4x4 will light up but not engage?

[Ranger Business]

i have an automatic 4 wheel drive push knob and when i turn the knob to 4 hi it will light up like it is on but it will not engage into 4 wheel drive. when i put it in neutral and step on the brake and put it in 4 low it will clunk like it transfers in but then i will drive around and it will not be in 4 wheel drive? the light are not blinking and i checked the #27 fuse and its good? my front driverside hub blew out about 6 months ago and i got it replaced at ford. could this have anything to do with the problem? thank you!

 

[Chance]

is your front driveshaft spinning or no? My first guess would be the hubs. Especailly with those !@#$in pulse vacuum hubs.

 

[railman]

yeah, you may have a vacuum leak, or another bad hub.....

if ya hear it "clunk" into 4 lo, i would say 99% sure it is the hubs...

worse case scenario is ya blew your front ring and pinion or spiders

l8r, John