Saturn & Warn-OD : Saturn & Warn Overdrive for Dana 18 Transfer Cases (#Saturn-OD)

Saturn & Warn-OD : Saturn & Warn Overdrive for Dana 18 Transfer Cases

4/5 (1 Review)

Please allow 4-6 weeks to ship

This all-range overdrive is a great addition to any of the early model Jeeps from 1940 to 1971, and I.H. Scouts 1961-65 with the Model 18 transfer case. The addition of this 25% overdrive unit offers you the needed gearing the early Jeeps were lacking. The Saturn overdrive is a fully synchronized unit that can be shifted-on-the-fly. When installing the unit, only minor modifications are required to the floorboard for the shifter. The Saturn is built to handle up to 300 ft./lbs. of torque, well within the range of a stock V8.

The Saturn is the original unit designed and developed by Warn Industries. Soon after their introduction, another unit emerged in Colorado by the name of Husky or Dual-A-Matic. The Colorado unit was identical in appearance, but in no way was it interchangeable< with the Warn All-Range. Both units were available for the early Jeep and Scout vehicles. The units were offered with the 6 and 10 spline internal assembly and the 26 or 29 tooth output gear. Both units were very popular in the mid-1960s, but it wasn't until the introduction of the Dana Spicer Model 20 transfer case in 1972 that production quantities started to recede. The Warn and Husky overdrives were no longer compatible. Both companies stopped production, and the availability of spare parts became very scarce by the mid-1970s.

Advance Adapters purchased the tooling, engineering data, & inventory from Warn Industries in 1991. The components we manufacture today are the same as the old Warn components. We have incorporated a few upgrades on the units we sell today, but these units are all still interchangeable with the original Warn overdrive. (Note: The Saturn is not compatible with the Husky unit.) The Saturn overdrive installs directly on the backside of the transfer case through the inspection cover. No cutting or modification of the drivetrain is required. No relays and electrical connections required.


Current Average Estimated Wait Time for New Orders
4 to 6 Weeks



Tech Vault


Top Review


by Desert Rat, from Switzerland

A Great Overdrive

I have had the Saturn (Warn) overdrive on four of my Jeep CJ5s over a 30 year period, two of which I still own. I recommend them highly.

Among other things, it makes highway driving far more bearable, cuts down on the noise, and you get a modest increase in highway mileage.

The overdrive is very easy to install, just remove the plate on the back of the transfer case, remove the cotter pin from the end of transmission shaft, pull the drive gear off, thread the planetary unit on, torque it up, get the star lock washer on, then bolt on the rest of the unit. The shifter bolts to the top of the transmission and the linkage is a simple rod. You can modify the bracket and linkage as needed. Probably have to cut the floor.

The quality of the unit was equal to the gears in the transmission, nice brass synchros, very well made. One of my Jeeps (overdrive bolted to a T-18 4-speed) had an occasional gear clash problem when shifting, possibly main shaft end play or lousy bearing or something,

Pity the Spicer 18 transfer case is a dying breed, though the Saturn overdrive compliments it nicely.