In this picture the pitman arm that came on the 4-bolt steering gear is placed on top of the pitman arm that comes stock on the Bronco. As you can see, the pitman arm from the 4-bolt steering gear is slightly longer. Although one "could" mount it up, there would be some geometry problems that would throw the alignment off. First, fitting the longer pitman arm to the Bronco would have the effect of bringing the front of the tires together slightly, increasing toe-in. While this could easily be corrected with an alignment, there is another side effect. Since the arc of movement with the longer pitman arm is greater, it could have the effect of skewing the amount of "differentiation of movement" between the two front wheels during turns. In a turn, the inner wheel must travel a shorter distance than the outer wheel. This means that when you turn the steering wheel, the inner wheel turns more than the outer in order to "synchronize" their respective movement in relation to the arc they must travel. A longer pitman arm may have the effect of eliminating this balance.

Owner caption December 2017 · Photo 6 of 53