I have a F-1 with a 4" drop axle and a Toyota P/S box. With the truck sitting at ride height it looks impossible to hook up the drag link from the box to the steering arm. Is it possible to use a rack? If not, I really am confused. Also, what will cause bumpsteer? Thanks!

 

Bump for some help.

 

A straight axle suspension is always going to have some bump steer, its just the way it is.

To keep bump steer to a minimum you need to have your drag link parallel to the plane of the axle. To keep it in simple terms, the drag link should be about parallel to the frame. If there is some wonky angle between the pitman arm and the axle then you are going to have problems.
I just replaced my front springs and removed a bunch of leaves to lower the truck. After driving it I ended up putting leaves back because I created a horrible angle to the draglink and caused major bump steer.

Bobby

 

Anyone with some more ideas?

 

Why won't the drag link connect? Is the pitman arm for the box thru the original frame hole? With a 4" drop axle you may need a dropped steering arm as well.
When a steering arm moves in an arc the vertical (or horizontal depending on orientation) distance it moves is not linear thru the arc, the greatest displacement happens at the center of the arc and decreases at the ends. If you steering arm is not in the center of the arc at straight ahead, it will move different amounts when it swings past neutral. When this happens because of suspension movement it is called bump steer. At extremes of misalignment it can actually reverse direction!

 

Thanks for your response. I bent my steering arm down to accomodate the drop of the axle, but my pitman arm ball is still 3 to 4 inches lower than my steering arm ball. Is it okay for the drag-link to run up hill?

 

That's a lot of angle which will give you some bump steer. You may need to build yourself a new drag link with a heim joint on the steering arm end and have it attach to a drop stud off the bottom of the steering arm. When you bend the steering arm, you must be careful that the bend is such that the ball end still swings horizontally or it too can cause bump steer. I'd suggest you contact the company that dropped your axle, they certainly have had to run into this issue before and should be able to offer the best solution. They wouldn't last long building axles that can't be made to steer properly. There is a company offering racks for beam axles, but I haven't seen an independent report on how well they work from someone who is actually driving one, and they are pretty pricey IMHO. I'd suggest selling off the front suspension you have now and replace it with a Jag IFS before investing in a rack. The Jag is such an easy install on an F1 it almost installs itself, sits as low as what you have now, and you can even get dropped spindles for it if you want to decapitate toads on the road.

 

I'm one for saving toads, but Ax is right. The rack on a beam is a last resort, IMO.

What pitman arm are you using? is it longer than stock?

 

Then pitman arm is stock length, I mated the Toyota big end to the F-1 ball end. What year jag are they talking about?

 

AX, and others

What about a stepped or "Z'ed" drag link?

Bobby

 

A Z'd linkage in a push/pull application like a drag link is not an ideal situation besides the potential for bending and flexing, that shape link has a tendency to want to rotate or twist to a horizontal orientation causing binding and more bump steer.
The Jag IFS is the 84(?) - 87 XJ or the XJS to the early 90's. Here's a major discussion with a lot of info links:
https://www.ford-trucks.com/forums/2...hlight=jag+ifs