CompuShift Plus, an easy to install computer shift control for XJ's, allows push button shifting in the 1-2 shift lever position. The CompuShift Plus also allows the Cherokee to start in second gear in mud, snow, sand, or other slippery surfaces.
We installed a CompuShift Plus in an XJ, and immediately noticed its benefits. In the dunes, where we needed to start in second gear low range because first gear was too low, the CompuShift Plus enabled us to start in second and climb the dune (before, when starting in first, we were unable to make the climb).
Trail riding was also easier, as that unexpected jerk of the Cherokee when the tranny downshifted to first gear low range was eliminated by the unit. Whenever we needed first, it was easily accessed by a push of the switch.
That late downshift to first gear in the new Grand Cherokee was an apparent solution to an early downshift situation in the smaller Cherokee with the 4.0 I-6.
If the transmission was manually downshifted to the
"1-2" position, it was possible for the transmission to
downshift with a jerk to first gear at approximately 28 mph. That
could be dangerous, especially while traveling downhill on wet or
icy roadways or when towing. It could cause the rear wheels to
lock and the vehicle to spin out.
....CompuShift Plus is a separate control device that uses a switch to manually control shifting into first and second gears. It also allows takeoff from a dead start in second gear, if needed. In Drive however, it will not affect normal transmission shifting."