Bump steer

[69SKCharger]

My 69 Charger drives straight, doesn't pull and no vibration in the steering wheel. It's all stock front end components except fast ratio pitman arm and idler arm. I had a recent wheel alignment and asked the guy to try and get it to the top end of spec in terms of negative caster. Still, when driving down the highway, grooves in the pavement, bumps and really any form of unevenness seems to pull the car around. Looking for possible solutions. The only thing that comes to mind for me is the steering gear (manual steering), everything else seems fine. Could the gear be my issue? Other suggestions? Also, tires on the front are 235's, so not overly wide.

 

[68Moparmaniac]

Sounds like slop in the steering gear/front suspension. It shouldn't wander like you described if the components were still good.

 

[Darter6]

Or too much negative caster. Can cause tracking issues.

 

[Frank Mopar]

I hope the OP meant positive caster.

 

[69SKCharger]

Yes, sorry, positive caster

 

[Darter6]

Did they give you a final spec for caster and camber ? Meaning what they set them at.

 

[69SKCharger]

I do, but not on hand. Does anyone have the ideal settings that I could compare to?

 

[Cranky]

If it has too much toe in, that can also make it drive funny too. That was my last straw with present day alignment shops and learned how to do it myself. Also, are your front tires radials or bias ply? Bias ply tires will have a tendency to pull the car around on uneven surfaces.

 

[69SKCharger]

They are radials. I'll have to read up on alignments.

 

[Cranky]

In my cars, I like a lot of positive caster and negative camber and they drive/drove fine like that.

 

[Darter6]

I too do my own.In a perfect world I like a total of 1/8'' toe, Caster + 2 degrees (more if possible) Camber at 0 to -1/4 degrees. These old Mopars can be finicky and sometimes it is tough to get both left and right sides to balance out. You may have to compromise.

 

[Ernie ingling]

Hey have you tried adjust steering gear?

 

[69SKCharger]

Yes, i've adjusted the gear. Had it a little too tight and the steering wheel wouldn't return to straight on its own after a turn, loosened it up a touch from there and I think it's as good as it gets. Is there a center position in the box? I wonder if when adding the quick ratio Pittman arm whether I didn't position it properly in the center point of the steering box movement, or if that would matter?

 

[Darter6]

Yes, it has what is called High Point. best to check with the pitman disconnected cause it is kinda hard to feel. If you count turns from lock to lock,then split the difference you should find High Point. It's at that spot that you should adjust your steering gear slack.

 

[mopar 3 B]

If not done that why as you have found the steering can actually lock to one side and center came not be achieved when turning the steering shaft by hand.

 

[GMachineDartgt]

Yes, i've adjusted the gear. Had it a little too tight and the steering wheel wouldn't return to straight on its own after a turn, loosened it up a touch from there and I think it's as good as it gets. Is there a center position in the box? I wonder if when adding the quick ratio Pittman arm whether I didn't position it properly in the center point of the steering box movement, or if that would matter?

the factory service manual outlines the procedure to center the box. When centered, the master spline will be straight up. The pitman shaft and pitman ball joint will be in line front to back. The notch on the steering coupler will be visible on top as well.

Check the date codes on your tires and other slop in the steering linkage first.