1989 Ford Bronco Suspension - The Key to TTBPosted in Vehicle Reviews on November 19, 2004 Comment (0)
In 1980 the Bronco went from a straight Dana 44 front axle to what Ford calls the Twin Traction Beam front suspension. The TTB system is Ford's '80-'96 version of an independent front suspension. Mechanically, the TTB axle is similar to a straight axle. However, it uses a hinge in the middle. Think of a totally open pair of scissors and you have the idea. The inboard ends of the housings are attached to a frame-mounted crossmember, while the outboard ends support the steering knuckle and are attached to the frame through the springs and radius arms.
Our assignment was to learn all we could about Ford's Twin Traction Beam suspensions at fullsize truck specialist PG Series 4x4 in El Cajon, California. With the help of our connections at PG and at Tuff Country Suspensions and an '89 Ford Bronco, we gathered as many TTB installation tips as our greasy hands could grab.
Just a day after completing the lift install, we were out testing the capabilities and characteristics of the new suspension. With new 33-inch Mickey Thompson Baja Claws on M/T 16x10 Classic II wheels, the Bronco really stands out. For the first impressions see the sidebar "Night and Day Differences."
Night and Day Differences
Perceptions on the Newly Installed LiftSome argue that Ford never properly designed the TTB suspension. As a result, the fullsize Bronco has a loose, drastic body roll type of feeling. Riding in these rigs with the stock suspension makes you feel like you've been riding the waves all day. Tuff Country's Twin Traction Beam 4-inch system not only alleviated the excessive body roll but provided better articulation, more ground clearance, and a sharper turning radius. The truck feels drastically safer. Because of the soft polyurethane bushings, the suspension has surprisingly little suspension-related noise like annoying squeaking or creaking, and the brackets looked beefy and structurally safe. Here are a few more observations:
Tuff Country's radius arms work well because they employ rear pivot bushings that allow them to rotate throughout the motion of the suspension cycle. Because the arm is inside the bushing sleeve rather than mounted flush to the stock bracket, the suspension cycles farther and has less bushing wear. The design works with the bushing rather than against it. Additionally, the Tuff Country arms are 15 inches longer than stock and are made from reinforced steel tubing, which is a great deal stronger than the stock arms.
A rear leaf pack heightens and stiffens the rear. This is both good and bad. If the rear springs are too high, they distribute the weight to the front, causing the front end to bear more of the brunt of the vehicle's weight. This may prematurely wear front suspension components like the coils and the shocks. The good part is that the truck feels stiffer and sturdier, thus making the truck feel sure-footed on and off road.
The lift gives you the added benefits of having better clearance and better articulation without making the truck feel top heavy. The center of gravity remains stable and weight distribution top to bottom feels normal.
Note that you may want to modify your steering stops if aggressively treaded tires rub on the radius arms.
Some minor exhaust relocation may be needed if your exhaust comes in contact with your springs. Generally the rule is that while bolt-on kits are conveniently packaged and priced, they are not custom fabbed for your particular vehicle. Thus, the lift may require working out the fitment quirks of your kit.