Suzuki Samurais have proven nimble and capable off-road. However, as with many 4WDs, some Samurais get modified to be far bigger and badder than the OE engineers ever envisioned. Companies continue to innovate ways to allow Suzuki enthusiasts to run big tires and push the limits of these vehicles far beyond what they were designed to do. Samurais were designed as a budget vehicle, and the transfer case is one place where carnage can occur on rigs used for hardcore wheeling.
Sector 4 (S4) Offroad Innovations is one company that has developed upgrade parts for Samurais, including S4’s Overbuilt Output Kit. It replaces the front 4WD output assembly with a heavy-duty billet housing and pairs it with cable-operated twin-stick shifters.
From the factory, the transfer case (like most) allows three operational modes: 2WD high, 4WD high, and 4WD low. A twin-stick modification allows the transfer case to use 2WD low, allowing complete independent control of all transfer case modes. An additional benefit of running a cable setup is that the shifters themselves can be mounted almost anywhere. This kit, as with many of S4’s products, uses stainless steel hardware for increased corrosion resistance.
We went to Zuks Off Road in Camp Verde, Arizona, to see Suzuki guru Myron Thorson install S4 upgrades on a Samurai transfer case. Hardcore drivers who push the limits of their Samurais should know there is some risk of blowing up the front output, and here is one solution to fortify this portion of the drivetrain. The conversion on a workbench took less than two hours. It’s not very complicated and can be done with common mechanic’s tools and a shop press.
The Sector 4 (S4) Offroad Innovations kit includes a billet aluminum front housing, new shift rails, a twin-stick shifter assembly, shifter cable assemblies, and new stainless hardware.
Myron Thorson of Zuks Off Road in Camp Verde, Arizona, started disassembling the transfer case by removing the front output flange and the input flange. A bolt-on bar helps hold each flange while the nut is removed.
Once unbolted, the front housing comes off along with the front output shaft.
The shift rods are held into position with spring-loaded detent balls that engage with notches in the shift rails. Here Thorson removes the detent plug on the underside of the case to release the spring and ball for the high/low-range shift fork. One of three factory detent balls will be discarded to enable full function of the twin-stick shifter.
It is necessary to split the main case halves to access the high/low-range shift fork to replace the shift rail, but it’s fairly simple to do. Once the center housing (shown) is removed, the counter gear and shaft can be pulled out, allowing the high/low shift fork to be pulled free of the housing.
The front output shaft is press fit into the bearing in the front housing, so the shaft needs to be pressed out of the bearing and removed.
Here is a quick comparison between an early 1986-1993 front output shaft (right) and the beefier 1994-on version (left). If you are in your transfer case already, it is probably a good idea to upgrade to this stronger front output shaft if you don’t already have one.
Here you can see both of the shift fork assemblies. The stock rails need to be removed and replaced with the new S4 stainless rails, which are a bit longer.
Once the roll pins are driven from each shift fork assembly, each rail can be pulled free. New rails are slid in and secured with the stock roll pins.
Here is the high/low shift fork being slipped back into the gear assembly. Then the center housing can be reinstalled with a new gasket. Copper RTV is an alternative to gaskets for sealing the housing surfaces.
The front output shift collar is reassembled with the 2WD/4WD shift fork that had been removed for shift rail replacement.
Once the front output shaft is pressed into the new S4 billet front housing, the housing is bolted in place with a new gasket. It’s helpful to put the case alignment tubes in the center housing first to aid in gasket placement and seating the S4 front housing.
Here you can see the S4 front housing being bolted in place. A new seal was installed for the output shaft, and you can see the longer shift rails protruding from the housing.
The spring and the detent ball for the high/low shift fork are reinstalled in the housing.
S4 provides a small cover plate with rubber O-rings to seal the shift rails. It’s bolted to the new front housing with stainless hardware.
New stainless shift rail plates are included and installed on the end of each shift rail.
Clevises on the end of each cable hook to the new shift rail plates with cross pins and cotter pins.
This included mount secures the shifter cables to a bracket at the transmission mount and grommets are included for routing the cables through the body floor. Cables can be made in a number of lengths to accommodate any shifter location.
Here is the complete, upgraded transfer case with the remote cable shifter assembly. The S4 front housing is super beefy, but still fits in a Zuks Off Road Super Cradle T-case mounting system.