Shock Therapy Race Rack & Pinion | Polaris RZR XP Shock Therapy

Shock Therapy Race Rack & Pinion for Polaris RZR XP

Please be aware that this steering rack is a race part and as such does NOT carry a warranty. Also, improper installation and/or maintenance may cause premature wear.

***CLEVIS’S CAN NOT BE INSTALLED INTO RACE RACK, CLEVIS NEEDS TO BE THREADED INTO TIE RODS. ****

Race Rack and Pinion RZR XP, This rack can not be used with stock tie rods. You must run an aftermarket set that uses 5/8 Rod Ends on each end. This race rack is designed for RACING. Race parts will wear out eventually and need to be rebuilt from time to time. Race parts have no warranty

After racing a “stock” rack and pinion in our shop XP Turbo with 32″ tires we just didn’t see any reason to change. We didn’t have any excessive wear or rattle in it even after 1500 race miles on the rack. But then, while leading our next race, BOOM, lost all steering and we were done! After a post race inspection we found that the factory rack had sheered in half right in the center of the splined rack gear allowing one half to shoot out the right and one half to shoot out the left side of the rack body.

No problem, we thought, just order an aftermarket replacement from anyone and it must be better right? Not so fast. The aftermarket replacements used rack gears that were barely .085 of an inch thicker at the same spot our rack had broken in two. Also, these racks spread the width of the tie rod pivots out as much as half of an inch. This is really bad. When you change the width of these pivot joints you add bump steer to your front end geometry. This means that as the suspension travels up and down the “Toe Setting” changes quite a bit toe in or toe out or both. This gives you nasty feed back in the steering wheel as you hit rocks or whoops which takes it’s toll on your arms and hands, of course but the real damage is to your front end joints, bushings, ball joints and bearings. The life of these parts are seriously cut short if your car has bump steer. Another major negative with bump steer is the car tries to constantly “hunt” for a direction to go. As the tires change Toe so does the direction of your car. When ever you hit a bump, whoop or jump and you hold the wheel straight, the car will search for a direction by shooting left or right on it’s own. This feeling is UN-nerving in a play car but down right dangerous in any race car. So our search continued for another rack and we found the only billet rack on the market. We bought it and loved the larger, square rack gear and custom tie rods but when we measured the width of the tie rod pivot points we found it was 1 1/2 inches too wide! This would create over 3 inches of bump steer? Wow, can’t run that. With no other choices of racks to buy we were forced to make our own Race rack and here is a list of the things we put into our Race rack that you won’t find in any other rack!

What Makes it the best?

• 7075 Aluminum construction – This high grade aluminum is almost as strong as carbon steel and costs 3 times as much as the more common 6000 series aluminum.
• Hard anodized plating – This hardened surface not only prevents wear in the harshest of environments but it also extends the life of the rack internally.
• Dispersed grease passage lubrication – Shock Therapy’s SINGLE grease fitting feeds 6 different spots in the rack through a network of internal passages. Proper lubrication is key to Rack life. Some of the spots the internal passages feed are the pinion gear, rack gear on all four sides and the vertical stress load spots where the rack gear sees the most potential wear. Tight internal tolerances make it so you will only need to grease this rack with two pumps of a grease gun every 1000 miles.
• Huge 1″x1″ square rack gear – This massive gear is twice as thick as the stock round gear which is the stock rack’s weakest point. The size of this gear prevents bending and breakage. The material used is also 125% stronger than the stock material. Another important thing about a square rack gear is that it prevents twist. The stock, round gear tends to twist in the rack body as the tie rods force it up and down. This twist wedges the rack gear into the pinion tooth which ultimately causes it to break.
• Pre heat treated rack gear – Most racks use a soft material for the rack gear making it easier to machine, then heat treat it often leaving larger tolerances or warps in the material. Shock Therapy stars with pre-hardened material that was perfectly straight then cut the gear teeth. This is a very expensive process, the tooling wears out fast and the machine time is 5 times longer. However, the end result is a perfectly straight gear with less than 1 thousandth of tolerance! This tolerance tightens up the rack body and removes any play in the rack, which reduces wear.
• Patented Gear Tooth Design – Shock Therapy has a patent pending tooth design that has TWICE the base thickness on the gear as a standard system does.
• Heat Treated Pinion Gear – Our pinion gear starts out as a solid billet of 4140 Chromoly. After machining their patented tooth pattern, the pinion is heat treated. Resulting in a material harder than a carbon steel drill bit for superior strength and longevity!
• Pinion Bearings – Shock Therapy created a new system where the pinion bearing is not pressed in but just barely slides into the rack body with just 1 thousandth of an inch of clearance. Then, our bearing retainer plate has a 10 thousandth step in it which pre loads the bearing vertically so it can’t move and can’t tighten up on the pinion gear this reduces rack function.
• Faster Steering Ratio – Shock Therapy’s Race Rack is a quick turn system. Fully extended it rotates the wheel just past 3/4 of a turn from center. This means that our rack has just over a 1.5 turn radius.
• High Quality Rod Ends – Our Race rack uses huge 5/8 rod ends for the tie rod pivots on the ends of the rack gear. Shock Therapy only uses the highest quality, Teflon lined, FK JMX10-T rod ends.
• “Taper Lock” Jam Nuts – Our Patent Pending rod end jam nuts, called “Taper Lock” are an industry first. The “Taper Lock” system that uses a machinist tool taper to lock the jam nut and rod end in place. As you tighten the jam nut, the male taper of the nut and the female taper of the rack gear seat together and lock. These jam nuts double up as the steering stops for the rack travel as well.
• 4130 Chromoly Clevises – The tie rod clevises are made from solid 4130 Chromoly and use high tolerance 5/8 diameter shoulder bolts to connect to the 5/8 rod ends in the rack. The WELD on clevises have two machined steps in them that are designed to insert into your tie rod tubing and weld on. The tubing diameters for the clevis are 1″ .120 wall tubing and 1 1/4 .095 wall tubing. Shock Therapy also offers a 5/8 threaded clevis that are designed to thread into your aftermarket tie rods or into a long travel kit. Lastly, they offer a longer clevis for Lone Star tie rods. Be sure to choose your clevis carefully so you get exactly what fits your tie rod system the best.