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Rebuilding The Steering Rack - Steer ClearFrom the August, 2012 issue of GM High-Tech Performance By Barry Kluczyk Photography by The Authors
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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.  1 That’s not engine oil,...  1 That’s not engine oil, it’s power steering fluid, and it’s not only coating the K-member, it’s all over the place under here. Besides leaking like a sieve, our stock steering rack felt horrible and had a dead spot straight up, which was unnerving at speed, to say the least. As a vital piece of driver input/output and a major factor in getting around a track safely, it was time to get serious and replace our junk unit with something fit for the Killer.  2 Removal of the steering...  2 Removal of the steering rack starts here, at the power steering line connections. An 18mm open end wrench is all you need, along with a bucket or drain pan to catch the power steering fluid as it escapes. No need to worry about those smaller lines on the left, they can stay snug to the rack for now.  3 Greg Lovell of AntiVenom...  3 Greg Lovell of AntiVenom (you should know who he is by now) shows us the easy way to remove tie rod ends, using a quick blow to the spindle to free the stock pieces. If you’re only swapping ends, make note of their placement, as it will save you time during the new install. In our case, we needed everything re-done, so Greg simply removed them from the spindle and dumped them in the trash.  4 This can go one of two...  4 This can go one of two ways. One: you get lucky and both of the steering rack to K-member bolts slide in from the bottom, making for a quick and easy removal. Two: the driver’s side bolt (shown here) is installed upside down (bolt on top, nut on the bottom) and you have to loosen the K-member and/or jack up the motor to make room to slide it out. We’ve seen them go in both ways from the factory, so plan ahead if you’re going to tackle this project yourself.  5 Last but not least, remove...  5 Last but not least, remove the steering shaft from the rack, slide it out of the way, and pull the unit out from under the K-member. If both bolts have been removed, along with the factory tie-rod ends, you shouldn’t have any trouble getting the rack out of the chassis. If you’re going to have it rebuilt, box it up and ship the entire unit to Turn One for a quick and easy upgrade.  6 After receiving the grimy...  6 After receiving the grimy original rack assembly, Turn One begins the rejuvenation process by completely disassembling it and cleaning the hard parts – which can be a real mess if bad seals allowed fluid to leak into the tie rod boots. Regardless, the original seals are discarded and later replaced by new ones. Here, the cleaned rack housing is ready to be rebuilt.  7 The process gets started...  7 The process gets started with pressing the pinion bearing into the housing. Like many of the other original components, the factory pinion bearing is a strong part that typically requires only cleaning and repacking prior to reinstallation.  8 Next, the new rack seal...  8 Next, the new rack seal is slipped over the rack, using paper to cover the rack’s teeth as the seal slips over them to prevent snagging the pliable seal. Any nicks or cuts in the seal could become a leak source.  9 A liberal dollop of chassis...  9 A liberal dollop of chassis grease is slathered on the rack teeth and, because the bearing rides all around the shaft, the backside as well.  10 The greased rack then...  10 The greased rack then slides into the housing, followed by O-ring-sealed bulkheads.  11 With the rack in place,...  11 With the rack in place, measurements are taken at both ends to ensure it is centered in the housing.  12 The pinion/valve assembly...  12 The pinion/valve assembly comes next and is prepared with the same chassis grease as the rack shaft—as well as a quartet of Teflon seals—then pushed into the housing to mesh with the rack teeth.  13 To ensure a feature called...  13 To ensure a feature called the “whistle notch” is aligned perfectly, the pinion’s mesh on the rack must be perfect. If it’s off by even a single tooth, the pinion must be removed and reinstalled. The alignment is confirmed by checking again whether the rack is centered. If it’s not, the alignment is off.  14 With the pinion installed,...  14 With the pinion installed, a bearing and spring are installed on top of it and held in place with an adjustable retaining cap. When the cap is installed, alignment marks are made on it and the housing, and then the cap is turned 60 degrees to set the correct preload on the bearing.  15 The fully assembled rack-and-pinion...  15 The fully assembled rack-and-pinion assembly is dyno-tested at Turn One. The tests include basic leak checks at the seals, a pressurized test for internal leaks and a “pressure effort” test on the valve, which involves “turning” the rack back and forth. It all ensures the rebuilt rack performs as good as new.  16 After the test session,...  