It should engage when you shift the transfer-case onto 4-hi,or lo. It is actuated by a vacuum valve. If it isn't locking in,then you have either a vacuum leak,the diaphram(on the axle housing) is bad,or the mechanism on transfer-case is defective.
what front and rear end are in a 2001 wrangler sport 4.0
yes, the axles are a direct swap
try replacing the actuator valve on the front axle
no, they are entirely different vehicles
worn front end bushings, the death wobble usually needs track bar bushings but I recommend replacing them all with nylon when you do it.
Yes
Not really, anything that has been bent and is tried to be straightend will be weak.
Yes, the 35 is the standard rear end, 30 up front.
If it has square headlights and leaf spring suspension on the front end then it is a YJ
It may be a front U-Joint, or front driveshaft/cv joint.
Wrangler - University of Cambridge - ended in 1909.
you may either need new tires or a front end alignment.