Bump Steering Issue

[bstandley1]

When I was getting my car aligned several weeks ago, the front end guy pointed out a "bump steer" issue. While the car was elevated, he compressed the front suspension and commented that the geometry of the front suspension was such that he couldn't remove the bump steer. As I recall, he stated there was a bump steer issue due to the tie rod / rack length. I've been reading up on the issue and looking over old postings on the club cobra site, but am kind of confused. Would any of you guys familiar with the issue enlighten me .... and can the problem be resolved easily? My car was manufactured in 1998 (serial number 9306)and I think it has the newer front suspension on it. Appreciate any of your insights.

Bob

[rdorman]

Bump steer can be practically removed from any suspension. It is done by moving the rack, lengthing or shortening the tie rod links and/or raising or lowering the tie rod end. I have yet to go through the excersise on my car yet. Although mine noticably toes-in in droop. Raising or lowering the rack or tie rod end will still result in the same radius, but it will move you to a different segment of the radius which may bring the steering in line with the arc made by the suspension movement. Changing lengths will increase or degree the radius and hence the ark. If it toes in (or out) both bump and droop, length will fix it, one in droop and the other in bump, moving things around will take care of it. Some times a combination of both. Some times you just have to make a compromise and pick the best option. The closer to zero, the happier it will be.

Well, at least off the top of my head;)

Rick

[bstandley1]

Rick,

Thanks for sharing your thoughts. Since the Northwest rainy season is upon us, I have several months to hash out a solution. Again, thanks for your help.

Bob

[rdorman]

No problem Bob. Good time of year to do it. It is a tedious process and may require some creativity. But is worth while. I would suspect that the new suspension should be designed with as little bump steer as possible. I don't know why any one would design other wise. A plate mounted to the wheel or spindle and a dial indicator works great. Heck even a laser pointer taped to the wheel will work. The amount is not so much important, get it as low as you can.

I will be interested in hearing the details.
Thanks
Rick