Your 1979-98 Mustang was built using rubber bushings in the control arms. Urethane control arm bushings deflect less for better handling and straight-line traction. Complete sets include bushings for upper and lower arms unless otherwise noted. Original bushing shells must be re-used unless otherwise noted.
The suspension bushings included with this part can only be lubricated with PTFE grease, also referred to as "Marine Grease". PTFE grease is a very sticky, opaque grease that is water proof and will not degrade the bushing material. If lubed properly at installation, these bushings will not need to be lubricated again. Use of any other grease on these bushings will cause the bushing to fail and any bushing warranty to be voided.
Lifted or lowered suspensions, increases in horsepower, plus-size wheels and tires can subject traditional rubber suspension bushings to forces beyond their limits. Control arms, strut arms, leaf springs, body mounts, motor mounts, transmission mounts, sway bars and shocks all control movement and maintain alignment but the rubber bushings they use are designed for more "middle of the road" use. Rubber also deteriorates over time, further reducing control. This contributes to premature component failure, a "spongy" ride and less than ideal performance handling. Urethane bushings can correct these conditions, and improve drivability in your Mustang or Ford Lightning.