STI hardened rubber bushings, either sold as a kit or individually, to improve handling, traction, and steering response. Rubber hardness is increased noticeably over stock parts but is within the limits for Group N use. Manufactured with the same quality and on the same production line as the OEM bushings.
NOTE: Select your kit depending on the front control arms used. High caster front control rear bushings and both application front control arm front bushings are OEM parts.
Usually ships the next business day.
Did you change your bushing kits recently? We made some changes so that we could supply more complete bushing kits and avoid some confusion about product fitment that some customers were experiencing. We now include some OEM bushings where STI uprated hardened versions don't exist. We are also including the trailing link front bushings on certain applications where they don't technically meet the group N regulations because few customers actually need to concern themselves with meeting strict FIA regulations.
What are the differences between RSTBKN12 and RSTBK2 kits? The only difference that now exists has to do with the front control arm rear bushings. Most STI applications use an aluminum control arm that increases the caster angle above that used on other models. These "high caster" arms use a bushing that has a different taper angle where it fits over the shaft of the arm (transverse link shaft). There is no Group N hardened bushings to replace them because the factory OEM bushing is already at the maximum hardness allowable. Therefor RSTBKN12 contains OEM replacements for this bushing while RSTBK2 contains the STI Motorsport Group N hardened bushings for the "standard caster" aluminum or steel arms.
How can I determine if I need RST-4154 or RST-4154X for the RH side of the rear diff front crossmember? There is a production date of 01/2002 for the changeover. However, visually they can be identified by the height of the bushing. The earlier models use the same bushing for both sides. The later models will have a taller bushing on the RH side compared to the LH side and therefore will take RST_4154X for the RH side.
How do these bushings compare to urethane bushings? These are rubber bushings with a higher durometer than the factory ones. In terms of hardness they are comparable to most aftermarket urethane bushings. However, urethane and rubber bushings operate differently. Urethane bushings rotate in a sliding motion around the center sleeve and require lubrication. If the lubrication washes out or dries up the bushing may begin to make noise and can wear prematurely. A rubber bushing, on the other hand, has no sliding motion under normal conditions, but instead the material twists or distorts around the center sleeve to allow the suspension arm to articulate. A rubber bushing will not wear unless the material deteriorates. Exposure to heat, chemicals, ozone, UV light, etc. can break down the rubber.
How difficult are they to install? Installation requires the use of a hydraulic press. Some bushings use an outer metal sleeve that may need to be split in order to press the bushing out of its bore. Installing the new bushings without damaging them may require the fabrication of special tools. It is a job best left to a skilled professional.
