Richmond LS201028 POSI LIMITED-SLIP DIFFERENTIAL – GM 10 BOLT 8.5 inch – 28 SPL. This product data sheet is originally written in English. POWERTRAX – GRIP LS POSI LIMITED-SLIP DIFFERENTIAL – The POWERTRAX Grip LS is the latest design in traction adding differential technology. It combines the smooth operation of a limited-slip differential, with the strength of a fully machined case. Using carbon-fiber and steel friction plate technology, the POWERTRAX Grip LS delivers streetable and consistant traction. You asked for it and we made it, an all-new complete case, s-spring preloaded limited-slip differential. The POWERTRAX Grip LS comes fully assembled. Because there are friction plates on machined internal gears, it is fully rebuildable. This is as close as it gets to a traditional and trusted muscle car or truck style limited-slip. GM 10 BOLT 8.5 inch – 28 SPLINE. Richmond LS201028 POSI LIMITED-SLIP DIFFERENTIAL – GM 10 BOLT 8.5 inch – 28 SPL POWERTRAX – GRIP LS POSI LIMITED-SLIP DIFFERENTIAL – The POWERTRAX Grip LS is the latest design in traction adding differential technology. GM 10 BOLT 8.