This is taken froma link in the Technical Database, Can anyone else support this?
Dispelling other myths:
Why isn't Polyurethane a good bushing material?
* "...virtually no deflection..." (cut and pasted from their web page). As mentioned above, the engineers that design these cars employ rubber bushings because deflection is required in most locations.
* "But I lubed them well, or I used Polygraphite® bushings": You are asking the poly material to act like metal bushings, and it can't. Lubing will temporarily reduce the squeaking and stiction. The graphite-impregnated versions are just 'pre-lubed', and once the graphite has worked its way out, the bushings will squeak and require regular lubing like the others. Lubing does nothing for the binding problem.
* "They get quieter over time": Poly will cold-flow, meaning it will deform under pressure and not return to normal, as it lacks the elasticity of the rubber bushings. Over time, they will loosen and then rattle. Check out the shape of your swaybar's poly end-link bushings after only a few months. This cold-flow issue can also lead to alignment problems on the front control arms, as the bushings deform.
* "But everyone sells them". Well, yes, and the manufacturers of Slick 50 and the makers of 'ultra/super white' bulbs could line up a long list of satisfied customers, but what would that mean?
* "Testimonials are everywhere!" but they don't convey the facts. Don't' believe everything you read in a glossy brochure or web page. Ever watch those late night infomercials? Like those other automotive miracles, wouldn't the large manufacturers pick up on this stuff if it really lived up to all it's claims?
* "But lots of other people use them!" As mentioned above, trailing arm suspension requires deflection in order to work, and when poly bushings are used, the required deflection is still there -- in the bending of the arms, mounting points, and flex of the rear tires. This is why these bushings appear to work fine for street applications.
Why isn't Polyurethane a good bushing material?
* "...virtually no deflection..." (cut and pasted from their web page). As mentioned above, the engineers that design these cars employ rubber bushings because deflection is required in most locations.
* "But I lubed them well, or I used Polygraphite® bushings": You are asking the poly material to act like metal bushings, and it can't. Lubing will temporarily reduce the squeaking and stiction. The graphite-impregnated versions are just 'pre-lubed', and once the graphite has worked its way out, the bushings will squeak and require regular lubing like the others. Lubing does nothing for the binding problem.
* "They get quieter over time": Poly will cold-flow, meaning it will deform under pressure and not return to normal, as it lacks the elasticity of the rubber bushings. Over time, they will loosen and then rattle. Check out the shape of your swaybar's poly end-link bushings after only a few months. This cold-flow issue can also lead to alignment problems on the front control arms, as the bushings deform.
* "But everyone sells them". Well, yes, and the manufacturers of Slick 50 and the makers of 'ultra/super white' bulbs could line up a long list of satisfied customers, but what would that mean?
* "Testimonials are everywhere!" but they don't convey the facts. Don't' believe everything you read in a glossy brochure or web page. Ever watch those late night infomercials? Like those other automotive miracles, wouldn't the large manufacturers pick up on this stuff if it really lived up to all it's claims?
* "But lots of other people use them!" As mentioned above, trailing arm suspension requires deflection in order to work, and when poly bushings are used, the required deflection is still there -- in the bending of the arms, mounting points, and flex of the rear tires. This is why these bushings appear to work fine for street applications.
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