My 97 F150 4X4 will occasionally engage into 4X4 by itself. It has the manual 4X4 selector on the floor. While driving the truck in 2Hi the 4X4 light comes on and a grinding noise starts. While slowing to a stop the gears grind hard and then it clunks into 4X4 at a complete stop. The selector is still in 2Hi and hasn't moved. To get it out of 4X4 I have to pull the selector into 4Hi and then push it back into 2Hi. The light goes off and then it's ok for a while. It seems to happen more in cold weather. Anyone else hear of this? or know how to fix it?

 

I have the same configuration on my truck, and have never had that problem, or I have never heard of it happening either. There must be a short somewhere in the wiring to make that happen, might want to start looking at the wires going to the transfer case and see if there is something that is cut, or knicked....Never know. Just an idea of where to start before bring it to a shop to be looked at.

 

I have that VERY SAME PROBLEM !!!!!!!!!
Drivers me nutt's!!!
I have a 97 4.6L F150 4x4 ExtraCab. I had the rear end & transmission rebuilt at Sunrise Ford in North Hollywood CA. When I got my truck back after 60-80 miles of Highway driving & hard braking it happened exactly how you discribed it. What makes me even more mad is that this never happend until after I got my truck back from Sunrise Ford. So I took it back to Sunrise & they replaced a electric clutch relay switch in the dash (heard clicks when the 4x4 light comes on) & replaced the electricomagnetic clutch in the trasfer case. As I read when Shifting from 2WD to 4WD High an electromagnetic cluth inside the Borge Warner 4x4 Transfer case drings the front driveline up to engage. The 4WD light luminates and the electromagnetic clutch energizes. This system is called the "MSOF" system or the MECHANICAL SHIFT ON THE FLY system. Sad to report however that the truck started to self engage in 4x4 again. I called the TRUCK service Mgr Ron at Sunrise for from the Highway to tell him it's time to bring the Factory tech in on this one. I'm tierd of having to take my truck ing so in thinking if it's an electrical engage system, I can simply cut the + wire that energizes the clutch system and mount a switch on the shift lever that swithes on when the lever is pulled back. Maybe I can use a tiny toggle switch to flick on b4 I engage the 4x4 lever. Anyhow I'll let you know if FORD fixes the problem. The No to Sunrise Ford is (818) 980-9800 ASK for Ron. Tell him you spoke to STEVE about his white F150. He might have some new info on the fix... Good Luck... STEVE

 

BScott2960,

Has the shift linkage been adjusted? It could be ever so slightly off and causing the system to engage after a bounce or bump. It coulds also be a shorted circut or switch that goes off every once and a while. Engaging 4x4 clears it up and fixes it for a while. What ever it is it needs to be looked at.

Regards

Jean Marc Chartier

 

I finally found out what the problem was. It wasn't the gears I heard grinding but auto locking hubs trying to lock by themselves. There is a little sensor on the transfer case with a 2 terminal connector that looks sorta like an oxygen sensor or something. When the linkage in the transfer case moves into the 4x4 position this sensor is suppose to tell the auto locking hubs to lock (the 4x4 light comes on and you hear the relay click). When the problem became more consistent, I unplugged this sensor and the problem went away entirely. I replaced it and now it works fine. The old one had some corrosion on one of the terminals. Ford had a hard time finding this part. It is actually an oil pressor switch (part no. E7TZ 7E440 AA). It cost $26.42 and took 5 minutes to replace, although with all that grinding I wonder how long my hubs will last.