I have 03 F250 with warn premium hubs. A few months ago the LF kept kicking out while locked in. Warn told me to check the needle bearings and they were gone. I needed the truck so I replaced the whole hub instead of trying to the old bearing shell out. I have driven 800-900 miles and no issues. All dry pavement so 4wd was not used. Two weeks ago in 2wd on pavement it started binding up with what I thought was the front end. I made it home and found that the lockout cap was still tight to the hub with the 6 screws, but there was a 3/16 to 1/4" gap between the end of the cap and the hub.
Warn told me that some aftermarket hubs may have the ring groove cut too wide and sometimes it would require 2 snap rings to keep it from sliding out. Thought I found the problem and a 2nd one was installed. I drove out of the driveway today and did not make it 200 yards before the problem started again. It acts like something is trying to lock up and then bogs down. The left front cap at the time did not feel right compared to the other side. It was lightly cleaned and oiled with a new spring and washer put in. I was frustrated when I got back tonight and have not looked at it since. Any ideas on what I need to look at next?
Thank you

 

Do you have a car jack to jack up each tire?

Lift each tire up and spin them, listen for any grinding, grab it each way and try to wiggle it to see if the hub
or any ball joints might be going back. Its usually very obvious if something is going wrong because you'll have slop where you shouldn't.

If everything checks out I simple to a hub tear down and rebuild & clean and compare each side for any wear or damage from something going wrong.

 

Found the problem last week. Not at all what I was expecting, but feel like I got lucky. RR emergency brake shoe/ assembly came apart and was catching on inside the back of the hub.