Check the vacuum lines that run down to the front wheel hub bearings if they are good follow the vacuum lines up to the 4x4 vacuum solenoidon the firewall and check for a stuck vacuum valve
The 2001 Rubicon is FULL time 4x4 from factory. Unless you installed a 2x4/4x4 select then it should always be in 4wheel drive.
NO, The frames are made different.
2002 ranger wont go in 4wheel
If they are the original ball joints they can't be lubed.
Put the lever into the 4wd position.
Make sure your truck is not in 4wheel drive low it needs to be 2 high
I would start by checking vacuum lines
there should be a button on your left of the steering wheel and if not, it doesn't have 4 wheel drive
tow with the drive wheels up this will be our back wheels if you have 4wheel drive tow with all wheels up if you don't you have a good chance of causing tarnsmission problems because of the trans running with no fluid to lubribate the gears.
turn on the engine, shift into neutral, engage the 4x4, shift into drive.
It means there is no output from your ECM (Engine Control Module). You need a new one.
Well it depends on whether or not it has the 4wheel ABS upgrade or not. For some goofy reason, they offered 2wheel ABS standard and 4wheel ABS optional. Only real way to know for sure is to go look at the front calipers and if there's a split line then you have 4wheel ABS. You could also just go lock 'em up!