ShopTalk: Holding Steady

Sep 1, 2011

In the suspension world, most of the talk is about springs and shocks, leaving out the equally important sway bar (also called an anti-roll bar or ARB). While springs and shocks support the vehicle and prevent vibrations and bumps from traveling from the road to the vehicle’s occupants, a sway bar increases rider comfort and vehicle handling by decreasing body roll.

In its most basic form, a sway bar is a metal “U” attached to both the frame and the axle (or suspension arms, depending on the vehicle) on each side. As the body and frame start to roll during a turn, it must twist the sway bar, which creates a torsional force resisting the lean.

Sway bars can be used to improve both handling and feel on everything from a classic muscle car to a dump truck, but in this install article we used a Hellwig Products rear sway bar (part number 7893) on a 2003 Ford F250 with a 6″ lift. The kit includes everything needed and the installation only requires basic hand tools. And because other manufacturers offer their own sway bar products, it’s always recommended that installers follow manufacturers’ directions and contact them with any questions.

The Hellwig bar we used is made from heavy-duty 1-1/4″-diameter, heat-treated, 4140 spring steel, which is stiffer and stronger than the factory bar. This kit’s sway bar has a three-hole design allowing the driver to tune the sway bar’s stiffness to the individual driving style, and adjustable end links that allow the bar to work with different-height vehicles

The difference on the truck with the new sway bar installed is noticeable and improves the driving experience in everyday driving or when carrying a large load in the bed.

Step 1>>: Remove the factory rear sway bar by unbolting the end links at the frame and the U-plates from the axle. It is not necessary to keep any of the original equipment, as all new parts are provided.

Step 2>>: Locate the saddle brackets on the cast differential housing.

>>Step 3: Insert the U-bolts around the back of the differential housing and through the saddle brackets.

>>Step 4: Using the provided grease, lubricate the inside of the D-shaped bushings and press them onto the straight areas of the sway bar on each side of the center hump.

>>Step 5: Place the U-plates over the bushings.

>>Step 6: For a stock-height truck, it is recommended to disconnect this emergency brake cable bracket while the sway bar is being attached, in order to allow the emergency brake cable to run underneath the sway bar arm. On our F250 with its 6″ lift, we found it worked better to leave the bracket in place and run the cable above the sway bar arm.

>>Step 7: If the emergency brake cable bracket is going to be disconnected, it is attached to the shock mount with one bolt, which is easily removed. The bracket is on the passenger side of the vehicle.

>>Step 8: Place the sway bar hump over the differential, and line up the U-plates on the saddle brackets.

>>Step 9: Use the provided washers and stover locknuts to attach the U-plates and sway bar to the saddle brackets. Leave the assembly loose at this time for later adjustment.

>>Step 10: Now we start assembly of the end links. Using the included grease, lubricate the outside of the hourglass bushings and firmly push them into the end link loops. The hourglass bushing with the 5/8″ hole goes on the frame side of the end link, and the hourglass bushing with the 3/4″ hole goes on the sway bar side of the end link.

>>Step 11: Lubricate the outside of the sleeves and tap them into the correct hourglass bushings using a hammer.

>>Step 12: Thread the included 9/16″ nuts onto the end links and then thread together the two pieces. The exact length of the end links will be adjusted later.

>>Step 13: Using the existing hole from the factory end link and the included ½” x 2-1/2″ bolt, washers and locknut, attach the end link to the frame. Torque the 1/2″ bolt to 60-70 ft.-lbs.

>>Step 14: Slide the sway bar in the frame bushings until the hump is centered over the differential housing and then rotate it up and down to make sure there is adequate clearance between all suspension parts and any wires or hoses. Once it is confirmed that the bar is centered and has plenty of clearance, torque the stover locknuts on the U-bolts to 60 ft.-lbs.

>>Step 15: Lift the sway bar so the arm is parallel to the ground. The closer the arm is to parallel, the better the sway bar will perform.

>>Step 16: The sway bar has three holes in the arm for adjustability. It is recommended to install the end link in the hole farthest from the axle until the driver becomes familiar with the new handling characteristics of their vehicle. The driver can later tune the bar to his or her driving style by attaching the end link to the inner holes to increase stiffness.

>>Step 17: Adjust the length of the end links until it reaches the sway bar, and attach the end links to the sway bar using the included 7/16″ x 2-3/4″ bolts, washers and locknuts. Torque the 7/16″ nuts to 35-45 ft.-lbs.

>>Step 18: Tighten the 9/16″ adjustment nuts on the end links to 70 ft.-lbs. to keep the end links at their current length. If you chose to disconnect the emergency brake cable bracket, re-attach it now, as well.

>>Step 19: The install is now finished. It is recommended to bounce the vehicle, take it on a test drive and then recheck all clearances and torques to make sure there is no slipping or interferences. Now enjoy the decreased body roll and improved handling on your vehicle.

Ben Knaus is product development engineer for Hellwig Products.