4x4 seems to be engagin by itself

[karranger]

sometimes when I get in the truck and start to move, gears sound like they are trying to engage. Clunking, grinding sounds. I will park the truck and come back later to find that I can use it. Any suggestions on what to look for would be appreciated. Thank you, Ken

 

[RonD]

Welcome to TRS

Manual or automatic trans?

Engine size?

Clunking and grinding from transmission area or the front wheels?

Have you shifted into 4WD high and also 4WD low and then back to 2WD?
Does it seem to shift in and out of 4WD OK?


1998 will have Pulse Vacuum hubs(PVH), not one of Fords better ideas
Read here on those: http://www.therangerstation.com/tech_library/troubleshoot-fix_pvh_hubs.shtml

This would only cause noises at front wheels.