'02 XLT 4x4 whine

[Quadcylla]

I just moved back home to Colorado after spending the last 5 years in Texas. My 4 wheel drive went out 5 years ago, but living in TX, I didn't need it so i left it alone. When I got back, I replaced the control module (behind the glovebox) and I now have 4x4 Hi, but the 4x4 Low just blinks and won't engage. Any ideas?
Also, my 4x4 Hi whines like a banshee. I don't use it on dry pavement, I only drive at low speeds below 40 mph... any ideas on this one too?

Thanks!

 

[detroitrw21]

to get it into 4Low you need to be in Neutral, and pushing the brake. As for the whine I know the diffs make a noise on the '02, but I can't be much help on what to do to help. I think if you do some searching on here you can find some things to try, or maybe someone more knowledgeable can pipe in.

 

[Quadcylla]

Yeah. I had it in neutral and the brake pressed.
*NEW DEVELOPMENT!*
Just got home from a drive up in the mountains (no 4x4, roads weren't bad) and shut the truck off and I'm dropping gear oil from the transfer case like no one's business! Whatever the cause of my 4 Low not engaging was bad enough to blow a seal on the transfer case!
So, my new question is - How difficult is it to replace a transfer case on an '02 'Sploder?

 

[Quadcylla]

*Another New Development*
The boot from the front right wheel (inner tie rod boot) is blown and shooting grease everywhere. But I have a grease/tranny fluid smelling substance coming from somewhere. I've been under this thing for two hours and can't find the source. Anyone have this issue? All this started when I put in the new 4x4 Control Module and got 4 High (still no 4 Low). Somethings up, just don't know what yet.

 

[lunchfist]

Sorry i can't be of more help.. i'm having a similar issue, just bought my explorer a few weeks ago, and it whines in 4hi (not quite like a banshee, but noticeable) from about 2000-2500rpm. Haven't gone over 25mph with 4hi, and 4lo works just fine... Haven't been under it yet to see if i'm leaking any fluids/ or have damaged boots... hasn't given me any drivability issues yet though... just a little noisy.