I had been having codes P0171 & P0174 come up on my check engine light so I checked around and found several air leaks on the vacuum system one of which was both air lines that go to the lockout hubs on the front wheels. When I was getting the codes before I still had 4wd if I switched to 4wd or back with the bad air lines. Now after I replaced the lines it seems to not want to lock into 4wd all the time when I switch back and forth. I did not clean the metal lines out when I replaced the hoses and am wondering if that could be part of the problem and if I did how would you go about it? Or is there a recommended procedure in going from 2wd to 4wd? Thanks

 

1998 to 2000 Ranger 4x4s used PVH(pulse vacuum hubs), Ford instantly knew this was a bad idea, so by 1999 some Ranger 4x4s were getting Live Axles in the front, by 2001 ALL Rangers got Live Axle, full time locked front hubs, so 2WD or 4WD was just in transfer case.

Anyway, you can chase the PVH problem and possibly fix it
Or you can lock PVH hubs full time like 2001 and up Rangers.
Or you can swap in AVM/Rugged Ridge Manual hubs

repair is here: Troubleshoot / Fix Your PVH Hubs : The Ranger Station

full time lock here: Permanently Lock Your ?98-?00 PVH Hubs : The Ranger Station

manual hub upgrade here: 1998-2000 Ford Ranger Manual Locking Hubs : The Ranger Station


When you want to check if you have a vacuum leak causing codes 171/174 there is an easy test
After engine is warmed up and idling, unplug the IAC Valves 2 wire connector
IAC Valve will close and RPMs should drop down to 500 or so, engine may also stall, either is good it means no vacuum leaks

If idle stays at 700 or higher then there is an air leak

 

With the "Rugged Ridge" manual hubs do you have to lock and unlock the hubs by hand verses the dash switch?

 

Yes, if you want to.

Most just leave them Locked in winter months, or year round, and you can then "shift on the fly" from 2WD to 4High same as before.

Transfer case shifts from 2WD to 4WD, hubs have nothing to do with that, hubs connect axle to wheel, thats the only purpose

2001 and up Rangers have Locked hubs full time, MPG difference was set at .2 or .3 MPG if memory serves, so not much difference running locked hubs.

But you would have the option of unLocking if you wanted, 2001 and up owners do not have that option

 

Hubs are on the way. Thanks

 

Got the hubs on and they work like a charm. I would of done it a long time ago if I knew it was that easy to do.

 

Good work

Thanks for posting the update and the FIX