Four wheel drive wont engage

no year car.
no model jeep stated.
now 4wd option stated (
command trac, Select track. quadra-trac/drive?,)
or if unknown what transfer case is there (tag on rear says)

the front axle have the vacuum valve on it.
does it work, the vacuum servo ( test it?)
if no vac. servo there, that is the newer jeeps.

is this your jeep?

There are 2 models here the push button will flash if the system is not engaging or disengaging properly . If front drive shaft is turning. That is with car raised and supported . if front drive axles do not turn then the axle actuator is not engaging axle shaft passenger side. Remove actuator and manually engage shifting collar with a screwdriver still does not turn then inner axle is twisted.

Check the soildnoid that engages 4x4 by switching it from 2 to 4 wheel drive and listen to it 27 dollar part if needed to be replaced

On the Jeep models, ESP means electronic stability program which is the same as traction control.
There are 3 different versions of four wheel drive on Jeep Grand Cherokees with the base version being all wheel drive.
Your owners manual should tell you which version you have and how it operates.

The switch is to put the vehicle into four wheel drive for off-road and increased traction on snow and ice.

could be, there are lines that run to frt diff, theres a vacuum reservoir that stores vacuum that comes from engine then theres aline tovacuum control switch then to vacuum swith to light the 4wd light and a line to shift motor that engauges the front wheels, check all these line and you might find a bad leaking line hope this helps.

With any four wheel drive you should always stop and back up ten feet when ever taking it out four wheel drive. This helps to unlock the gears so they can disengage and helps ensure that it isn't still in 4WD.

Sounds like the splines on your transfer case gear are ground down

They didn't make Grand Cherokees in '86, so I assume you mean '96?

I'm also assuming it is indeed a 4x4 and not a two wheel drive...sorry, I have to ask!

All the V8's GC's were Quadra-Trac. Please confirm this with what is label on your shifter. If so, it should say "4Hi, N, and 4Lo".

The Quadra Trac system has a viscous coupling. Meaning, that when the rear wheels start to slip, it heats the coupling up, and engages the front wheels.

This system typically put about 95% of the power to the rear wheels, and only about 5% goes to the front during normal driving, so it's essentially in 2wd mode.

When you put the transmission shifter into neutral, and pull your transfer case down to 4lo, then you have all four wheels locked. Do not drive like this on dry pavement.

To answer your questions, the 4x4 should automatically engage when the rear wheels start to slip. It is a seamless transition and you really won't be able to tell.

If you're in real bad snow, then pull it down to 4lo. That'll lock all four wheels in and give you greatest traction.

Drive safe.

Hi, I had a 88 cherokee, had no 4 wheel drive, the vac. motor u r referring to engages the 4x4. Mine vac motor was replaced, fixed the problem.