Mechanical Jack problems of the 1998 Lincoln Navigator

We have had our Navigator into the dealership a total of 8 times in the last 3 years. The following had to be replaced: sunroof, groaning noise from beneath the hood (in 4 times for this still not corrected), cd player replaced, sterio replaced, heating elements both front seat replaced 2 times each, incorrect lug nuts, incorrect tire wrench, shaking in stering @ highway speeds-still not corrected, lift system broken-not fixed, hood latch would not release, fuse blowen 3 times for ac outlets, check suspension light on, check engine light on, rear turn sigal out, passenger window catches, incorrect spair tire. (tiresize: p265/70r17).

The instructions on the jack advise not to get under the car, but it is impossible to turn the jack handle unless you are under the car, the amount of force required to turn the jack handle is so great that a woman or a small man couldn't operate it. Nlm.