16 After the test session, the original inner tie rods, boots and tie rod ends are re-installed, completing the rebuild process. Of course, we’re not planning to reuse the factory (junk) tie rod ends, but if yours were still in good condition, Turn One’s got you covered with the installation.  17 For roughly $200, the...  17 For roughly $200, the original steering rack was revived to like-new condition. A brand-new unit, with core charge, will cost about $100 more, so Turn One’s solution is a good value. There’s also the assurance that an expert technician rebuilt it by hand—and that counts for a lot, too.  18 High quality and good...  18 High quality and good looks aside, Turn One also boasts incredible customer service, and the turn around on our rack was less then two weeks, shipping time included! In this industry, for a hand-assembled product, that’s fast and for racers on a time crunch, it’s service that’s hard to beat. Greg is fast too, and had the rack back in before we could even snap a picture!  19 On the right, you can...  19 On the right, you can see the sorry shape that our factory tie rod end was in. The boot was ripped and you could almost feel the crunch from inside the car. Additionally, our “drop it in the weeds” stance really messed with the stock “instant center” of our wheel, which could introduce bump steer into the suspension if not properly addressed. Luckily, fixing bump steer is as simple as installing a proper set of bump steer specific tie rod ends, like the Baer units you see here (PN BAE-3301011), which we ordered from Summit Racing.  20 For 165-bucks, Summit...  20 For 165-bucks, Summit Racing shipped these aluminum beauties right to our door and they will replace our sloppy factory style tie rod ends for a more precise feel, along with improved bump steer control. By simply adjusting the length of the tie rod end pin (using those included spacers you see above and below the tie rod pin) we will be able to compensate for our new ride height and geometry changes, which will quell bump steer and keep us pointed in the right direction, no matter what the front wheels are doing.  21 Installing the tie rod...  21 Installing the tie rod end is fairly straightforward, although adjusting the system does take a keen eye and a trained technician. Like the factory unit, the tie rod end itself simply threads onto the steering rack, while the pin installs into the spindle with a nylon locking-nut. Notice that the Bear units don’t use a cotter pin, so make sure the pin is tight to the spindle before heading out on track.  22 Before Greg could go any...  22 Before Greg could go any further, we had to locate the tie rod end on the rack for steering wheel alignment. With the steering wheel straight, Greg adjusted the location of the tie rod end, making sure it was even on both sides and that total toe in (both side-to-side and total) was within spec for our application.  23 Installed at the “factory...  23 Installed at the “factory height” you can see how dramatic the angle of the steering rack to the spindle really is. This change from factory is what induces additional bump steer. As the front suspension compresses, the tie rod end will be pushed upwards, and at this angle, will easily pull the spindle inwards, causing a change in toe and unwanted steering feedback.  24 Adjusting bump steer requires...  24 Adjusting bump steer requires a significant amount of trial and error, as small changes in the tie rod ends’ location (via spacers), can result in major changes to output. To adjust, Greg checked the wheels’ toe at rest, then compressed the suspension and checked it again. The change in toe-in (or toe-out) was noted and then the tie rod ends’ location was adjusted. Note, we’re not on an alignment rack here and you can easily do this at home if you have the right tools and enough patience.  25 Eventually we ended up...  25 Eventually we ended up with the Summit Racing supplied tie rod end in the lowest location, which gave us the least amount of toe change throughout the suspension travel. Depending on your setup, you’re probably going to need a different position, so make sure you verify the location of the tie rod end on your own. If you’re not comfortable doing these adjustments at home, don’t worry, any good alignment shop should be able to take care of it, just make sure they understand and can properly explain bump steer before you drop your pride and joy off for the work!
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1999 Pontiac Firebird Trans Am - Street Heat
Almost no other GM model pulls off the aggressive look quite like the fourth-gen Trans Am, and when you modify one like Nathan Turjillo from Las Vegas has, well; you end up with a real showstopper....
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