i have a 99 3.0 ranger 4x4 that wont shift into 4x4. it has electronic shift on the fly. The dash light 4x4 comes on, and will shift into low range but front axle doesn't pull. I havent checked the servo motor or anything but just wanted to know if there were any simple common problems w/ this truck I could look for first. I am going to put it on a 2 post lift this afternoon to see if thew front driveshaft is turning while engaged to eliminate the servo and tcase. If they are working should i look at the hubs first or go to the diff? Thanx

 

Front hubs are vacuum actuated, so if you have a leak they dont work. Also if there is dirt or sand in the hubs they dont like to engage. A mod is in the how to section on locking the auto hub into full time 4wd.

AVM sells a manual hub upgrade.

 

I had the same problem a while back. I took a look at my hubs and the passenger side looked barns new but the driver side was caked with mud and rusted but I wire brushed it and greased it up and havnt had a problem since. Good luck.

 

Hey where is that How To you mentioned above, I went through them, maybe I overlooked it a few times.

 

i believe the vacuum leak is spot on. if you go heavy throttle the heat or air acts up so i def have a vacuum prob somewhere. are there any common vacuum hose problems

 

WYeah. W these trucks anywhere there is a vaccum hose is a common problem. W the heat and air prob I would look for a black vaccum ball on passenger fender and check hoses going to and from it.

 

thanx. i may just start pulling and inspecting hoses and replace until its fixed

 

You absolutely have leak my guess is between the reservoir and and the engine.

There is a black line running the the intake to the pass side wheel well area.

 

ok thanx ill get to lookin this afternoon if possible.

 

well never did find the vacuum reservoir. Im pretty sure mine doesn't have one. I have 2 sensor looking items that have hoses going to them and the intake manifold has 2 ports on it along w/ the 1 on the intake tube. i pulled the inner fender on passenger side down at rear but no ball. i went ahead and did the hub mod so my 4x4 works but the air is still acting up

 

to get to the reservoir, you need to take the passenger front wheel well liner out....mud flap comes off and a few other bolts and it comes out with some bending. That reservoir is tucked away up in there....but it is there.

My vacuum solenoid assembly (what pulses the vacuum) failed...the diaphragm went out. I changed out all the soft lines until I couldn't find any more. If you have access to a vacuum gauge, it'd help a lot. I used a Mighty Vac w/ gauge that is also used to change brake fluid.