4wd issues

[southernboy2147]

what is the most common thing to make the 4wd go out on rangers? i have a 1999 4x4 5spd. the 4lo locks in gear ratio wise but the front tires dont pull. 4 high does not work either. any ideas?

 

[infantry grunt]

Hubs,maybe?Is the 4WD ingaged using the vaccum off your engine,also may be your problem,that happened to me on a Blazer I use to own.Try listening for hissing noises under your hood or close to your front drive.I may be wrong,but I think I understand that the newer Rangers have vaccum actuated 4WD

 

[RonD]

Yes, reads like the Pulse vacuum hub system is not working

Read here about the different "auto hubs" ford offered on Rangers
http://www.therangerstation.com/tech_library/HubDiagnosis.html

General consensus is to scrape any Ford "auto hubs" in favor of manual hubs, "on the fly" 4 wheel drive just isn't needed that much IMO, getting out and manually locking or unlocking is just not that big a deal.
Most discover their auto hubs are not working when they need 4 wheel drive, lol, like most things you don't miss it until you need it.
Even rebuilt auto hubs will most likely fail again and, of course, only when you need them.
Manual hubs are not bullet-proof but tend to last much much longer, and work when you need them.