Maximum Motorsports IRS Subframe Bushings
Maximum Motorsports introduces a new product for IRS-equipped Mustangs: A Polyurethane IRS Subframe Bushing Kit. The polyurethane bushings in this kit are considerably less compliant than the stock rubber IRS subframe bushings. These stiffer bushings virtually eliminate displacement of the IRS subframe relative to the chassis. This reduces wheel hop during acceleration, braking and cornering. You'll feel a big improvement in your car's stability and predictability. Drivers have reported that the improvement is dramatic, similar to installing a Panhard Bar on a solid axle car. The polyurethane still provides very good noise isolation.
NOTE: It has been found that Ford had put the incorrect bolt in the front mounting holes for retaining the IRS subframe on some 2003 Cobras. The sleeve in the bushing and hole in the chassis are designed for a 14mm diameter bolt, however many cars had 12mm bolts installed incorrectly from the factory. If you have been noticing noise from the rear suspension, it may be caused by the subframe shifting due to insufficent retention with the smaller bolts. Verify the bolt size installed through the front IRS subframe mounts before ordering. If in doubt, or if you determine you need the larger bolts and corresponding nuts, the OEM replacements are available below. You will need two of each to do both sides.