Transfer Case/Speed Sensors

[Pack]

Anyone out there ever replace the speed sensors on the transfer case to fix the front end from engaging on dry pavement? Anyone have any experience with the control trac system engaging on dry pavement, making a nasty noise. I would like to fix this problem ASAP, so that I dont wear the front drivetrain parts. Any help is appreciated.

 

[Robert]

I have removed both of mine per a suggestion by a Ford mechanic to fix a moaning noise I was hearing. The moaning turned out to be my brake caliper slides needing lubed. I'm glad I didn't pay the Tech $130 to clean my speed sensors like he suggested.

Anyway, they are very easy to remove. You might as well do a transfercase fluid replacment since if I remember correctly when you remove the speed sensors, you'll loose some fluid anyway. The rear speed sensor comes out very easily. To get to the front one, you have to remove the transfercase shift solenoid. Once it is removed the front sensor comes out as easily as the rear. When I put my shift solenoid back on, I must not have gotten the worm gear back to its original location since the next few times switching to low produced very nasty grinding sounds. I think there might be a write up in the FAQ section regarding the shift solenoid, otherwise someone who has removed it and reinstalled it without the problems I ran into might be able to give you some pointers.

 

[Pack]

Thanks, anyone with same problem?

Does it sound like the fix to my problem is to replace the sensors?
Thanks.

 

[Robert]

Usually when the front wheels engage on dry pavement when they shouldn't it is due to a bad speed sensor. Usually when one goes bad, your 4x4 and Low lights should light but if I remember right not everyone has gotten the flashing lights. There is also a TSB regarding harsh engagement of the control trac. It calls for reprogramming the GEM to provide a softer engagement. The GEM is the computer box in the jack compartment that controls the control trac, power windows, theft deterent system, etc. If the speed sensors do not fix the problem, I have heard of a bad GEM causing it. Last resort would be a new transfer case. I don't know what a speed sensor costs, but it shouldn't be very high. Since it has been two years since I had mine out, I can't remember for sure but I don't think you loose much fluid when you remove them. Look at your tranfer case and see if they are above or below the fill hole to find out how much you will loose. If it were my dime, I would buy one sensor and put it in place of the rear one. If that didn't fix it (and it probably won't since it will likely turn out to be the front one from the symptoms you described) I would then take the one removed from the rear and put it in the front. The reason I would do it in this order is that the rear one only takes a couple of minutes to remove and replace. Refill any fluid that you loose in the process. The front one will require removing the transfer case shift solenoid. I would only want to remove the solenoid if it was absolutely necessary. If you started with the front sensor and it turns out to be the rear sensor you will kick yourself for removing the solenoid when you didn't have to.

Reinstalling the solenoid probably shouldn't have been as hard as I ran into but I didn't have any procedures for putting it back on. I just remember that the first several times after I put mine back on having major problems getting into and out of Low. The problems have worked themselves out and I haven't had any problems with the 4x4 in almost two years now. I would say yeah, try the sensor.