Thanks for using Just Answer, there is a TSB (Technical Service Bulletin) from Ford in regards XXXXX XXXXX situation, hope this helps you out.
Click Here for TSB
Yes that is correct, your vehicle does apply.
ok shawn thanks very much for your help........ I would like to let you know how i made out is that possible?
hey shawn whats good its jason, i worked on truck today and made some progress. it was the the front wheel bearings that was making the noise. left side completely shot and the abs sensor was cooked , thus sending a crazy signal to all the lights. 4x4 is not engaging by itself any more however when truck is put into four wheel drive and is turned sharply there is some pretty disturbing clunks that can be heard. ???? any ideas......... thanks again for all you help
Ford site is down right now but as soon as things pop up I'll get back to you as soon as possible.
There is another TSB from Ford as well in regards XXXXX XXXXX situation also double check the half shafts for any spline damage which may also be making the noise.
The best way to service a differential is to remove the cover, that way you can inspect the gears as well as remove all the debris, however if you can get a tube in there and suck it all out, that would be easier.