Fix It

The limited-slip differential found in the Ford 8.8-inch rear end is called "Traction-Lok." Locking the rear axles together and equally supplying power to both rear wheels improves traction. As the Mustang GT turns a corner the wheel on the outside of the turn must travel a greater distance, at a greater speed, than the wheel on the inside of the turn. The limited slip differential allows the connection between the two axles to slip and allow the outside wheel to go faster to make the turn smoothly.

Instructions

1

Park the Mustang GT on level ground. Secure the front wheels using wheel chocks. Kick the wheel chocks against the wheels using the heal of your foot so it cannot move while you are under it.

2

Raise and support the Mustang using a floor jack and jack stands. Position the floor jack under the Mustang GTs rear-end (differential) and lift the car until the rear wheels are off the ground. Position jack stands under the rear axles (tubes that connect the differential to the wheels) and lower the car onto the stands.

3

Place the transmission in neutral and release the parking brake. Turn the right rear wheel (by hand) and observe the left rear wheel. If the Mustang GT is equipped with "Traction-Lok" the left rear wheel will turn in the same direction and at the same speed as the right rear wheel. A properly operating limited-slip differential will cause the rear wheels to be difficult to turn by hand.

Traction bars are devices that keep the rear axle from "bouncing" on high-performance and specialty vehicles. They are most commonly associated with cars used for racing. Traction bars are also common on four-wheel-drive vehicles that are frequently used off-road. In many cases, such four-by-fours have traction bars installed at the factory as part of the original equipment, so the owner may not even know that his vehicle has them.

The Problem

Many high-performance cars and four-wheel-drive vehicles have leaf springs as part of the rear suspension. Leaf springs provide a more heavy-duty rear suspension than a coil spring can deliver. The leaf springs are attached, at front and rear, to the frame of the vehicle, and the axle is attached to the middle of the springs on both sides. This allows for some rotational give as the axle twists backward when providing forward thrust to the wheels. In hard acceleration, this twisting movement can become exaggerated and cause the drive wheels to start to hop up and down. The drive wheels lose traction and make a terrific clattering noise.

The Solution

Traction bars are heavy, rigid bars made of steel that bolt to the bottom of the springs or axle, or both. They extend to the front spring mounts on the frame of the vehicle. The brackets on both ends of the traction bars are pivoted, so as to avoid creating additional heavy stress points on the suspension. The design prevents wheel hop during hard acceleration in performance cars by preventing the axle from twisting backwards as it delivers forward thrust. Traction bars also help four-wheel-drive vehicles maintain traction in off-road maneuvers by preventing wheel bounce.

Installation

Though installation is simple for the experienced racing enthusiast, a professional shop can adjust them exactly to your car and perform tests to make sure they perform at a peak level. While most four-wheel-drive vehicles already have factory-installed traction bars, trucks that are used for utility purposes on farms and in rural areas can benefit by having traction bars installed.

Adverse Effects

On hot-rods that have reduced ground clearance, traction bars should always be professionally installed. The extra steel in the suspension and the reduced movement in the rear suspension can create serious ground clearance problems in vehicles that have minimal clearance to begin with. In any application, the addition of traction bars will stiffen the rear suspension and make for a less comfortable ride.