Dana 20

Dana 20 Transfer Case Specs & Information

The Dana 20 is essentially an improved version of the Dana 18. The evolution from the Dana 18 to the Dana 20 resulted in a significantly stronger, quieter, and more reliable gear box. Visually, the two transfer cases are very similar and easily mistaken for one another. The common "C18-15" markings on the Dana 20 housing don't help avoiding confusion either. And while the Dana 18 guts will slide into a Dana 20, the Dana 20 housing is more robust and thus favorable. Early Ford Bronco versions of the transfer case are desirable, but won't mate to a Jeep's transmission.

The Dana Spicer model 20 transfer case is a light weight, rugged evolution of the Dana 18. It was most commonly used in 1962 to 1979 Jeep vehicles, though it can also be found in the International Scout, Ford Bronco, and Chevrolet Blazer for select model years. The 1966 to 1972 Bronco version of the transfer case had a favorably lower 2.46 to 1 low range gear ratio, compared to the Jeep's 2.03 to 1. The guts of the Ford transfer case can be adapted into that of other models in order to upgrade to the lower ratio. At 10 1/2 inches long, the case is relatively compact and praised for its strength, especially in comparison to the Dana 18.

The factory shift arrangement uses a single shifter to select between 2 wheel drive, 4 high, neutral, and 4 low. However, twin stick kits are available and relatively affordable. Twin sticking the Dana 20 will allow for independent engagement of the front and rear axles in both 4 high and 4 low, allowing for power to be transfered to either the front axle, rear axle, or both. Additionally, TeraFlex produces a 3.15 to 1 low range kit for the Dana 20, which significantly boosts its effectiveness as a box for crawlers.


Dana 20 Specs




Part time, gear drive


• 1962 - 1979 Jeep
• 1965 - 1979 International Scout
• 1966 - 1977 Ford Bronco
• 1969 - 1973 Chevrolet K5 Blazer

Case Material:

Cast iron

Shift Type:





High Range:

1.00 : 1

Low Range:

2.03 : 1 (Jeep, Scout, & Blazer)

2.46 : 1 (1966 - 1972 Ford Bronco)

2.34 : 1 (1973 - 1977 Ford Bronco)

4x4 Shift:

(front position) 2WD - 4 HI - N - 4 LO (rear position)

Input Splines:

6 or 10 spline

Output Splines:

10 spline (early models), 26 spline (late models)

Pass/Driver Drop:

• Jeep, GM, IH - Passenger side drop
• Ford Bronco - driver side drop


~ 80 lbs


1310 front and rear output yokes, fixed

Fluid Type*:

OEM fluid requirements varied, 80w-90 gear oil is typical

Fluid Capacity:

2.75 pints (1.375 quarts)


Quieter and stronger than the Dana 18. Lightweight, compact case design.


Early Ford Bronco version is the most desirable, yet the unique bolt pattern will only mate to Ford transmissions.

*Required fluid type and fluid capacity may vary with application and model year - refer to vehicle's owner manual.