Not only are the gears very large, they are also supported with axial thrust bearings between each gearset and Timken roller bearings between the gears and supporting shafts. Then there are tapered bearings where the case supports the shafts that the gears ride on. All this equates to a smooth spinning box and reduction in drag even with the big heavy gearsets.Not only are the gears very large, they are also supported with axial thrust bearings betw We really like the fact that the Monster box uses no gaskets or silicone, but rather O-rings to seal against leaks. This not only helps in assembly, but also allows for cleaner dis- and re-assembly down the road if you ever wanted to. Currently 23-spline inputs are offered and 32-spline outputs front and rear are standard, though other options are in the works. The Monster Box case is made of two halves with four locating dowel pins and 20 31/48-inch stainless Grade 8 bolts holding it together.We really like the fact that the Monster box uses no gaskets or silicone, but rather O-rin The tapered bearing preloads are set with shims that are held in place with aluminum caps, which are also O-ringed and bolted in place with six 31/48-inch bolts. Also note the three shift rails that ride on bronze bushings.The tapered bearing preloads are set with shims that are held in place with aluminum caps, The final case weighs in at 153 pounds dry and is quite enormous when compared to a Jeep CJ Dana 300 (right rear) or a Jeep TJ NP231 (left). Even though the case is heavy, it is not much longer than a 300, at just 13 inches from front to back. Final specs are 9.77 inches tall and 19.12 inches wide. Plus the Monster Box is available with either driver- or passenger-side front outputs, and uses standard off-the-shelf Spicer yokes or flanges for different driveshaft joint or CV choices.The final case weighs in at 153 pounds dry and is quite enormous when compared to a Jeep C The shift-rail detent balls can be supported by different rate springs to adjust how much effort is needed to shift, plus the vents are all outfitted with check valves to release or accept outside air only when pressures require it. However, the case does not have a mechanical speedometer drive, but it does have a Mopar speed sensor and four-wheel-drive light switch since many 4x4s need it in order to keep their engine ECMs happy.The shift-rail detent balls can be supported by different rate springs to adjust how much The STaK engineers said the hardest puzzle of this project was the shifters. The goal was three shifters that come through the stock floor openings of a Jeep, didn't rattle, and are easily shifted. The version we saw had the rear-most lever activating the rear axle in either High Neutral or Low, and the middle lever activates the same for the front axle. Then the front-most lever chooses between 3.05:1, Neutral, or 5.44:1 low ranges. We found the shifting a bit confusing and tight, but a revised system is in the works as well as possible pneumatic or solenoid shifters that wouldn't even require levers if the customer requests it.The STaK engineers said the hardest puzzle of this project was the shifters. The goal was Here is the biggest issue we found with the Monster Box: its sheer size. In fact, the STaK team has found that using their forklift to help install the case in a stock Jeep TJ is much easier than having two guys bench-press 150 some pounds up and onto the transmission. We're slightly concerned about all that weight hanging off the tail of an aluminum manual or automatic transmission, but there have not been any issues thus far. STaK is working on a new mounting unit to better support it. However, the case can be mounted in 25 different clocking positions in 4-degree increments for nearly any 4x4 you are building. The Monster Box fits in a Jeep just fine, and though STaK won't make any claims about its strength, it seems more in the size range of a fullsize truck NP205 rather than a 11/44-ton Jeep transfer case. When installing in a Jeep you will need to shorten the front driveshaft 2 to 4 inches and get a new rear driveshaft. Though designed with Jeeps in mind, the Monster has adapters available for nearly any transmission you would want to put it behind. We would like to put one in a monster fullsize truck with huge tires and some serious engine or a crazy all-around trail buggy. Heck, we'd even consider one for our daily driver/weekend warrior 4x4. With a case this beefy and with so many gearing choices, the options are endless. SOURCES STAK 4x4 « | 1 | 2 | View Full Article Enjoyed this Post? Subscribe to our RSS Feed, or use your favorite social media to recommend us to friends and colleagues!