FRONT SUSPENSION UPGRADE WITH QA1 CONTROL ARMS, ADJUSTERS, AND DYNAMIC STRUT BARS
Front suspension upgrade with QA1 control arms, adjusters, and dynamic strut bars.
During the preseason annual inspection of our ’69 Dodge Dart, we noticed that both of the lower control arm bushings were torn. The drag race season was approaching rapidly, and, as a result, our repair options were quickly contemplated. One thought was the control arms could be rebuilt for a third time (the second time in the author’s 29 years of ownership), but that consideration promptly departed as rebuilding nearly 50-year-old control arms seemed like an unattractive option. A second, and more attractive, option was to replace the lower control arms.
Two years previous, when the factory upper control arms had become worn beyond repair, a pair of QA1 tubular upper control arms (PN 52301) and eccentric camber bolt adjusters (PN 52361) were installed in place of the factory control arms. The quality of construction of the QA1 control arms was exceptional, and because of our satisfaction with the construction and performance of the upper control arms, QA1 was contacted for a pair of matching tubular lower control arms (PN 52307), torsion bar adjusters (PN 52360), and dynamic strut bars (strut rods) (PN 52311).
Although the focus for the Dart was front end suspension components, for the last 25 years, QA1 has specialized in performance shock absorbers, carbon-fiber driveshafts, rod ends, front and rear suspension, spherical bearings, and ball joints. QA1 provides related items to a variety of markets including: circle track racing, drag racing, street performance, street rodding, construction, fitness, agriculture and packaging equipment, as well as several other industrial markets.
Before the parts swapping started, some rough front end measurements of the Dart’s camber (tilting of the top of the wheels from the vertical; when tilt is outward, camber is positive), caster (tilting of the steering axis forward or backward to provide directional steering stability), and toe-in (the amount, in inches or millimeters, that the front of the wheels point inward) were performed. These measurements would be the baseline when the new parts were installed. Getting the adjustments as close to the baseline during the installation meant less work would have to be performed at the time of the alignment on the Dart. The camber measurements on the Dart were: left front (LF) (-0.25 degree) and right front (RF) (-0.40 degree), caster was: LF (3.00 degrees) and RF (3.25 degrees), and the toe-in was 1/32 inch total. The ride height of the Dart was also measured. With all the vehicle weight on the four tires, either on the ground or on a drive-on lift, and the suspension jounced several times, a measurement from the floor to the wheel lip opening on the centerline of the spindle or axle at all four corners of the Dart was made. Additionally, the torsion bar anchor point heights were measured to the ground. All the measurements were noted for future reference, so the ride height could be
re-established after the installation of the QA1 components.
With all the measurements completed, the Dart was moved to a two-post lift. The parts replacement could’ve been performed on jackstands, but we had an opportunity to use the lift, and it’s always nicer to work on a car while standing. To remove the lower control arms and strut rods, we referred to our factory shop manual. Starting on the RF of the Dart, the wheel was removed and then the lower shock bolt. The shock was compressed to provide additional clearance to other suspension components and remained suspended by the upper shock bushings and nut. If the Dart had still been equipped with the factory disc or drum brakes, the disc brake assembly and the splash shield or the drum brake assembly would have to be removed to gain access to the lower ball joint, but the Dart was fitted with Wilwood front disc brakes, consequently this step was not necessary. If a sway bar had been on the Dart, the end link would have been removed. Moving to the strut rod, the roll pin (cotter pin) was driven out followed by the removal of the nut, retainer, and front bushing with the sleeve from the forward end of the strut. The depth of the torsion bar anchor bolt into the lower control arm was measured, and while unwinding the torsion bar anchor bolt, a count of the rotations of the bolt was recorded for the reinstallation. The ball joint nut was loosened, and a pickle fork and hammer were used to break the control arm free from the ball joint. The ball joint nut was removed, and the lower control arm shaft nut was unthreaded. The torsion bar clip was freed from its retainer groove, and the torsion bar was slipped from the control arm. The control arm along with the strut rod assembly was removed from the Dart.
Once the control arm and strut rod were out of the Dart, the strut rod was separated from the control arm. The length of the factory strut rod was determined by measuring the distance between the mounting shoulder on the strut rod at the lower control arm and the bushing that contacted the K-frame near the radiator support. This measured length was transferred to the new adjustable QA1 dynamic strut bar. Two jamb nuts (one on each end of the bar) were tightened to guarantee the length would remain stable during the installation and during the usage of the Dart in the future.
