4WD not working

[DieselFeverDisease]

I tried to use my 4wd for the first time today since I bought the truck a few months ago. I put the truck in neutral, and then tried 4 high and 4 low without any success. My instrument panel showed that I was in 4 hi/low, but my front axles/tires never spun. Front driveshaft is in tact and looks fine from what I can tell. Any suggestions or ideas as to what could be wrong?
I got a new Sun Coast tranny just after I bought the truck, but other than that, nothing has been done to the drive train

[Super Diesel]

Not sure about the 6.4s or not, but you may have a vacuum leak somewhere that is causing the auto-lock hubs to not engage. Does your A/C turn from blowing out the vents to the defrost when you try to switch to 4WD? If so, it's definitely a vacuum leak somewhere in the lines.

[Dave]

Lock the hubs manually see if that works

[DieselFeverDisease]

I didn't have the AC on... I had the windows down, so I'll try that tomorrow. I didn't even think about trying to take the wheel caps off and manually lock them in! I'll also try that

[DieselFeverDisease]

SuperDiesel I forgot to mention that I voted for your rig this month, and it looks awesome! Nice job with everything.

[Super Diesel]

Originally Posted by DieselFeverDisease

SuperDiesel I forgot to mention that I voted for your rig this month, and it looks awesome! Nice job with everything.

Alright!!! Thanks! Yeah, the picture came out pretty good. I wish I could've gotten a bigger chainsaw to hang from the mirror, but it worked out alright. I wanted to wait a little later in the day, but it was pretty freaky where I was, so I didn't want to stick around too long. Haha!

[DieselFeverDisease]

After getting off shift this morning, I went to a near by sand pit and manually locked my hubs... With them locked in, I still had to turn my selector switch in the cab to 4 hi/Lo, but it worked in both settings. I played around testing both hi and Lo multiple times to be sure it was working. After I was done I put my hubs back to the "Auto" position and I was able to get 4 hi and Lo to work from inside the cab. Im not sure what happened, but it seems to be working fine now

[Super Diesel]

Huh, well that's weird. Anyway, glad it's working for you!

Sweet looking rig too by the way. I've always been a fan of the silver SuperDutys.

[DieselFeverDisease]

It's definitely weird! I'm glad it's working, but I hate it when sketchy things happen and then "fix themselves". That always makes me leery and it stays in the back of my mind.
Thanks for the compliment on my rig, Im slowly beginning to get it how I want it but I still have Sooooo much to do! Next on the list is a 4.5" or 6" lift and hopefully 37's to match

[DieselFeverDisease]

It's definitely weird! I'm glad it's working, but I hate it when sketchy things happen and then "fix themselves". That always makes me leery and it stays in the back of my mind.
Thanks for the compliment on my rig, Im slowly beginning to get it how I want it but I still have Sooooo much to do! Next on the list is a 4.5" or 6" lift and hopefully some black bumpers