Why does 1987 jeep 4 wheel drive stay ingaged?

Answer 1

It shouldn't... Perhaps the hubs are locked and not free You did not mention what kind of Jeep you have. That is important since that would tell us if your vehicle has a "shift on the fly" system or manual locking hubs. I believe you have a Cherokee. This vehicle had a 4 wheel drive system that allows you to shift into part time 4 wheel drive while you are moving forward at speed. Pulling up on the short lever to the left of your transmission shift actuates a vacuum switch that engages a front axle locking device which allows power to turn the front axle thus giving you "4 wheel drive". Sometimes this locking device does not unlock the front axle when the lever is returned to it's 2 wheel drive position. This is because the gears "bind up" and need some opposite force to unbind them. Simply put the vehicle in reverse and gingerly backup then stop and go forward again repeating the process until it "pop" out of 4 wheel drive. I believe that as the vehicle ages the mechanism doesn't seem to respond as it did when it was new and the vacuum is not sufficient enough to unlock the gears that are bound up. Another factor is most people only use 4 wheel drive in bad weather so it doesn't stay well lubricated. I would suggest that periodically you shift in and out of 4 wheel drive even when you do not need to. That way it will be ready to go when you do need it.