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Swaybar Installation
By Matt Cramer

My Dart came with no shortage of handling problems, from wearing a cheap set of 175/80R13 tires to severely worn bushings. However, perhaps the most blatant, and most frightening, of its handling quirks is its tendency to lean hard when cornering. Claims of cars rolling hard enough to make the rocker panels scrape the pavement may be exaggerated, but this felt like a very real possibility when trying a hard turn.


With no sway bars, the Dart rolled like a boat when cornering.

Fortunately, excessive body roll is a fairly simple problem, both to understand and to fix. The problem comes from a suspension which does not have enough roll stiffness, a capacity to resist rolling from side to side. Although roll stiffness can be increased with stiffer springs, the most straightforward way to increase it is with a sway bar, sometimes called an anti-sway bar, anti-roll bar, or stabilizer bar. This device is a bent steel rod which connects to the suspension on both sides and the chassis in the middle, in such a way that the bar has very little effect when both wheels move in the same direction up or down, but twists when the body rolls, moving the wheels in opposite directions. This results in increased roll stiffness, without making the ride excessively harsh. However, the sway bars used as original equipment on many cars are often too soft, or sometimes, as in the case of the Dart, not even installed. The increase in roll stiffness can change the handling characteristics of a car. In general, a stiffer rear swaybar will reduce understeer or create oversteer, while a front swaybar might increase a car's tendency to understeer. However, on some cars, particularly those with independent front suspensions and solid rear axles, a front swaybar may reduce understeer. Often, rear wheel drive cars will benefit most from a front swaybar, while front wheel drive cars will benefit most from a rear swaybar. Often, running a rear swaybar on a rear wheel drive car with no front swaybar will result in a dangerous amount of oversteer. Whether or not a car will benefit from running a swaybar at each end depends on the car, and sometimes even on the individual preferences of the driver. A controversy exists as to whether Chrysler A-bodies, such as the Dodge Dart shown in this article, will handle best if a rear swaybar is installed, or should only use a bar on the front.


The entire kit from Addco.

The front swaybar kit featured in this article was built by Addco Industries, and comes in a kit complete with all parts needed to install it. This is a fairly heavy bar compared to those used on most production cars, 1 1/8" thick solid cadmium plated steel. It required about 4 hours to install, but could be installed in considerably less time if your car does not require drilling any mounting holes. The installation required a socket wrench set, penetrating oil, an electric drill and bits, a breaker bar, a screwdriver, and a set of ramps or jackstands.


Installation

The first thing which must be done is to push the rubber bushings onto the bar. These may seem to be too tight a fit over the flattened ends of the swaybar, but it's possible to slip them over the ends using a screwdriver and enough force. If you have to use a lubricant, which was not required in this installation, use water, not grease. Some swaybar kits come with polyurethane, not rubber, bushings. Since polyurethane is harder than rubber, these bushings are typically slotted, making for an easy and straightforward installation. And unlike rubber bushings, polyurethane ones are more grease tolerant.


Sliding the bushing onto the bar using a screwdriver.

Assembling the end-links is relatively straightforward. This is best done before attempting to install the bar. The Nylock nuts should not be tightened at this point; just make sure that the end-links will not fall apart while assembling the swaybar under the car. Avoid the temptation to mount the angle bracket to the shock mount and then assemble the end-link. It's easier to get the angle bracket on without the assembled end-link, but trying to assemble the end-link to a bracket mounted on the car already is more trouble than it's worth.


The end link as assembled.

Now, it's time to get under the car. For best results, place the car on a flat surface and support the front end on a pair of ramps. Supporting it by the wheels makes it less likely that the swaybar will be pre-loaded, which can decrease a car's ability to turn in one direction while improving cornering in the opposite direction. However, if you don't have a set of ramps, a pair of jackstands will do. This should go without saying, but don't even think of getting under the car if you're only supporting it with a bumper or scissor jack.


The Dart sitting on a pair of ramps.

The angle brackets on the end-links mount to the shock absorber studs. Some Chryslers came with factory swaybars which attach to special connecting points on the lower control arms, but cars without a swaybar often used different lower control arms which lacked these mounting points. Since the Addco bar was designed to fit cars whether they originally had a swaybar or not, it mounts to the shock absorber stud to avoid drilling holes in the lower control arms. The end-links hang to the outside of the strut rods.


The end link as installed on the car.

A brace connecting the radiator support to the K-member is apparently intended to provide additional protection in a crash, but it gets in the way when installing the swaybar. It simply unbolts. The directions allege that it can be re-attached after installing the swaybar, but in the case of this Dart, the bar could not be raised high enough to clear the brace. The brace was never re-attached, and removing it is unlikely to provide any increase in chassis flex. So if you can't get the link back on, don't worry about it.


That troublesome brace.

Bolt together the swaybar mounting brackets over the bushings, and raise the bar to the K-frame to determine where to mount the angle brackets. If there are any holes in the K-member, these should be used to mount the points, but on my Dart (as well as many other early A-bodies), no such holes were to be found. If there aren't any convenient holes, locate a suitable spot and drill them. The exact location of the bushings is not critical, but it should be symmetric, with the bushings moved as far out as possible while remaining on the straight center section of the bar. There are also a few internal ribs in the K-member where the beams intersect, which must be avoided when drilling the holes. Bolt the brackets to the K-member.


Drilling the holes to install the brackets.

Ensure that the swaybar is centered, then tighten down all fasteners holding it in place, particularly the end-links. If possible, re-install the radiator support brace at this point. The swaybar is now installed, and ready for a road test.


The bracket bolts to the K-member.


On the road

The effects of the swaybar are quite noticeable. The Dart's body roll is now a fraction of what it once was, resulting in a soft handling which seems to be more reminiscent of a large luxury car than anything else. The stiffening of the suspension does not appear to increase ride harshness, although there are some noticeable creaks on rough pavement which weren't there before. A probable cause is the way the bushings are mounted using angle brackets, instead of bolted directly to the K-member. The bushing brackets created another problem, largely due to the use of angle brackets to attach a set of universal bushing blocks. The tips of the brackets hit the pavement on a very deep dip in the road shortly after installation, and will have to be hammered back into shape, or replaced with modified bushing mounts attached to the bottom and front of the K-frame with no angle iron. Stiffer torsion bars (installed after this article was written) might help avoid bottoming out, as would watching where I'm going a bit more closely.


The sway bar is completely installed on the Dart. Notice that the brackets hang below the rest of the subframe, reducing ground clearance noticably.

For a single modification, the improvement in handling has been tremendous. Not surprisingly, it also serves to highlight some of the car's other shortcomings. There is a significant amount of understeer, which we will treat by balancing the increased front roll stiffness with a rear swaybar. Furthermore, the 80-series tires contribute a fair amount of mushiness of their own to the handling, which will also be remedied soon. Another problem discovered while working on the front suspension is the toll that nearly 200,000 miles have taken on the bushings. While a swaybar will quickly scratch an itch for better handling, this is only the beginning. Future articles on this site will document other mods installed on the Dart, including replacing the rubber bushings with polyurethane, converting it to disc brakes, and installing heavy duty torsion bars.

-Matt Cramer (aka MadScientistMatt)



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