Complete set of molded rubber-bonded clutch pistons for the Dodge Ram 66RFE and 68RFE: underdrive, low/reverse, 2nd, and 2-4, replaced on any overhaul.
This is the full set of bonded clutch apply pistons for the Chrysler/Dodge 66RFE and 68RFE automatics behind the 6.7L Cummins and 5.7L Hemi trucks, 2007 and up (Ram 2500 and 3500). A bonded piston has the seal molded directly onto the aluminum body instead of a separate lip seal, so the whole piece is replaced as a unit when you rebuild the transmission.
The kit covers the pistons the unit actually uses: the underdrive clutch piston, the low/reverse clutch piston, the 2nd clutch piston, and the 2-4 clutch piston. The rubber on the original pistons hardens and cracks with heat and miles, which bleeds apply pressure and shows up as a soft or slipping shift and rising line pressure. Fresh bonded pistons restore a clean, firm clutch apply.
Install these during a full teardown while the clutch packs are out, along with your frictions, steels, and a new gasket and seal set. Manufacturer part number K13900B-99, machined aluminum bodies. Ships from the USA, handling in 1-2 business days.
| Fitment | Dodge Ram 2500/3500 66RFE and 68RFE, 2007-up |
| Pistons included | Underdrive, Low/Reverse, 2nd, and 2-4 clutch pistons |
| Kit | Complete 5-piece bonded piston set |
| Seal style | Molded rubber bonded to body (no separate lip seals) |
| Body | Machined aluminum |
| Mfr part number | K13900B-99 |
