[036speed]

i just got a 03 F-250 with the 7.3L. its a xlt 6speed manual with the fx4 package with 90k miles. its got the turn knob 4x4 which i thought i would like compared to the level 4x4 i had in my '95 460ci.
i drove 9 hrs to get the truck and i tested the 4x4 b4 i got it. but now when i turn it into 4x4 hi or lo it ticks when i go over 10mph or when i put normal torque on it. the guy said he rarly used it. it goes into 4x4 but makes a lot of clicking sounds like its not engaged all the way. i have gotten it to engage all the way twice now. thats it. i have been playing with it for a few hrs now rollin it back and forth. but no luck. i have also taken the whole asembly and cleaned it out. its still not engageing right. what do you guys suggest i do? would getting a new motor help? i am trying to avoid that. maybe it will start working over time? should i just keep playin with it?