66RFE Input Drum, new and ready to install. Fits the 66RFE. Ships fast from the USA.
If you are rebuilding the input clutch on a 45RFE or 68RFE and the underdrive piston came out hard, torn or scorched, this kit replaces the two pieces that apply that clutch. The listing title says input drum, but the part is the underdrive bonded molded piston together with its piston retainer, sold as a set (part numbers 72964 and 72984). Both go inside the one input drum these transmissions use. It is a small-ticket fix that matters to the Ram 2500 or 3500 Cummins owner and to the Jeep and Dodge 45RFE owner whose truck slips in the low gears or will not hold after a rebuild with the original pieces.
The input drum houses three clutches: underdrive, overdrive and reverse. The retainer forms the sealed chamber the underdrive piston works in, and the two fit together as a pair. When the transmission computer energizes the underdrive solenoid, oil enters behind the piston and clamps the underdrive pack. Chrysler's clutch application chart has that clutch on in every forward gear from First through Third on the five-speed RFE, and on the six-speed 68RFE the underdrive solenoid feeds it in First through Fourth, so this piston is working more of the time than any other in the unit. Because it is a bonded design, the seal is molded onto the piston, and the sealing surface on the retainer has to be clean and true for it to hold pressure.
Check the hot fluid level and pull codes first, then note which gears slip. Slip on the 3-4 or in the overdrive gears points to a different circuit, covered in our 68RFE 3-4 clutch failure guide. Low-gear slip with good overdrive gears, plus a failed air check of the underdrive circuit at the input drum, points here. Our 68RFE Ram 3500 shift problems guide covers the road test and scan data to collect before tearing in.
The listing names the 45RFE and 68RFE Dodge transmissions. The 545RFE and 65RFE use a similar input drum layout, but the listing does not name them, so match your parts. Lay your old piston and retainer next to the new ones and compare the outside diameter, seal profile and tab pattern before you assemble. If you would rather we check, send your year and VIN. You can find drums, frictions and seal kits for these units on the 68RFE parts page and the 45RFE parts page.
| Fits | 66RFE |
| Part type | Input Drum |
| Condition | New |
| Brand | OEM |
| Ships | From the USA |
| Warranty | 1-year |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
No. It is the underdrive bonded piston and the piston retainer it works in. Both install inside your existing input drum; the drum housing is sold separately.
The listing names the 45RFE and 68RFE only. These units share a similar input drum, but confirm by comparing your old piston and retainer to the new parts, or send us your year and VIN.
The piston seals against the retainer, and the two work as a pair. Installing a new bonded piston into a worn or scored retainer can leave the circuit leaking.
Drum sealing rings and O-rings, underdrive frictions and steels if they show heat, and a full gasket and seal kit for the rest of the unit.
ATF+4 only. Use it during assembly and for the refill, and set the level hot.
