I'm considering putting in a 4" lift kit on my '56 3200. Can anyone advise on whether or not I will need a new pitman arm? Any other linkage that will need modifying or replacing? Thanks for the help.
Bump steer will occur when your drag link is not close to parallel with the ground. A longer Pitman arm (to make the drag link parallel with the ground) would have the effect of quickening the steering ratio, making it harder to turn the steering wheel, especially when stopped.
Not sure I understand what "bump steer" means? Without P/S, it can't get any harder than it is now, though. Got any recommendations?
Bump steer occurs when vertical movement of the I beam front axle (hitting a bump or pot hole) causes the distance between the end of the pitman arm and the end of the steering arm to change. Problem is that distance cannot change because it is held constant by the drag link. So the whole system responds by either turning the steering wheel one direction, the front wheels the other direction or some of each. The shorter the drag link is the worse the problem is. The farther away from horizontal the drag link is the worse the problem is. It is just geometry. My recommendation is to NOT USE THE POWER STEERING SYSTEM FROM B*ROTHERs. It has a very short drag link (about 1/2 of stock) and was very dangerous with I first installed it. A decent bump would try to send my truck into the next lane to the left. The standard pitman arm caused the drag link to be around 10 degrees off of horizontal. I changed out the pitman arm for one that was designed for lowered front ends (even though mine wasn't) which brought the drag link through horizontal to about 3 degrees the other way. Much better, but still noticable, especially at speed with a bump that doesn't go straight across the road. Properly inflated and not too wide tires will go a long way towards reducing turning effort.
Thanks for the insight. What I'm planning is probably far less thorough than most would do. I have machined aluminum blocks that will lift it 3" or 4" (haven't decided yet), and the only piece to solve is the pitman arm/drag link. Do you know of a source for a extended drop pitman arm for this old pickup?
