Kevin

this happened to me as well... it ended up being an acuator up by the firewall on the passenger side that engages the front axles

firefightinb

This is my first post and im trying to figure out what to do with mine. I have a 2003 F-150 and just a few days ago 4x4 would not engage and the indicator on dash would not come on. Indicator lights up when truck is first started. 4x4 low range doesn't engage either. Anybody know what it takes to replace the acuator or know how to check it?

keepumturnin

what pin are you refering to? my front diff. will not lockin. the lever on top of the ft. diff. that locks the ft. up seems to easy to move back and fourth, with maybe some binding a ll the way over to the left side position. is there a pin inside that moves a fork that might slide the truck in and out of 4wd? where can i find a breakdown of this ft. diff.. it is a 2003 f150.

TheJMC

1997 to 2004 heritage use a center disconnect front differential. The wheel hubs are splined to the front halfshafts and are locked all the time. Like a front wheel drive car. The front differential uses a splined locking collar that slides over the axle shaft in on the passenger side to lock that side of the differential. The driver side is one piece. When you engage 4x4 a vacuum motor pushes a fork that moves this locking collar over the splines to lock the front axle. Common failures are the shift fork wearing out. The vacuum motor failing. The vacuum lines splitting and leaking. Finally a defective actuator solenoid.

2004 + use an IWE ( Integrated Wheel End ) system. A spring pushes a locking collar over the splines in the front halfshaft to lock the two parts of the halfshafts together. The front differential is permenantly engaged as the IWE eliminates the need to engage / disengage the front axle. The default position for the IWE is engaged. Vacuum us applied to a diaphragm that pulls the collar off the splines. In the event of a vaccuum failure you will still have a locked front hub allowing you to drive out of the muck. Ealier modles of this system had problems allowing water intrusion into the vacuum system. The water could cause problems with the IWE and or the actuator solenoids on the firewall. Common failures are the water problems and or defective solenoids or the IWE itself. As the default mode is engaged, a vacuum leak can cause the IWE to engage or worse partially engage. That causes the splines to grind and destroy the IWE.

EDIT: I found the link that explains Ford's IWE .

jhughes2013

That is a good video. Thanks JMC. This happened to me as well except it was after some four wheeling in wet sand and a pop. Ended up snapping the front right axle shaft. I wasn't putting that much strain on the axle so I'm inclined to think it was a faulty part. I have also not heard of many snapping axles in the new Fords. $150 and a few hand tools later I was back on the road.
During this I thought is was the actuator as well. The hubs are vacuum unlocking. If there was a leak it would lock in 4wd. This is why there is a huge problem with these Fords blowing the hubs at 60mph just because the failure of a $23 vacuum actuator. A possible explanation to your problem is water frozen in the vacuum lines, but if it has warmed up it would be working. Either way water in the lines is bad.

keepumturnin

I get the vacuum lines,vac. actuator comments from everyone I talk too about the ft. end not locking in. But this is not my problem, all that is good. I have something going on inside the ft. houseing.Maybe a shifting shaft, a steel pin in that shaft or a broken fork. The truck is a 2003 F150 with only 80,000 miles and not much use on the 4WD. Guess Iam going to pull apart the ft. end and see what is going on.

TheJMC

Too many different posts concerning different problems to keep track of.

reader585,

How are you making out?

Regards

Jean Marc Chartier

dmeko0

i've got an 06 supercrew. when i put it in 4H or 4L the lights come on the dash and you can hear it engage underneath, however, the fronts don't engage. any ideas on this? the rears go into low range in 4L but the fronts still don't engage.

iamvancleve

I hate to bring up a old thread... But i took my 03 SCREW offroad for the first time and same problem here. high and low range light will come on when i shift to them but no turning in the front.. kindof a SMH moment cuz i opted to NOT buy the warranty when i bought it. If anyone has any ideas pleaseeee let me know. Ill prolly take it to the dealership in a couple days

will0131

1. wlaveryislip@aol.comif u find that that diagram (ACTUATORS FOR 4 DUMMIES) PLEASE LET ME KNOW BILL 06 XLT SUPERCREW