The hubs lock through a vacuum mechanism. There is a collar of sorts that
slides over two splined shafts to connect them, this collar moves on command
of a vacuum system. Sometimes the shafts and collar can bind, and going in
reverse will release the bind and allow the collar to move back to its home
position. This is not in the manual because it is not "required". It is
helpful though. You can also release the binding, if present, by changing
the load on the drive train, you can do this by letting off of the gas and
turning the steering wheel from side to side.

If you shift out of 4WD, and can hear the resulting clunk from the movement
of the collar, then you do not have to do anything else. In theory, all you
need do is shift out of 4WD, and eventually the vacuum system will pull the
collar back to its home position. In practice, the collar can stick and the
remedy is to try going backwards for a few feet.



> wrote in message
ups.com...
> I just purchased a 2nd-hand 1994 Cherokee with the 5-speed manual,
> part-time 4WD tranny. The previous owner told me that you needed to
> back it up to unlock the hubs after having it in 4WD. I had to do this
> for my 88 Trooper. But I haven't seen anything in the Jeep owner's
> manual about backing up to unlock the hubs.
>
> Do I need to back to unlock hubs, or not?
>
> thanks,
>
> Tom
>