Bump Steer: What Is It And How Do You Fix It?
If you’ve ever driven an older car you’ve most likely experienced some level of bump steer. Simply put, bump steer is when the toe changes during the suspension’s range of motion. This means that while cruising down the highway or hitting a back road the toe is constantly changing as you’re driving which can cause unpredictable turns or jolts. We spoke with Baer Brakes and they taught us how to fix bump steer on our 1966 Chevelle Project No Name.
Why do classic cars have bump steer? That’s a bit of a two fold answer. The first is back in the 60’s and 70’s these cars weren’t performing nearly to the level we expect them to nowadays. Cruising down the highway meant going 55MPH, not 80MPH with the A/C on. The engineering and dimensions weren’t as precise as today and that was acceptable.
The second and probably more important reason why a classic car has bump steer is the tires. Back when they were new, they had bias ply tires. Bias ply tires like a lot of negative caster, where the upper ball joint is in front of the lower ball joint. With modern radial tires that perform so much better, they like positive caster with the upper ball joint behind the lower ball joint. Now you may be asking yourself, what does the suspension geometry have to do with bump steer?
The simple answer is that by installing aftermarket suspension that fixes the caster on these old cars, it rotates the spindle. On this Chevelle for example, it’s rotating it so the steering arm on the spindle is going up, away from the ground. Even though this might only be a half inch or inch or less, it’s enough that now the steering arms aren’t the right length and cause bump steer. The solution from Baer Brakes fixes that.
Baer Brakes bump steer arms replace the outer tie rods with a rod end joint. This rod end will provide much more precise steering to start with. The beauty of the system is that you can adjust this new arm down back towards it’s original position or even closer to the ground to almost completely eliminate bump steer. More precise steering and elimination of bump steer – a win-win in our book! On top of that, these new Baer Trackers are ultra-beefy, much stronger than the factory tie rod adjusters and they just look way cool under the car.
While we are making all sorts of other upgrades to this car to make it drive and handle better, we decided to go ahead and install this bump steer kit from Baer Brakes. Installation is really simple and to do both sides only takes a few hours at the most.
We started by jacking up the front of the car and removing the wheels to have more access. Then we removed the cotter pin on the outer tie rod castle nut then removed the castle nut. Using a hammer we popped the tie rod out of the spindle. From here we removed the outer tie rod and tie rod sleeve.
To install the Baer Trackers, we threaded the new jamb nut onto the inner tie rod. Then we installed the new outer bolt that goes into the spindle and attaches to the rod end. From here we threaded the new Tracker assembly onto the inner tie rods until the rod end lined up with the bolt going through the spindle. One thing to note is that we made sure not to move the spindle during this process so that our alignment will stay as close as possible. We will still need to get a proper alignment, but this will help it remain close.
Since this car has updated suspension and has been lowered, we knew the spindle we rotated quite a bit back. Using the supplied spacers we bumped the Tracker arm down a bit as a bit of a ball-park to where it should be. One way to help get it close to line it up with your lower control arm so they are parallel.
Our last step was to run the jamb nut down and tighten all nuts then re-install the wheels. Right now the car is still engine-less but we can’t wait to hit the road with it and see the difference these Baer Trackers will make! We could definitely feel the bump steer before while cruising – not anymore though!
It’s highly recommended to take your car to a proper alignment shop after installation for alignment. Not only do they need to know how to adjust toe but then will need to cycle the suspension to measure and use the correct spacers to completely eliminate bump steer. That’s the next thing on our list!
For more information or to order up a set of Baer Trackers for your ride, hop on www.Baer.com or give them a call at (602) 233-1411