4wd will not engage when lever is moved to 4Hi or 4Lo. 1992 Jeep Cherokee, 4.0L, Automatic.

You can "shift on the fly" at up to 45mph - just let off the gas and pull the shifter back to 4hi. DO NOT try going to 4lo while moving.

Another way is to stop, put it in neutral, and pull the shifter back to 4hi or 4lo.

This is vacuum activated - so if you can't get it to engage - the vacuum motor is failed - or you have a disconnected or rotted vacuum line.

Cherokees have the command - track. You'll see a lever next to the transmission shifter that has letters 2H, 4H, N, 4L on it.
You can shift from 2H (2wheel drive high range) to 4H (4wheel drive high range) at any legal speed.
If it's an automatic, I recommend just taking your feet off of both pedals, so there's not a lot of torque being passed thru the transfer case.
If it's a standard I recommend stepping on the clutch when you shift, but it's not necessary.
To go to Neutral just pull the shifter back one more position to the N position. To shift into 4L (4wheel drive lo range) you must be stopped.
I also recommend shifting the transmission into neutral when you do this. Push the shifter to the right, then pull it back.

Thanks!

Hi, 2hi is your normal driving selection, this is NOT in 4WD mode. Both 4lo and 4hi is for 4 wheel driving, 4lo is used in extreme conditions and will gear the vehicle down to a very slow speed with maximum traction at the wheels, 4hi is for general 4 wheel driving in rough terrain, if you have lights on the dash than it will come on when you change gears, hope this help

Try shifting the transmission into neutral then pressing 4hi. It should flash and then engage. Shift into drive again and re-try. Anytime shifted from 4hi to 4lo it needs to be shifted into neutral during transition. There is no need for 4lo position, unless you are really stuck off road, in the mud up to the windshield. Do not use 4lo unless you 4WD off road.

They shouldn't have any amnual hubs in the fornt axle. You simply have to shift into "4HI" position and its locked in. Some have a part time 4WD position but its not locked in 4WD all the time. Older models you had to turn a lever on both front wheels to lock. Some models its a switch on the dash to engage not a lever in the floor.

has anyone found the solution to this problem?

i think your anti lock/traction control system will cause this. does you truck have these options?

shift from 2wh to 4hi to neutral then 4lo all while in drive and moving slowly. The owners manual and repair books say you can actually damage the transfercase if the jeep is parked. You can go into 4hi at any driving speed, just not too fast!

what causes the 4wd to kick in when you have it in 2wd

your doing it right but your accuater is bad 59.00 auto zone easy install

idk check and make sure the front driveline isnt broke ,,????do you use 4wd alot going offroading???