I have a 2004 F 150 4x4 supercab STX with 4.6 , 90,000 miles , And I just realized 4 wheel drive is not working - Never had this issue before

When I shift the shifter on the floor the 4x4 light on the dash will come on but I do not hear it shifting under the truck - Thought maybe the problem could be with the vacume lines that go to the front wheels - I pulled tires off and pulled of the vacume lines- When in 2 wd The lines have constant vacume- when I put it in 4 wd the vacume stops on the lines- I can hear the actuater clicking when it does this but stil the 4x4 dosnt engage and I can hear no clunk - I believe that seems to be operating correctly from what O learned in other threads

If I put the GEAR shifter on the steering collum in nuetral and shift the 4x4 shifter on the floor and play around with moving it through 4 w high , low and nuetral sometimnes I can hear it grindin and eventually think I get it to pop in gear but it never does - All lights on dash work fine but I cant get nothing to engage -

Im guessing that if the vacume lines that go to the wheels are working then its not a problem with the actuator -

Any help would be greatly appreciated - I use this truck consistantly for hunting and my 4 wd is a neccisity

%%PLEASE HELP ME%%

 

Also When I do put it in 4 wheel low and press the accelerator - it seems to lag behind - instead of it jumping in the low gear as normal - when the pedal is pressed it takes at least 3 second before the truck even moves

 

Lift and support the front of the truck so the wheels are off the ground. Key on truck in park shift into 4Hi. Get under the truck and try to turn the front drive shaft. It should not turn. If it does the t-case is not engaging. Look for loose linkage. Try it in 4Lo too.

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I tried this when I was checking vacume lines - Had front jacked and put in 4 wd - even put it in gear - I tried to spin the front tires and they would spin freely - Just dont understand, if the vacume is engaging and disengaging at the front wheeles then I would think system should be working - I can hear the actuator clicking but dont get no thudas it makes when 4 wd is engaged -

 

Spin the front driveshaft (between the transfer case and the front differential) not the wheels.

 

Yes - I just went out and did that (without truck on jacks), when in four wheel drive it will not spin , either in Hi or Lo - but when not in 4 wd it will spin freely - lights all work - the vacume lines are working - I'm thinking it may be a sensor or the automatic locking hubs not engaging -btw - thank you for your help

 

Not to be rude but there is a reason you have to jack up the front wheels. If the front axle is locking the driveshaft cannot turn because the wheels on the ground are keeping it from turning. If the transfer case is not engaging then with the wheels on the ground you will never know.

 

JMC - not rude at all Thank You!! I will do this today - or as soon as I get 2 jacks together - Thank You for ur help!! I think after playing with it yesterday that whweb in 4wd front pass side tire is spinning/got traction but driverside is still goofed - couldn't be absolutly positive cause it was only me, but the mud I was. In showed it was spinning and driversside wasn't - I will do ur suggestion Asap - thanks again

 

Follow my guide here. It will work for the manual shift 4x4 system also.http://www.f150forum.com/f72/how-dia...m-esof-186872/

 

If even one front wheel is spinning, your 4x4 is working as intended. You have an open front differential from the factory. That means all the power goes to the wheel with the least traction. If just one of the IWEs fails to lock a half shaft to a wheel, that half shaft will get all the power in the front and neither wheel will spin. BOTH IWEs have to be working properly to get any.pull from the front.