pitman HELP-update

[bronko69er]

I think you need a longer pitman arm as well.
Does it feel kind of hard to steer?
I'd start looking for one a little longer.

I still dont see why I need a longer arm?

This doesn't make sence to me either.
Wouldn't a longer pitman arm make it harder to steer?
Torque = Force X Distance,
If the required force (to move the draglink) stays the same, and the distance from the shaft increases (longer pitman arm), the torque required to turn the shaft increases.

 

[kntr]

Does every thing look good to go? Angles and such?

 

[bronko69er]

Nothing jumps out at me as way off.
Obviously the angle is not perfect and the lengths are not super close but it looks close enough and if it drives fine then great!
The ideal situation is to have them the same length and paralell but that is not always possible. In order to get enough angular travel out of the lower joint on the drag link, it typically needs to be placed out near end of the tie rod. Since you can't put the trac bar out near the end of the axle, the ideal setup cannot be achieved when increaed angular travel of the lower drig link joint is required. So there are small compromises we make to each of the variables to minimize the differences in lenght and angles.

 

[broncoguy66]

Well, I've got the toyoda setup, and with the Chevy tierod ends on my 3.5" lift I don't have much of a problem at all. It's starting to loosen up but I think that's just things wearing out. People thought that once you reamed out the yoda box for the chevy end there wouldn't be anything left. I haven't had it break yet. The cheby rod ends are wearing out before the arm has broken.

 

[welndmn]

This doesn't make sence to me either.
Wouldn't a longer pitman arm make it harder to steer?
Torque = Force X Distance,
If the required force (to move the draglink) stays the same, and the distance from the shaft increases (longer pitman arm), the torque required to turn the shaft increases.

You have the right thinking, just on the wrong plane, think of it from the drag link area.
With the drag link angled out that far, you loose some steering force and steering travel.
The reason I asked if when I had that setup, i noticed it harder to steer and less travel.
If you don't notice it, then don't mess with it ;D

 

[bronko69er]

You have the right thinking, just on the wrong plane, think of it from the drag link area.
With the drag link angled out that far, you loose some steering force and steering travel.
The reason I asked if when I had that setup, i noticed it harder to steer and less travel.
If you don't notice it, then don't mess with it ;D

Ok, I see where you're comming from.
Excuse the math while I prove it to myself.

Assumptions:
The drag link is paralell to the groud (just for calculation purposes) since in both cases the drag link angle with respect to the ground is almos the same, we can assume it's zero.
Ideal drag link angle of 5 degrees (in front of the tie rod).
Drag link length is 36" (for calculation purposes).
New drag link angle (with a shorter pitman arm) 15 deg (in front of the tie rod).

With a 36" drag link @ 5*, the force in the drag link is .4% greater than the force in the tierod.

With a 36" drag link @ 15*, the force in the drag link is 3.4% greatet than the force in the tierod.

A force differential of 3%...... OK so there is a small difference.

 

[kntr]

Where would I get a longer Toyota pitman?

 

[pondscum]

Here is a website for you to look at. http://www.sky-manufacturing.com/steering1.htm
I have not purchased from them but I have a couple toyo friends and "they say" seems ok. Hope this helps