4X4 problem ?

[Umaxman]

Hi Guys
I have a 2000 Ford f150 4x4, V6 auto. 75000 klms on it.
Problem is when I put it in four wheel drive the light comes on but it doesn't lock the front end in, same if I try it in low range...light comes on and the truck is slow like it is in four low but the front is not locked in? Any ideas as to where to or what I should be looking?
It did this a couple times before but if I put it back in 2wd and then back in four high or low it would work but I tried it the other day and nothing?
Oh also have an exhaust leak up front, not good I am told as the front pipe is very expensive?

[Lilbigtrk]

do you have manual locking hiubs or automadic?
manual's you obv have to get out and lock them
auto's could be broken and there fore wont lock.

i have auto's and broke 2 of them alonge with a u joint.

to find out if there broke or not take them off and and look if the inside gear that is deep like at the bottem when you look in it. if you can pull that up its broken
thats all i can think of.

[LayinHp]

are these trucks not vacum fed for the front 4x4 ? if so you may have a vacum leak so its not engageing the 4wheeldrive

[fordfan22]

i had a similar problem and all it was for me was transfer case was unplugged. so rear tires go like they should, the "4x4" light comes on, but front tires don't do shit.

[shelbyx1]

the 97-03 f150 was notorios for the shift fork in front diff braking(just move the lever on diff by hand and see if it locks),also the diff lock vacc lines behind the batt box rot out.:)

[Umaxman]

Ok so this weekend I am looking for vacuum leaks behind the battery box, unplugged transfer case and broken shift fork on front diff. Well I hope it is something simple but thats not the way My luck usaully goes :)
Also do the hubs come off fairly easy?
Thanks for the replies..its a place to start :)

[Umaxman]

Ok I checked the vacuum lines and they look good and the vacuum assit shift (not sure of the real name ) seems to be moving in and out , not very far but it moves. How would I check the shift forks..just undo the pin and try to shift it by hand?
The front hubs are next :( does anyone have a diagram or a picture of how they come apart:icon_rolleyes: . Is there a way to check the hubs by jacking up the front end with the transfer case in gear(truck off) and turn the wheels by hand and if the hub is not ingaging or is broke one should spin free? Probably a stupid question but I had to ask :icon_razz:

Edit: the plugs all seem to be connected good

[shelbyx1]

the front hubs on the 97-03 aresplined to the axles full time to check the front difflock lift front tires off ground(support with stands for safety)turn front wheels while moving shift lever on diff.

[Umaxman]

Thats what I kind of thought when I looked at them, I don't see that one of those would be stripped or my wheel nut cover would have metal filings in it or I would hear something ?
I think I will unhook the vac. shift thingy and try shifting it by hand and see what happens ..
Thanks

[Umaxman]

Ok just to update the post..I moved the diff. lock lever by hand and the wheels would spin free and when I shifted it the other way the wheels locked up. I put a little spray on it and worked it back and forth a bit and now it works fine, the only problem is I don't see how it would have gotten sticky because it is used on a regular bases :icon_question:
May the vacuum line does have a small leak and with it being stiff just wouldn't work it :icon_confused: But it works now and I am glad it didn't cost me anything :icon_biggrin:
Now on to the exhaust leak...anyone know of a cheap exhaust system for me( well not cheap system but a cheap place to buy from maybe)
Thank you all for the help :):H)