Bump Steer Question?

Excuse my ignorance. Decreasing Bump Steer is important with respect to improving handling. Hotchkiss makes upper control arms and tie rod/sleeve kit. Now my questions. Is it the upper control arms or the tie rods/sleeves that actually do that??????? Is there any other aftermaket parts available that can do that???? Thanks ever

Both Hotchkis parts complement each other, I believe there is a benefit from the UCAs foremost and using their tie rods get both the tie rod and control arm angles just right.


No, I am not aware of anyone else that mentions bump steer correction for their aftermarket parts on these cars. I run Hotchkis parts on my car.

I am uncertain that bump steer causes any significant "problems" grip wise, other then the car wants to take a different path while the suspension vertically cycles thru a bump. as a driver that is always undesired/ a pain/distraction, etc, but not sure its a real issue at anything say below 7/10ths driving. Likely a subjective quality at modest levels.The normal corrective action/remedies changing the height relationship between the inner LCA pivot/outer lower ball joint, as it relates to the the inner and outer tie rod assembly. The change is normally is made by n adjusting the height of the outer TIE rod. It is doable, just not sure how close to perfect one needs to achieve (and perfect is not achievable in most cases).
Bump steeri s effectively a toe change thru vertical travel of the suspension

^ excellent reply

Yes it was. I wish I understood it.

Basically, as the suspension goes up and down, the tires will toe in and out to varying degrees.

In a handling situation, you have one side of the suspension going down, while one side goes up and this creates conflicting toe directions that aren't always exactly in line with the direction the car is pointed. This requires more or less steering wheel input from the driver creating a situation that may or may not feel like it has directional stability. It also creates scrub on the tires which adds heat which wears out the tread and can compromise grip.

There is a range of angles the fixed suspension parts (control arms) operate in that can complement or fight against the angles the movable suspension (steering linkage) operate in. Stock suspended Mopars will always have some degree of bump steer because the lower control arm pivot point is occupied by the torsion bar and the inner tie rod would prefer to be there, so it ends up being too low in its plane of operation. The alternative to correct this is typically to move the outer tie rod to put it in a better angle with the rest of the system.

While bump steer gets a lot of bad press, most drivers aren't capable of really noticing it unless the set up is really, really bad.

You always got to one up me.

If you know any Brand X folks that have lowered the front of a Fox car more than a half inch or so with shorter springs, and not either lowered the rack with offset bushings, or used tie rod ends with extended knuckle studs, ask to drive their car aggressively. You'll be treated to a setup described by Tony.

The devil made me do it.

Actually, after 20 years of my wife telling to explain things in simpler terms, I'd like to think I can somewhat do that.

bias ply tires can make bad bump steer a fun ride.

I have a road course Fox Mustang. Yes, it sux. Before I sorted it out, it was so bad that I couldn't really brake with the steering wheel turned. It would pull into the turn hard, then back out when released, and that's without the steering wheel pulling one way or the other, just bump steer turning the wheels. It had the offset rack bushings, too. When I measured the bump steer, it was 1/4" per tire, per inch of travel, so if the wheel moved up one inch, it toed out a quarter inch, per side. If you slammed on the brakes, and the nose dove an inch, that's a half inch of toe out. It it's rolling, one wheel's turning in, the other out. The readily available bump steer kits fixed it.

For our cars, shimming the steering box to move the pitman arm up or down fixes the left side, and slotting the idler arm so you can tilt it up or down does the right. You put a washer over the slot on the K-frame, then weld it in place where it needs to be to lock it in.

I always felt for the daily driver to experience bump steer was fairly easy. When at interstate speed, when on a curve entering or exiting the highway, if you encounter a pavement elevation change across the entire lane, like going from asphalt to a concrete bridge, if the car, with no steering inputs, wants to move a 1/2? lane over, and then after it settles down wants to move back, you got the proverbial "bump steer" example.

This is different then "skating'" across railroad tracks in that it wants to go back