Rebuilding The Steering Rack - Steer Clear

Barry Kluczyk May 3, 2012 0 Comment(s)
View Full Gallery

Maintenance? Wear and tear? Random leaks? Tires?! You mean to tell me building and running a track day toy isn't just about dive bombing GT500s and getting point-byes from guys in overpriced "super cars?" Ugh, this sucks! Well, let's get the Killer up on the lift and find out just how much 500-plus miles of abuse has done. Yep, that steering rack is definitely leaking, and it feels disgusting too. I've been meaning to tell Greg that it wanders off center and takes an honest quarter-turn to start moving the wheels. Tie rod ends? Yep, they're shot too; one of them even has a hole in the boot and they both wiggle like crazy. Front tires look okay, although I think I can see metal in the rear ones, that can't be a good sign. Wheel bearings seem decent; we had just replaced them, although we should probably keep an eye on them. Last oil change? Well, I think that was after Sebring, or was it before? I don't remember, so yeah, we need another...

It goes like this, unfortunately, but it's not something we always get to talk about here in GM High-Tech. You see, we normally get to share all of the fun stuff, like adding big brakes, then we leave it be and neglect to mention the part about buying new rotors and pads every 6-months. But you know better, dear reader; you've been there for the real stuff, when your project car needs new wheel bearings instead of a camshaft, or a new set of tires instead of those fancy wheels you've been eyeballing. It's part of the game, whether you're daily driving your ride or putting together a weekend warrior. So this time, you get to see us in the grind, holding off on the big shiny new parts (okay, we snuck some in here too!) and instead installing some "not so fun" stuff that the STI Killer, our 2001 Camaro SS project, so desperately needs.

That part about the steering rack? That's all true. Truth be told, neither Greg Lovell nor I can remember where our existing steering rack came from (it was either the floor of his shop or on the car when we got it) and it not only leaked a significant amount of fluid – which was remarkable considering the fact that it felt as if it were filled with gravel instead of Royal Purple – but the stock tie rod ends were so bad you could literally give 20-degrees of steering input before it transmitted your request to the wheels. And it was a shame too, we've had this bum rack installed since day one and our modified Turn One power steering pump, the very pump responsible for keeping fluid cool and the juices flowing to the rack, hadn't really been put to good use supplying the leaking rock-crusher. So, it was a real pleasure this month to be able to send the rack to the very same company, Turn One, to have their in-house specialists rebuild our aging rack and turn it into a precision piece capable of turning our wheel inputs into wheel output with ease.

Speaking of wheel input, have you ever heard of bump steer? Technically speaking, bump steer is when the "spindles are steering to the left and right as the suspension goes up and down," or more specifically, "a change in toe angle caused by the suspension moving up or down. " Seems innocent enough, especially when you stop to understand that bump steer is "built into the geometry of the suspension and steering system, and has nothing to do with turning the steering wheel." But here's the catch..."the effect of bump steer is for the wheel to toe-in or toe-out when the suspension moves up or down. This toe change or 'steering' occurs any time the suspension moves, whether it is from body roll, brake dive or hitting a bump in the road. If the rate which the outer tie-rod arcs in or out does not match the rate the wheel moves in or out, the wheel will be turned by the tie-rod. This is bump steer." Of course, if bump steer is "built in" to the factory suspension, why bother to fix it? Well, when you lower a car – any car, be it road race, street, or drag – you change the wheel's "instant center," which is the center point of the arc that it travels. If you lower the car without also changing the arc of the tie-rod end (which is fixed from the factory), you can introduce bump steer, as we did when we dropped the Killer over 2.25-inches. Luckily, fixing bump steer is easy with the right parts, and a quick call to Summit Racing was all it took to get new "bump steer" specific tie rod ends on the way. Follow along to see how it's done and let's use this as a reminder to get out in your garage and fix those nagging issues you've been neglecting... a race can be won or lost depending how well you maintain your ride.

COMMENTS

TO TOP