Billet accumulator pistons, PTFE seals and a thicker steel accumulator plate that fix scuffed bores and plate flex in 68RFE valve bodies.
If your Ram's 1-2 or 2-3 shift has gone soft and flared, or the truck bangs into gear one day and slips the next, the accumulator stack in the valve body is a likely suspect. This kit rebuilds that stack in the RFE family valve body: five billet aluminum accumulator pistons, ten solid PTFE guide seals, five scarf-cut PTFE seals, a reinforced steel accumulator plate with shim, and six screws with washers. It is built for the 68RFE behind the 6.7L Cummins in Ram 2500 and 3500 trucks, and it also fits the 45RFE, 545RFE, 65RFE and 66RFE from 1999 on.
Each accumulator is a spring-loaded piston teed into a clutch apply circuit. When a solenoid opens a circuit, part of that oil has to stroke the piston against its spring before full pressure reaches the clutch, which softens the apply and gives the shift a controlled ramp instead of a hammer blow. In the RFE design there is no oil pressure on the back side of the piston, only the springs, so seal drag and piston friction change the shift feel directly. Sonnax points out that the factory piston is guided at only one end. Side load can push the primary seal down into its deep groove until bare piston rubs the aluminum bore, and once the bore is scuffed, apply oil leaks past every shift.
The factory cover plate holding the stack is a second weak point. It flexes as the pistons hit it, the screws lose their grip, and they can back out or break. A loose plate lets the pistons cock in their bores and speeds up the wear.
Rule out the cheap items first. Check the fluid level hot, scan for codes, and look at the solenoid pack and its connector, because a sticking solenoid can mimic an accumulator leak. Our 68RFE valve body testing guide walks through the order of checks, and the Ram 3500 shift problem guide sorts shift complaints by cause. If the valve body is already on the bench, look straight at the accumulator bores. A bright polished band or a step you can feel with a fingernail, or a piston with scuff marks along one side, tells you the factory stack is done.
The kit is listed for the 45RFE, 545RFE, 65RFE, 66RFE and 68RFE automatics, 1999 and newer, which share the accumulator layout. In practice that covers the 68RFE in 2007-up Ram 2500, 3500 and cab-chassis trucks with the 6.7L Cummins, plus the gas RFE units in Ram 1500, Dakota, Durango and Jeep applications. The rest of the internals are not shared across the family, so confirm which unit you have from the transmission tag, or send us your year and VIN before ordering. You can browse other parts for your unit on the 68RFE parts page.
If the valve body is out because of shift complaints, this is the right time to fit a new 68RFE solenoid kit or a 68RFE shift kit, so you only pull the valve body once.
| Fits | |
| Pistons | |
| Seals | |
| Plate | |
| Hardware | |
| Manufacturer part number |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
Yes. The kit is listed for the 68RFE from 2007 on, along with the 45RFE, 545RFE, 65RFE and 66RFE, which share the accumulator bores and plate layout. Check the tag on the transmission or send us your VIN if you are unsure which RFE unit you have.
Yes. The kit replaces the pistons, seals, cover plate and hardware. Your original springs go back in, so keep each one in the bore it came out of when you take the stack apart.
Usually, if the wear is light. The new pistons have guide seals at both ends and the primary seal sits lower, on bore surface the factory seal never touched. Deep gouges or cracks mean the valve body should be replaced.
ATF+4. Fill it, run the truck until the fluid is at least 160 degrees F, then set the level on the dipstick. A low or overfilled RFE can shift badly and hide whether the repair worked.
Running the quick learn with a capable scan tool after valve body work is good practice. The TCM adapts clutch apply timing, and the new pistons change how quickly each circuit fills, so expect shifts to settle over the first drive cycles.
