Twin-Stick Transfer Case

Oct. 01, 2005 By The Binder Bunch

Twin stick transfer cases are all the rage in Denver among the Binder Bunch Members. Although this might seem like a giant leap backwards in technology to the transfer case of old, still, there is a compelling case to be made for the change. It is important to understand that the Scout transfer cases (Dana 300 & 20) operate differently then the old twin stick transfer cases (Dana 18). Early CJ model 18 transfer cases used one shifter for 2WD. Neutral, and 4WD. And the other shifter was used for High range or Low range selection. With the Binder Bunch’s modified Dana 300 and 20 the twin shifters operate differently. One shifter controls the front axle High range, Neutral, and Low range. And the other shifter controls the rear axle High range, Neutral, and Low range. The twin stick shift allows you to override the interlock plunger between axles. This allows you to use 2WD Low range. It also allows you to have front wheel drive only.

The Binder Bunch enjoys the ability to switch the transfer case into 2WD Low while four wheeling. Especially when the Scout is pointed down hill and it is difficult to steer because of the Detroit locker in the front axle. By shifting the Scout into 2WD low range you can take advantage of the compression braking while maintaining your ease of steering. With a Locker in the rear you can usually handle most of the light four wheeling in 2WD. To prevent overheating of the motor due to lugging the motor in 2WD High range you now have the option of running in 2WD Low range. 2WD Low range allows you to keep the RPM’s up and not over work your motor.

Start the conversion by removing your Dana 20 or 300 transfer case from the Scout. Disassemble the transfer case. Mark the front and rear shift rods (part 18 & 19 in fig. 7). This is important to do since it is easy to mix them up. The first step once the rods are out is to weld up the slotted ends along with the retaining holes. After welding turn the rod ends down to the same diameter as the rest of the rod.

The second step is to notch the rods to accept the twin stick shift levers (fig. 3). A grinder or file is adequate for the job. Begin the notch 5/16? from the end of the rod you welded up. Make the notch 5/16? deep and 5/8? long to match the end of the twin stick shifters.

The third step is to remove the barrel shaped plungers ( part #17, Fig. 7). These plungers are what prevent Low range 2WD being engaged in a stock transfer case setup. If you do not remove these you will not be able to fully take advantage of the twin shifters. NOTE: Care must be taken while operating the transfer case shifters since it is possible now to put one axle in Low range and one axle in High range. (Not a good idea). Common sense must prevail here.

Finally reassemble the transfer case and install the twin shifters you acquired from a Dana 18 transfer case. These twin shifter levers come in different shapes. Depending on which transmission and main shift lever you got them out of you may need to bend the transfer case shift levers to clear properly. A stock twin shifter boat completes the installation. Newsletter
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