I dont know if you have found problem yet. I had a 2000 f250 superduty that did that same thing poppin, i pinned it down the the front axle the right side, hub was bad it kept poppin in and out, so i got new set of warn manuals and put on it it fixed the problem for a while and them it didnt want to stay in fwd, come to find out the wheel bearin was bad,, witch caused the hub to come loose inside, hubs were 100 bucks i think and wheel bearin was i think 250, hope this might help you out

Jake

 

Thanks for the comments. WIth this "out of Work" situation I am in, I am just going to have to park it for a bit until I can raise the funds for repairs. The taking a **** on the shop floor was enough for me to think about selling it, but I changed my mind. I am going to attempt to do the wheel bearings and u-joints after I fix the brake lines. Just gotta find a dry place to do it.