Dubbed ‘i’ for integrated, the BlackBox-i is the second
evolution of the underdrive series. Designed to be as short and compact as
possible, the BackBox-i was specifically developed for short wheelbase
vehicles; jeeps, early broncos, and rock buggies. To meet these goals, the
design process had to start with a clean slate.
Setting aside all previous notions of gearbox fitment, we
removed the typical male/female splined connection at the transfer case saving
up to 4”. Having done away with the stock
transfer case input shaft, we replicated its internal dimensions right into the
back of the BlackBox’s mainshaft. This
allows the Blackbox-i to fit inside and fully integrate into the transfer case, saving a dramatic amount of
gearbox assembly length.
Replacing the input
shaft and housing, the Dana 300 input gear directly splines onto the BlackBox
output shaft, making this a very compact 5” long BlackBox-i. Need to adapt to a different transmission? The
BlackBox’s wide variety of input shafts takes care of it at the same time.
Bronco Dana 20
Replacing the long
factory input shaft and bearing retainer, the 6-spline input gear mounts
directly to the Blackbox output Shaft.
This adds up to a compact 5.188” long gearbox assembly that can now also
be easily adapted to a wide range of transmissions.
Atlas II - The Shortest
The BlackBox-i for the Atlas-II replaces the stock Atlas
input shaft, as well as the 1” thick bearing retainer and clocking ring. This
system only adds 4” over the stock Atlas-II! The BlackBox-i for the Atlas is
compatible with all gear ratios, and both the older 6 spline, and the new 32
spline input gears.
Hero 2 & 3 Speed
The BlackBox-i for the Hero 2 & 3 Speed Transfer Case replaces the stock Hero input shaft, as well as the 1" thick bearing retainer and clocking ring. This system only adds 4" over the stock Hero Transfer Case! The BlackBox-i is compatible with all gear ratios but does require the input assembly to be shipped to us for gear to be installed. (Yes this turns a 3 Speed into a 6 Speed!)