Im losing my **** with this 4wd. I need to get this fixed before winter. I have replaced my vacuum actuator, Transfercase switch, and 4x4 still doesnt work. I jacked the car up and (still in Park) put it in 4hi. I turned the front passenger wheel forward and it seems to have a click nose everytime it makes a full rotation. Now, this car was passed down to me from my sister. Last summer she had the 4hi on during the summer for possible up to a week. She drove on the highway a lot in that time too. Anyone possibly know what my issue may be?

 

Is it that the front axle is not engaged or is the transfer case not engaging?

A test to do is to jack up the front to get the wheels off the ground with the engine running and in Park. This setup ensures there is vacuum applied to the front axle engagement mechanism to engage the passenger side axle shaft to the differential, and so that there is vacuum applied to the transfer case switch. If it is all working the front driveshaft will be engaged at the transfer case and therefore locked because it is in Park.

Then you try to rotate either of the front wheels by hand with the other wheel free to rotate and with it prevented from rotating.

If rotating one wheel causes the other wheel rotate backward with the front driveshaft not spinning, and if the you cannot rotate one wheel when the other wheel is prevented from spinning, then it is all working correctly.

If rotating one wheel does not cause the other to spin the opposite direction, the passenger side axle shaft is not engaged.

If rotating one wheel with the other prevented from rotating causes the front driveshaft to rotate, then the transfer case is not engaged.