68RFE Planetary 2007-2018

This is a used original-equipment planetary gear set for the 68RFE, pulled from a 2008 Ram with the 6.7L Cummins and listed for 2007-2018 trucks. It is for the owner or shop whose Ram 2500 or 3500 has a whine that rises with road speed, has lost a gear, or came apart with chewed pinions and bearing pieces in the pan. Because it is a used factory part, the unit pictured is the unit you receive, and you are buying genuine factory gears rather than a reproduction set.

What the planetary does in a 68RFE

The RFE family uses three planetary gearsets where most four-speeds use two, and the clutches decide which member of each set is driven and which is held. Every ratio comes from those combinations. In the 68RFE they work out to 3.23 first, 1.83 second, 1.41 third, 1.00 fourth, 0.81 fifth, 0.62 sixth and 4.44 reverse. Fourth is a straight-through 1:1, so the gearset turns as a locked unit. Each other gear loads the pinions, needle bearings and thrust surfaces. Chrysler beefed up the internals over the 45RFE and 545RFE to take diesel torque. Even so, a heavy trailer, hot fluid and a lot of miles in fifth and sixth wear the pinion bearings and thrust faces first.

Symptoms of a worn planetary

• A whine or howl that follows road speed rather than engine rpm, often loudest in one gear
• One gear missing or slipping while the others still work, with gear ratio codes in the P0731-P0736 range
• Bright steel or bearing needles on the pan magnet, beyond normal clutch dust
• Excess end play or a clunk when the load changes
• Reverse or first that goes away entirely after a pinion failure

How to confirm before you buy

Note which gear the noise or slip is in and whether it follows road speed. A noise that changes with engine speed in park usually points to the pump or converter instead. Pull the pan and sort the debris: friction fines come from clutches, while steel flakes and needles mean hard parts. Our 68RFE Ram 3500 common problems guide covers how a cooked unit fails, and the pump failure guide helps rule out a pump noise before you tear the gearset down. Check speed sensor data too; the speed sensor guide explains how a bad sensor can fake a ratio code.

Fitment

This set came out of a 2008 Ram and is listed for 2007-2018 68RFE transmissions in Ram 2500, 3500 and heavy-duty Cummins trucks. The 2019-and-later 68RFE had a number of internal updates and is not included here. Compare the pinion count, splines and carrier against your old set before installing, and send us your year and VIN if you are unsure. As a used part, it should be inspected on the bench like any core you would put back in. Check the pinions for pitting, the carriers for cracks and the bushings for wear. The full range of parts is on our 68RFE collection page.

Install notes

• Measure pinion end play on each carrier and spin every pinion by hand; any roughness or catch means a bearing problem.
• Replace the thrust bearings, thrust washers and bushings during the job. The 68RFE master rebuild kit covers the frictions, seals and gaskets, and the Mopar overhaul kit is a soft-parts alternative.
• Set overall end play with the selective thrust washers. A 2025 Ram service bulletin on cracked rear selective thrust washers in some 2024 trucks shows how much these small parts matter.
• Flush or replace the cooler, because metal from a gear failure hides in the lines.
• Fill with ATF+4 only, check the level hot, and run the TCM quick learn before towing.

Is this a new or used planetary set?

Used original equipment, removed from a 2008 Ram with the 6.7L Cummins. The unit in the photos is the one that ships.

Will it fit my 2019 or newer Ram 2500?

It is listed for 2007-2018 trucks only. The 2019-up 68RFE had internal changes, so send us your VIN before ordering for a later truck.

How do I know my noise is the planetary and not the pump?

A planetary noise follows road speed and is often worse in one gear. A pump or converter noise is present in park and changes with engine rpm.

What should I replace along with it?

The thrust bearings, thrust washers and bushings, plus any clutches that were damaged by debris. Flush the cooler so metal from the old set does not return.

What fluid does the 68RFE take?

ATF+4 only. Set the level with the fluid hot, then run a quick learn with a scan tool.

• 68RFE Ram 3500 Cummins Common Problems and Fixes
• 68RFE Pump Failure: Symptoms, Diagnosis, and Replacement
• 68RFE Input and Output Speed Sensor Symptoms, Testing and the P0716 Trap
• 48RE vs 68RFE: Differences, Interchange, and Which Is Stronger