Bump Steer on 68 Camaro

[jonny51]

Definition: The tendency of a vehicle to suddenly veer or swerve to one side when hitting a bump or dip in the road. The condition is caused by uneven toe changes that occur as a result of the steering linkage or rack not being parallel with the road surface. This causes the wheels to change toe unevenly as the suspension undergoes jounce and rebound.



Got that from another website
Also try this link http://www.modularpower.com/bumpsteer.html

[Marcus SC&C]

Try to visualize (from the front or rear) the spindle swinging in a vertical arc as the suspension moves through it`s range of travel. Now notice that the steering arm is swinging with it,in the same arc. Now picture the tie rod,bolted on the center link but with the outter tie rod end free. Picture it swinging in an arc the same height as the spindle`s. 99 times out of 100 these two curves will not be the same due to the heights or lengths of the parts being off (most of the time both). So,when you bolt the tie rod end to the steering arm the tie rod end ends up either pushing or pulling on the steering arms,steering the car with no steering input from the driver. Virtually all production cars have some bumpsteer and many older ones have a LOT. In the case of early Camaros the tie rod lengths are off some and the outter tie rod end is "around" 1/2" too high. I say "around" because it varies with alignment (especially caster),ride height and variations in different versions of steering parts and arms used on 1st gens. 1/2" of correction gets it in the ballpark though. Remember bumpsteer is MUCH more sensitive to vertical changes than horizontal (length) ones. In some cars the ratios can be as high as 1/8"V=3"H! That`s because the length of the parts dictates the shape of the arc but the vertical effects where in the arc a component is at a given time. Get the arcs so they match exactly at ride height and they`ll deviate from each other very little in the usable range of travel. If they`re in totally different locations at ride height,you`ve got problems! Without putting a bumpsteer gauge on a given car you`re not going to know *exactly* how much things need to be moved but many factory cars are so far off you can make great strides in the right direction pretty easily and really improve the way the car drives. We sell tall stud modular tie rod ends for early Camaros that drop the pickup point and get those arcs much closer together and reduce the bumpsteer to the point it`s no longer noticable. I hope this makes a little more sense of bumpsteer rather that confusing you more. Marcus

[chicane]

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