My truck won't engage in 4WD. 98 F150 w/electronic SOTF. The light is on on the dash and I can hear the transfer case moving, but no four wheel. It has hung-up on me before. Is there any quick fix for this? I have already had the electric motor replaced once. I've been playing with this for a few days. So far I have: tried engaging in drive and reverse, tapped on the transfer case with a rubber mallet, shifted into low range (still won't go into 4WD), and tried different rolling sppeds. Any advice appreciated.

 

I'm having similar problems, my truck will go into 4 high no problem but won't go into 4 low. I took it into the shop, initial estimate to diagnose was $80. They called and said they spent three hours trying to diagnose and couldn't find problem. Next step they wanted to replace some module under the dash but they wanted 350 in labor and depending on module either 120 or 220 for the part. I told them not to bother. They also said it might be a short or ground problem cause they checked the electric motor and that works fine. I'm going to tear the dash apart and find the module and see if that is the problem. I'll keep you guys posted, good luck with your problem.


eidaj

 

I have a similar problem on a 00' Expy, the A4WD worked once or twice and that was it.When I brought it to the dealer ,they said they would have to get it to engage(they wanted to beat on it on snow or ice)I told them not to worry about because 4WD works when I turn the switch.From what I read on other post ,there is something called a GEM module,this is supposed to control a variety of functions.Good luck .

 

My truck has the same problem. I think it is the hydraulic actuator that engages the front differential. I had a mechanic troubleshoot the problem a few days ago and he was hammering on the actuator with a rubber mallet trying to get it to work.

If this thing is shot, the transfer case is working OK and the front driveshaft is turning, but the actuator fails to lock the shaft to the front axles through the diff.

I don't think it any big deal to replace, parts would be the biggest expense.

If a quick fix is required, I would try beating on it with a hammer and see if it jars something loose. If nothing else, it is always fun wailing away on some broken mechanical thing just for personal satisfaction!!!

 

Mashie Banks, this sounds like exactly what is happening with my truck. I can hear and feel the transfer case engage, and when I slowly pull to a stop sometimes I get a clicking noise from the front diff that sounds like some gear is not throwing out all the way to engage. I don't know if that is the actual way the front engages, but that is what it sounds like. Any indication on cost of replacing that actuator?

 

A vacuum motor mounted above front diff operates the right front axle.

 

Yeah, I talked to a guy last night who had this problem on a 2000 Jimmy. He said the same thing, vacume motor. He said his cost $6 and took 1/2 to replace. I looked it up in the Haynes manual, it doesn't look hard on the Ford either. Two vacume line and an e-clip. I'll start there as I'm about 90% sure this is the problem. This motor has blown before on me, but it was under warranty and I didn't look hard at the repair invoice.

 

I have the same problem and have had it every fall since the truck was new. First few were covered under warranty. Second few I had to purchase on my own. I think the price of the vacuum motor was around 15.00. This year, howerver, I dindn't purchase a new motor, I just took the vacuum lines off and put a few drops of oil in the motor. Then worked the motor back and forth a few times by hand and since then no problem. Hope this helps.

 

A good fix for most of your problems would be to install some manual hubs. That is if they make them for our trucks. They are much more reliable if your electronics fail.