68RFE Problems: Causes, Fixes & Repair Costs

Sun West Transmissions — Glendale, AZ. Free estimates, honest diagnosis and a 3-year / 40,000-mile warranty on qualifying rebuilds and replacements.

The Transmission Behind the Cummins

The 68RFE is a six-speed automatic used behind the Cummins diesel in Ram 2500 and 3500 pickups and cab-chassis trucks starting in the late 2000s. It is related to the 45RFE and 545RFE family but built for diesel torque and heavy towing. Many West Valley owners use these trucks to pull fifth-wheels, horse trailers and equipment, often in serious heat. That combination is where most 68RFE problems start.

Common 68RFE Problems

Limp Mode

Limp mode is one of the most common 68RFE complaints. When the transmission control module detects a problem, it locks the transmission in a fixed gear, typically second or third, to protect it. Causes range from a failing solenoid pack or pressure sensor to low line pressure from internal wear. Codes such as line pressure or gear ratio faults usually accompany it. Read what is limp mode and our page on code P0868.

Torque Converter Failure and Shudder

The converter in a diesel truck sees enormous torque. Converter clutch wear leads to shudder at cruise, slipping on grades and debris in the fluid. Severe converter failures can contaminate the entire transmission and cooler. Many owners choose a heavy-duty converter during repair, especially with added power.

Clutch Pack Wear and Slipping

Heavy towing and high fluid temperatures wear clutch packs. Slipping in certain gears, flare between shifts and delayed engagement are common on high-mileage or hard-working units. Certain clutch packs in the RFE family are known to wear first under heavy load.

Solenoid Pack and Pressure Sensor

The 68RFE uses an externally mounted solenoid and pressure switch assembly. Electrical faults, connector corrosion or internal solenoid failure can cause harsh shifts, erratic operation and limp mode. Because it is accessible, this can sometimes be repaired without removing the transmission.

Overheating

Towing in Phoenix summers pushes fluid temperatures up fast. A restricted cooler, failing cooler bypass or thermostat, or simply exceeding the trailer rating can overheat the fluid. Overheated fluid breaks down and shortens the life of every component. See why transmissions overheat.

Speed Sensor Problems

Input and output speed sensor failures can cause erratic shifting and limp mode, often with matching codes. These are relatively simple to test.

What You Can Safely Check

Check the fluid level with the engine running and fluid at operating temperature using the correct procedure for your model year. Look for leaks at the cooler lines and pan. Note whether limp mode happens only when hot or while towing. If the truck goes into limp mode, pull over safely, turn the engine off for a few minutes and restart; if it returns to normal, drive gently and get it checked soon. Do not continue towing a heavy load in limp mode.

How Sun West Diagnoses the 68RFE

We road test, loaded when appropriate, while monitoring line pressure, commanded and actual gear, converter slip and fluid temperature. We scan for codes and check the solenoid pack and pressure sensor circuits. Fluid and pan inspection shows whether there is clutch or converter debris. A clear diagnosis tells us whether an external repair will solve it or whether the transmission needs to come out. See our diesel transmission repair page.

Repair Options

• Electrical repair of sensors, connectors and the solenoid pack.
• Cooling improvements, including an auxiliary cooling system for trucks that tow.
• Heavy-duty torque converter replacement.
• Valve body repair for pressure and shift-control problems.
• Rebuild with upgrades for clutch wear and internal damage. See our 68RFE transmission page and transmission upgrades.

What It Costs

Cost depends on the truck, the failure, the converter choice and any upgrades for towing or added power. Call (623) 473-9800 for a free quote, and see our Ram transmission prices page for how pricing works. Qualifying rebuilds and replacements include our 3-year / 40,000-mile warranty with no deductible on covered repairs, and financing is available.

When to Stop Driving

Stop towing if the truck slips, overheats, or goes into limp mode under load. If the transmission slips severely or will not move, stop driving. Continuing can destroy the converter and spread debris that makes the repair much larger.

68RFE Problems: FAQ

Why does my 68RFE go into limp mode only when towing?

Heat and load expose weak pressure, worn clutches or a marginal solenoid pack. The computer sees slip or low pressure and protects the transmission.

Do I need a stronger transmission if my Cummins is tuned?

Added power puts more load on the clutches and converter. A rebuild with upgraded parts is usually recommended.

Do you work on Ram 3500 cab-chassis trucks?

Yes. See our Ram 3500 and Ram 2500 pages.