It's common for the factory shifter seat to wear, crumble and disintegrate over time. This often results in a sloppy or loose transmission shifter. The factory seat is soft so it can be squeezed into position. We took a different approach, and machined groves into the sides of our heavy duty seats. Instead of squeezing the seat into place, the groves on each side allow ours to rotate into position. This allows us to make our seat from stronger, longer lasting hardened urethane. Our new heavy duty seats will far out last the stock units and will reduce shifter slop. Please state year and model when ordering. Two different sizes, one sizes fits W56A and W56-B models, the other fits all other 4WD applications as well as all Toyota Celicas and Supras.