All 66-77 Broncos came with the Dana 20 transfer case. The most notable differences between the Bronco Dana 20s are the early version 66-72 known as the T-shift with 2.46 low gear, verses the J-shift which was used from 73-77 and has a 2.34 low gear.

Early 66's had a round shift knob. Later 66-72 used the T-shifter which has a push button T-handle. All 66-72s shift in a straight up and down pattern while the 73-77 used a J-shifter. It has a backwards J-shift pattern. Front output shaft and bearings, shift rails and detents are also different from early to later Dana 20s.

Dana 20 Rebuild Kits

WILD HORSES kits include all the bearings needed to build your early and later model Dana 20. Yes, you will end up with 2 bearings you don't use but this way there is no chance of coming up with the wrong bearings on rebuild day! We offer 3 levels of rebuild kits. The basic kit includes gaskets, seals and bearings. The deluxe kit adds a new cluster shaft with thrust washers and shims. The super deluxe kit has all of the above plus the adapter housing bearing.

Gear Ratio Calculation

How low can you go? Take the lowest gear in your transmission and multiply that by the low gear in your t-case and then by your ring and pinion gear.

Example 1: NP 435 first gear is 6.69 x 2.34 in your T-case x 4.11 ring and pinion = 64.34 which we would call 64 to 1. Not bad.

Example 2: Now let's throw in a Dual T-case. NP 435 first gear is 6.69 x 2 in your Super Crawler x 2.34 in your T-case x 4.11 ring and pinion = 128.68 or 128 to 1.

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