Chrysler 45RFE 4th Clutch Bonded PistonTranstar now carries the 4th clutch bonded piston for Chrysler 45RFE transmissions, years 2005-up. In mid-stream 2005 several running changes were made to the 45RFE series transmission. The changes involve the 2nd/4th clutch housing and pistons. The previous pistons had removable seals, whereas the new design pistons are bonded rubber. The 4th clutch piston, D72961A, will not retrofit back due to the seal cut of the early piston/housing. Therefore, the 4th clutch piston and housing must be used as a set, 1st or 2nd design.