internal axle problem - vacuum was working properly, and the shift motor was moving the shift arm. Dropped it off at my local Ford dealer - 1/2 hour later - yes sir you have a bad fork, and need a new fork/sleeve. Go figure. I had told them that it was in the axle. My manual did not get into detail of axle tear down/setup, or I would have done it myself.
So I'm on the bandwagon to call Ford, and anyone else to get this taken care of. It sounds to me that there was manufacturing problem(yes they also told me there is a revised fork!). By the way the truck had only 46500 miles when I bought it - now 48500(an elderly gentlement who used it for pulling his fishing boat). Ford appearently have brought thier rate down - told me $485. I'm sure tax hasen't been added. Yes I'm very disappointed with this. I have a few more years before retirement, and have owned Ford trucks all my life, and never had a major problem(some new/some used). As far as I know, this truck was never abused.
So if there are others that have this problem, please let them know about it. Maybe, just maybe we can have this a recall problem. Thanks, mrd

 

Would you post the part number for the revised shift fork?

Thanks

Jean Marc Chartier

 

I'm on vacation, and will post in about a week - sorry

 

I'm back, sorry for the delay! Here is the revised part # for the fork kit - F75Z-3N139-KT FORK, I hope this helps. After inspecting the old parts, the fork actually looked ok, except for some small rubing marks where it had been trying to shift back, and forth without the nylon/plastic guides. All I know at this time it works fine - because it pulled my boat out ok. I guess if you know you are going to need your 4X4 working, take it on a gravel/loose dirt, and shift it, and turn it one way or the other, and see if the rear inside wheel is slipping(my only way of knowing for sure without hurting anything). The mechanic said with this update, I would probably never have a problem agiain. Lets hope not! Thats all, mrd

 

Man, I read through these threads from time to time but had forgotten I had an account on here

I have a 2001 F-150, it's having similar problems that the OP's had. Mine will pop in and out of gear, I have a good feeling that the CAD is disconnecting on its own causing the trouble. As a matter of fact, even with the 4x4 engaged the vehicle was fishtailing as if there was only partial power to the front axle at both the driver and passenger sides. I had a friend look at the half shaft, he can tell that it's been tampered with due to the sealant coming off the differential not being from the factory.... I couldn't tell the difference. According to a shop that looked at it they couldn't find any trouble with the drivetrain but i'm not convinced that it isn't broken. I would much rather have a working 4x4 vehicle, being stationed in Alaska makes it difficult to get from point A to point B from time to time.

Any help would be appreceiated, in the meantime i'm going to investigate the shift forks on mine.

 

I am troubleshooting the same issue (I think). 2003 F150 4x4 does not work. Raised the front and can turn passenger side tire and shaft turns all the way back to the transfer case. Driver side wheel does the same thing. Is it normal to have the front drive train locked in 100% of the time? Ford dealer wanted to replace the shift motor
(Part #YL32 7G360A $220.00 + labor) but I can hear it working and feel it link up with the 5.4 off. Anyone have a diagram of the Shift fork or the disengage solenoids?

Thank you for any ideas.