68RFE Pump Failure: Symptoms, Causes and Rebuild vs Replace

68RFE Pump Failure: Symptoms, Causes and Rebuild vs Replace

68RFE Pump Failure: Symptoms, Causes and Rebuild vs Replace

The front pump is the heart of the 68RFE. Every clutch pack, the torque converter and the lube circuit run on the oil it moves, so when the pump wears, everything downstream suffers. Behind the 6.7L Cummins in Ram 2500 and 3500 trucks, the 68RFE pump sees heat, high line pressure and converter loads that wear it out faster than a light-duty unit. This guide covers how the 68RFE pump is built, what a failing one looks like, what actually kills it, and when the pump can be rebuilt instead of replaced - based on published guidance from Sonnax, Transmission Digest and Green Handle Media.

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68RFE Sonnax Heavy Duty Outer Pump Gear Set 72530B-04K
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How the 68RFE Pump Is Built

The 68RFE uses a gear-type pump with three gears: a center gear plus two outer gears. Sonnax describes the center gear as having a drive flange that passes through the pump body and rides on a bearing surface in the pump bore, and it ties center gear wear to play and noise at the turbine hub engagement. The pump body is made in two halves with a pump plate and gasket between them - TransTec notes that RFE pump plate gaskets "help prevent cross leaks between the two halves of the pump body."

Know which pump you have before buying parts. Sonnax reports that in 2019 the 68RFE behind the 6.7L diesel received hydraulic control changes: the pump plate was changed, the pump cover changed dimensionally for the revised TCC regulator lineup, and the TCC accumulator retainer, spring and piston were eliminated - an easy visual ID on the pump.

Symptoms of a Failing 68RFE Pump

  • Pump noise - Sonnax lists noise concerns as a symptom of center gear wear, and notes its redesigned center gear drive flange reduces turbine hub engagement play and noise.
  • Scoring where the center gear passes through the pump body - Sonnax lists this as a symptom found on 68RFE pumps.
  • Scored or fractured pump gears found at teardown - Sonnax lists "pump gear wear or fracture" as a core 68RFE pump symptom.

If the truck went no-drive right after a fluid and filter service with a P0944 code, start with our 68RFE P0944 loss of pump prime guide - that is usually a filter sealing problem, not a worn pump.

Diagnosis: Prove It Is the Pump

  1. Read actual vs desired line pressure on a scan tool. RFE units report line pressure and line pressure duty cycle, so you can compare what the TCM is commanding to what the pump is delivering.
  2. Confirm with a mechanical gauge. Sonnax gives normal OE pressure for these units as 60 psi minimum and 150-160 psi maximum at stall (unit dependent). A reading well below that minimum, with the pressure control circuit working, means the pump is not delivering and the unit needs to come apart.
  3. Rule out the opposite fault. Sonnax documents that 150-160 psi at idle in Park, Neutral and Drive and 250 psi in Reverse can indicate an open circuit on the line pressure control solenoid - common on 2013-era 6.7L Rams. That is an electrical problem, not a pump problem. Our 68RFE max line pressure guide covers it.
  4. Inspect at teardown. Sonnax says to inspect the pump bore and the pump pocket face below the center gear. Those two surfaces decide whether the pump is rebuildable.

What Causes 68RFE Pump Failure

1. Normal gear wear from mileage and pressure

Sonnax states plainly that time, mileage and high pressure contribute to wear of the OE pump gears in the 68RFE - and that replacement gears are not available from Chrysler to rebuild a worn pump.

2. Center gear bore scoring

Sonnax reports that 68RFE pump bodies are frequently found with a scored bearing surface, or wear and fractures, where the center gear drive flange passes through the pump. Sonnax attributes the cause to excess pump body wear.

3. Converter overheating and ballooning

Green Handle Media reports that 68RFE pump damage usually follows a converter failure: an overheated converter expands, removes the clearance at the pump and effectively pushes the pump gears into the housing, leaving scored gears. Sonnax adds that on RFE units, full TCC apply pressure equals line pressure - roughly 160 psi stock - and performance setups running over 220 psi can balloon the converter and eventually damage the pump assembly and bellhousing adapter.

4. Flexplate failure

Green Handle Media also notes that a failed factory flexplate can create excessive thrust that damages the pump, which is why rebuilders it cites recommend an upgraded flexplate in any 68RFE rebuild. See our 68RFE flexplate guide.

The Fix: Rebuild vs Replace the Pump

The deciding factor is the pump pocket face. Here is how Sonnax frames it:

  • Worn gears, good bore and pocket - rebuild. Replace all three gears: the Sonnax heavy duty outer pump gear set 72530B-04K (two high-pressure gears with an anti-wear coating) used together with the Sonnax center pump gear 72530B-02. Sonnax notes the stepped side of the outer gears faces up toward the plate.
  • Scored center gear bore, good pocket - rebuild with a bushing. The bore is machined oversize to remove the score damage, then a precision steel-backed aluminum Sonnax center pump gear bushing 72530B-03 is installed. Sonnax specifies the bore must be machined to 2.172" +/- .0005" before the bushing goes in.
  • Damaged pocket face - replace the pump. Sonnax is explicit that damaged pockets cannot be repaired with these parts.
Sonnax 72530B-04K heavy duty outer pump gear set for the 68RFE transmission
Sonnax 72530B-04K heavy duty outer pump gear set for the 68RFE

Because Chrysler does not supply the gears separately, a rebuild with aftermarket gears is often the only way to save a worn pump body. If the pump plate is damaged or you are rebuilding the full assembly, a 68RFE coated pump plate is also available - match it to the pre-2019 or 2019-up pump. Browse all transmission pumps or the full 68RFE parts collection.

Replace While You Are In There

  • Pump plate gasket - the gasket that separates the two pump body halves and prevents cross leaks, per TransTec. TransTec's revised gasket fits 2019-and-later 68RFE pumps and is backward compatible with other RFE models.
  • Torque converter - if the pump gears are scored, Green Handle Media ties that to converter heat and expansion. Reinstalling the same converter risks repeating the failure.
  • Flexplate - an upgraded unit such as a 68RFE billet flexplate addresses the thrust failure Green Handle Media describes.
  • TCC apply pressure control - on tuned or boosted trucks, Sonnax recommends limiting TCC apply pressure to protect the converter and, in turn, the pump.

Cost and Effort

The pump parts themselves are a small share of the job. The labor is in pulling the transmission to get the pump out. Rebuilding the pump also requires careful inspection, and bushing a scored bore requires machine work to a tight tolerance - a job for a shop with the right equipment. A pocket-damaged pump is a replace-only situation, so confirm the pocket condition before ordering parts. Addressing the converter, flexplate and pressure causes at the same time is what keeps you from pulling the transmission twice.

Frequently Asked Questions

Can a worn 68RFE pump be rebuilt?

Usually, yes, if the pocket face under the center gear is undamaged. Sonnax offers replacement center and outer gears plus a center gear bore bushing. If the pocket is damaged, Sonnax says to replace the pump.

Can I buy 68RFE pump gears from Chrysler?

According to Sonnax, replacement pump gears are not available from Chrysler to rebuild a worn pump, which is why aftermarket gear sets exist.

Why do 68RFE pump gears get scored?

Green Handle Media links scored pump gears to converter overheating and expansion, and to thrust from a failed flexplate. Sonnax also points to excessive TCC apply pressure on high line pressure builds.

Sources