POL744 Poly Bushing Kit

SellercoreSellercore

Sellercore

 Passat

1998-2003

 Passat 4 motion

1999-2003

WHY POLY?

Polyurethane is unaffected by petroleum-based solvents and atmospheric contaminants. It can also be formulated in different degrees of hardness (durometer), ranging from the gloppy consistency of the children's toy known as "Green Slime" to the solid density of a bowling ball. Between these extremes lies the perfect formula for suspension-bushing material. When formulated and designed correctly, polyurethane bushings will be the last bushings you put on the vehicle.

Rubber deterioration also compounds the original vacillation of the suspension. Rubber bushings do not rotate; they simply twist to allow movement. This works to a certain degree when the rubber is new. As it starts to age, the ability to rebound back to the original shape diminishes. This translates to steering deflection. Deflection causes changes in camber, caster, and toe angles, influencing steering control.

Another shortcoming of rubber is its displacement under load. The result is vague handling. When a vehicle initiates a turn, the load placed on the suspension components is considerable. In fact, deflection of the rubber requires some of the bushings do the job of the suspension components they adjoin. Performance polyurethane bushings do not crush like rubber. They allow movement of suspension components through rotational sliding. A firm, crisp, and responsive suspension is the result.

BMW vehicles utilizing polyurethane bushings can benefit in a number of ways. Drivers will experience increased handling performance on the street. Polyurethane bushings will endure wear and tear that rubber is incapable of withstanding. Installing new urethane bushings will tighten up a BMW that has been pounded loose in the bush.

Bushings should be one of the first thing to consider when modifying the suspension of a vehicle, particularly for go-fast applications. After the addition of performance polyurethane bushings, you're better able to judge what your next modification for that particular vehicle should be.

Polyurethane, when it is properly formulated, will increase the performance level of most suspensions. In a typical A-arm-type suspension, deflection of the rubber bushings during cornering, braking, and acceleration will allow the front end to temporarily go out of alignment. As the rubber bushings wear, they begin to compact and distort, introducing play into the suspension components. This play exaggerates a number of conditions, such as unresponsive steering, vehicle lean, wheel hop, and front-end misalignment. When you add oversized tires and increased suspension travel, it soon becomes apparent that a weakness exists in the chain. Anyone with an understanding of mechanics knows it's a rare machine that doesn't need all of the parts in its makeup to run at peak efficiency. This holds true for the chassis as well.

Polyurethane works by maintaining firm control over the suspension unit it adjoins. In many instances, the rubber-bushed suspension component will only begin its function once the rubber's displacement is halted by supporting metal. When rubber bushings are distorted and smashed, they allow contaminants to occupy the areas they used to. An example would be worn strut-rod bushings holding saltwater against the vehicle frame or worn tie-rod end dustboot covers that allow sand and other small particles to contaminate the lubricant. Contamination of this kind guarantees a speedy demise to any suspension component.

With the incredible popularity polyurethane is enjoying today in the automotive market, it's important to know what you're buying. Many people think that color is the only difference in polyurethane. However, nearly anyone can make a mold from an existing rubber bushing and "splash" out a polyurethane part. The art lies in formulating the mixture so that the part's durometer corresponds to its job: control-arm bushings should be firmer than bumpstops, for example. Polyurethane can be formulated for many different characteristics, such as abrasion, elasticity, elongation, and tear strength. It is combining the durometer with the proper physical properties that makes for superior polyurethane parts.