1992 f150 4x4 w/351 auto transmission, the hubs seem to be disengaging and engaging while driving. Don't know if it is actuator or ? Need some advice before I spend a fortune at a shop. Loud clunking every 2-300 feet, don't want to use 4x4 'till repaired.

 

i seem to be having the same problem and posted a thread yesterday, does your truck have the straight axel in the front? i was told from a friend that it might be the hubs but i need some more feedback, ive got manual locking hubs on mine, but im not sure if i should replace both or if theres a way to trouble shoot and find which hub it is, if the hubs are the reason. ill let you know if i find anything out. good luck bud!

 

Straight axel yes. From what I have read it sounds like an actuator or transfer case drive motor. I am going to take it to a shop tomorrow for repair, I will ley you know what the diag is. I don't think that is the hubs, I have full time not locking hubs and I haven't heard the hub answer. Good luck.

 

Replaced the transfer case motor, fixed the problem. No more engage-disengage, aneasy and inexpensive fix.