I am in the process of changing king pins. The truck was wandering quite a bit down the highway. Steering box, pitman arm, and drag link are in good shape. The springs do not have any lateral play with axle removed. The concern is that the front springs looked flat before anything was removed. I am looking for a measurement between the top of the spring pad to frame. Thank you.

 

They sit just about flat normally with a V8. Even a little convex across the top isn't out of reason. Top of the spring leaf to the bottom of the frame measures just about 3 3/4" to 4" - one of mine is sitting at each measurement. A step on the running board will level it out.... that's just the way these old trucks are.

 

As long as everything else is new or good, you might want to replace the tie rod ends too. They are very easy and inexpensive.

I'd check the steering box "lash" adjustment as noted in the Shop Manual.

Worn wheel bearing will also cause wander. But when I rebuilt my front end (kingpins, drag link, wheel bearings, tie rod ends, new springs/eye bolts/bushings) the biggest improvement was new tires.

Lastly, check your alignment. The toe in should be pulled in beyond spec if you are going to travel at freeway speeds - to about 1/8 "toe in"

Also you may want to check to see if you have any castor shims installed between your axel and spring (you should). These are wedges that "cant" the axel either more forward or back. For freeway speeds your caster angle needs to be at least 4 1/2 degrees.

Having insufficient castor angle and toe in will cause the front to wander significally!

Just FYI: the only way to adjust the Camber angle on these trucks is to bend the axel. So if you take it in to have it aligned, be aware that it takes special equipment to set that (so don't be fooled by the shop if they say they did it - ask them how they did it).

 

how do you adjust the lash? is it the nut on top or the side of the steering box? also where do you get shims for the caster angle. thanks alot

 

Yep that is the adjusting nut and screw on the side of the steering box.

Hmmmm. When I had my front end redone, they built custom springs that incorporated the caster angle at 4 1/2 degrees (and it made a tremendous diff.) I mentioned that the guys at the spring shop told me they had to do it that way because you couldn't find shims that were 1.75 inches wide.

BUT, I believe (and this is my feeble memory talking now) someone said Speedway has them. I'm not sure, you might want to check.

Classic Pickup Truck Parts

Or maybe someone else knows.