The assembly of the RF of the Dart was straight forward. The QA1 lower control arm with the dynamic strut bar loosely connected slid into place at the two factory mounting points on the K-frame. The supplied washer and nut were lightly threaded onto the control arm shaft, and a washer and bolt were run through the K-frame at the radiator
support area to attach the dynamic strut bar. The rod end of the dynamic strut bar was adjusted to line up perpendicular with the floor, and the lower control arm was moved through its entire range of motion to confirm the rod end would not bind at any point of the movement. If binding had occurred, the rod end would have been rotated until a bind-free movement of the lower control arm was achieved. Once the range of motion was established, the lower control arm nut, and the dynamic strut bar fasteners were snugged to minimize the play during the reassembly. The lower ball joint was pushed through the lower control arm, and the lower ball joint castle nut was properly torqued. A cotter pin slid through the ball joint stud and castle nut. After the lower ball joint was installed, the torsion bar was pushed into the lower control arm and the torsion bar clip was reinstalled. The new QA1 torsion bar adjuster was placed in the lower control arm, the bolt lubed with a generous coating of antiseize, and the bolt was threaded into the lower control arm torsion bar adjuster. An attempt was made to achieve a similar ride height to our baseline, accordingly the adjuster bolt was twisted as necessary to achieve the preinstallation measurements. With the installation finishing up on the RF, we pulled the shock absorber back into place, slipped the bolt through the lower control arm shock mount and the absorber, and we tightened the bolt. The RF suspension was now reassembled. We moved to the LF of the Dart and repeated the previously described steps. Upon completion of the LF, the Dart was lowered onto its tires and was jounced several times to settle the suspension. A few quick height measurements were made and compared to the baseline measurements. It was determined the torsion bar adjuster bolts needed to be twisted a few turns to reestablish the proper ride height. With the wheels and tires supporting the Dart’s weight, the dynamic strut bars and the lower control arm fasteners were torqued to the recommendations of QA1.
Satisfied with the installation of the QA1 suspension components, the Dart was loaded on to a trailer and transported to Pennsylvania College of Technology (Penn College) to have the alignment performed. Penn College has the latest Hunter Alignment machines and equipment, hence it was a perfect platform for the performance alignment. Once at the college, the required procedures to establish the Dart’s alignment angles were performed, and based upon the computer readout, some adjustments were required. The dynamic strut bars were shortened 1/8 inch (a slight change of caster), and the ride height was readjusted. The procedures to determine the alignment angles were repeated. The upper control arm eccentrics were adjusted to provide camber measurements of: LF (-0.20 degree) and RF (-0.30 degree) and caster measurements of: LF (4.6 degrees) and RF (4.3 degrees). The toe adjuster sleeves were rotated to confirm a toe-in of 1/32 inch. After all the adjustments were completed, the ride height was checked for the last time, and all of the fasteners that had been loosened or removed during the QA1 suspension component swap were final checked for proper torque.
The decision to install the QA1 parts on the Dart was the correct choice. Unless an enthusiast’s ride is a quality restoration, why rebuild 50-plus-year-old components when QA1 provides quality aftermarket products? If the plan of a Mopar aficionado is to run their ride on the street or, better yet, run their ride hard at the track, QA1 parts will provide piece of mind when the owner’s safety is on the line. In our case, with the new QA1 parts installed, the Dart has increased front-end travel, the lower control arms and dynamic strut bars are a slightly lighter weight compared to the factory parts, the components fit perfectly, and the QA1 components look great. Is it time to update your Mopar? Get in touch with QA1 to see what they can do to bring your Mopar into the 21st century.
Before the QA1 components were installed onto the Dart, we made a few measurements. These measurements would be our target when we reassembled the suspension. Luckily, we had an alignment bubble gauge, which allowed us to measure the camber angle of each front wheel. With turn tables under the front (and rear) tires, we were able to perform caster sweeps (as seen here) of the front suspension to acquire the caster angle at each front wheel. We noted the camber and caster measurements for later review.
An additional ride height measurement was made from each torsion bar anchor point to the ground. These two measurements plus the wheel opening measurements assured us that we could return the Dart to the baseline ride height after all the assembly was completed. During the reassembly of the suspension, fine-tuning the torsion bar adjusters would allow us to attain the baseline settings.
QA1 supplied a pair of dynamic strut bars (PN 52311), a pair of tubular lower control arms (PN 52307), and a pair of torsion bar adjusters (PN 52360). The lower control arms have provisions for sway bar endlinks, but our ’69 Dodge Dart does not have a sway bar. The dynamic strut bars can be adjusted to fine tune the vehicle’s alignment.
We measured the vehicle at each wheel opening to establish a baseline ride height. The measurement was taken from the floor to the fender opening while lined up with the centerline of the spindle or axle. Again, we recorded our findings for later use.
The last baseline measurement we made was the toe measurement. An old mechanical toe bar was used to measure the distance between the front of each front tire (measured 8 inches off the ground at a tread bar on the tire) and measure the distance between the same two tread bars on the back of each front tire. The use of the toe bar made the measurements easier to attain when compared to using a string.