I have a 98 Lincoln Navigator

The switch on the dash works, the lights indicate that it is in 4wd, when I switch it to 4lo I hear it engage and the front drive shaft won't move when in 4lo (moves normally when in 2wd).

The actuator on the axle seems to be holding pressure, but nothing is being sent down to it. Don't seem to have a leak in a vacuum hose.

I have removed the 2 solenoids behind the battery for replacement but wanted some opinions before I spent the money. Any ideas?

 

By 'move' do you mean when trying to turn the DS by hand or when the vehicle is moving?

 

Yeah, by hand. When in 4low, on ice when I floor it, only the rear wheels spin (the others roll fine but are obviously not locked in).

I had no vacuum whatsoever to the actuator on the axle when I disconnected the hoses, not in 4lo, not when switched back to 2wd. The actuator wouldn't move when I held my fingers to the nozzles on it. Moved fairly freely otherwise.

I do have vacuum at the hoses when I disconnect the ones at the solenoids behind the battery (only one hose on each though).

Man, I'm stumped.

 

It sounds like you either have non-functioning solenoids or a break in the vacuum hose after to solenoids. Have you tested for power at the solenoids while switching in and out of 4WD?

 

I haven't. How do you do it?

 

Connect a voltmeter to the solenoid leads and turn your 4WD selector switch to the various positions and note any volts readings. Don't forget the key needs to be on.

 

I thank you much.