Whether to Use Urethane Bushings or Solid

   Rubber suspension bushings are great for noise insulation, but with time they will deteriorate and become too flexible. Most stock vehicles use rubber  suspension bushings everywhere, control arms, steering rack, swaybar, endlinks. And just after a few years the suspension bushings will start to deteriorate.   

   At the steering rack for example, the suspension bushings  will let the rack move up & down and side to side with every bump in the road, this is not what  you want to happen, it will get worse if you vehicle is lowered. The lower arm suspension bushings  will also move, dynamically changing the front wheel  alignment making it very unpredictable in road racing applications, One way to improve the front suspension is to use solid or urethane suspension bushings.

   Solid suspension bushings are the best if your car is a road racer, but on the street they are very noisy, urethane allows some noise insulation but being  harder than rubber they will also get rid of that mushy front suspension response.

  Installing stiffer lower arm suspension bushings will keep your alignment in range on those tight turns and will improve steering response. The same  guidelines apply with the steering suspension bushings, solid ones for Road Race only and urethane for street.

   In lowered vehicles the front end geometry suffers when the relationship between the lower arms and steering rack changes. This increases  bump steer or the tendency of the front to turn when you hit a bump. In order to reduce bumpsteer, some people recommend offset steering rack suspension bushings.

   This is not a good idea, in these suspension bushings  the center hole is offset in order to compensate for the rack & arms relationship. They can rotate  changing the relationship of rack and arms more and increasing bumpsteer further. You will be better off getting a normal, non offset, set of urethane  suspension bushings.

  One thing to do to the new suspension bushings is to install a zerk grease fitting. Place the suspension bushings in their shells and drill a hole in  each, big enough to screw in a zerk grease fitting. Installation is easy but the whole process takes time as you have to remove most of the front suspension  components.

   With new urethane suspension bushings the improvement over stock is very noticeable, rubber suspension bushings will allow all the components to move making the suspension flex. New suspension bushings will eliminate bumpsteer and steering will be predictable and more responsive.