Hi,i recently picked up this vehicle(automatic trans),and has a wierd noise in the front or mid front when going up hills at 45mph or faster.It has the manual shift for 4 whl drv.The light for the front being engaged is lit up even when shifter is in 2 whl.The noise sounds like a grinding,then followed by a bang..It last 20 to 30 seconds,and after bang.it's quiet again..I don't know much about 4 whl drives..Ive been told this has the cable to switch from 2 to high,and a acutuator.Other than that,no clues..Any info would be greatly appreciated..Thank You

 

Even though you have a shift lever on the floor, the front axle is still engaged by vacuum controlled by the switch on the transfer case. When in 4wd, engine vacuum is sent to the actuator located on the passenger inner fender. The actuator pulls on the cable that engages the front axle. Sounds like yours is either partially getting vacuum or the cable is frozen. Either condition can cause a partial engagement of the front axle resulting in the symptoms you are experiencing.

For more information, check out a few of the 4wd related threads in the Tech Article (DIY) Index link located in my signature below. The front axle controls for your manually shifted NV231 are practically identical to the electronically shifted NV233.

 

Great,thanks so much.Hopefully i haven't ruined any parts..

I was wondering,,I don't have a book on vehicle and thought i'd ask you..I found two hoses coming from back of motor to under battery.One went to the acuator,(smaller of the two) and the big one to nothing..Does this sound right?? Thanks

oh,never mind..Reading the 4x4 info you provided..Thanks a million for that.

 

I checked the actuator by hand,seemed to be okay for the most part.Held the air back by finger.I put it in 4 high,checked drive shaft..It was locked,but when i put it back in 2 whl.It was still locked.I found the vac hose from switch,and unhooked..The light indicator for being in 4whl went out,and the shaft turned in 2 whl.When i put in 4 high.It locked..Sound like a switch prob?? Thanks