P0740 on RAM: How to Diagnose & Fix
Torque Converter Clutch Circuit Malfunction
2 RAM models · 3 documented issues · 3 critical · $300-$8,000 repair
P0740 on RAM by model: symptoms, diagnosis and fix
The 2007-2018 RAM 3500 with the 68RFE 6-speed automatic transmission suffers from premature failure when towing heavy loads (over 10,000 lbs). The 68RFE is a derivative of the older 545RFE and was not adequately engineered for the torque output of the 6.7L Cummins. The overdrive clutch pack, solenoid pack, and torque converter are the primary failure points. Overheating during sustained towing destroys the clutch packs and warps the valve body. Many trucks experience complete transmission failure between 80,000-150,000 miles if used for regular towing. Rebuild cost: $3,000-5,000. Built/upgraded transmission: $5,000-8,000.
Common Symptoms
- Transmission slipping under heavy load
- Flare between 3rd and 4th gear
- No 3rd gear or no overdrive
- Transmission overheating warning while towing
- Harsh or delayed shifts
- Check engine light with transmission codes
- Complete loss of forward or reverse gears
How to Fix
For minor issues: Complete fluid and filter change with Mopar ATF+4 (68218057AA) and solenoid pack replacement ($400-800). For overheating prevention: Install an auxiliary transmission cooler and keep temps under 220F. For rebuilds: Use a reputable heavy-duty builder (SunCoast, Randys Worldwide, BD Diesel). A properly built 68RFE with billet shafts, upgraded clutch packs, and triple-disc torque converter ($5,000-8,000) will handle 800+ lb-ft of torque. For 2019+ trucks, the Aisin AS69RC replaced the 68RFE.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Geno's Garage QSK2004 68RFE service kit
Verify transmission, pan and required fluid quantity.
- Genuine Mopar ATF+4 68218058AC
68RFE only; verify transmission and service versus overhaul fill quantity.
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Sources for this issue (3)
The RAM 3500 equipped with the Aisin AS69RC 6-speed automatic transmission experiences torque converter shudder, overheating when towing, delayed shifts, and premature wear. The torque converter lockup clutch develops a shudder at light throttle and highway speeds. When towing heavy loads (10,000+ lbs), the transmission temperature can spike rapidly, triggering limp mode. TSB 21-013-19 addresses torque converter shudder with updated fluid and converter. The AS69RC uses a specific Aisin fluid (Mopar 68218058AA) and using incorrect ATF+4 causes accelerated wear. Converter replacement runs $2,000-3,500.
Common Symptoms
- Shudder or vibration at highway speed (40-60 mph)
- Transmission overheating when towing
- Delayed or harsh shifts
- Transmission temperature warning light
- Limp mode activation while towing
- Slipping sensation during light acceleration
- Torque converter lock/unlock cycling
How to Fix
For shudder: First try a complete fluid change with Mopar Aisin-specific ATF (68218058AA) - NOT standard ATF+4. If shudder persists, torque converter replacement is needed ($2,000-3,500). Check TSB 21-013-19 for updated converter part number. For overheating: Install an auxiliary transmission cooler ($200-400, B&M or Derale) and reduce towing speed. Ensure the external transmission filter (if equipped) is clean. Some 2013-2018 trucks qualify for extended warranty coverage on the Aisin transmission.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Genuine Mopar ASRC transmission fluid 05189966AF
AS69RC/AS68RC/AS66RC applications specifying 05189966AF or supersession; verify transmission and package quantity.
- Genuine Mopar 68224232AA AS69RC transmission filter
2013-2018 Ram 3500 high-output 6.7L Cummins with AS69RC as listed; not Ram 2500 and not approved here for 2019-2025. Fitment/availability: In stock at review
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Sources for this issue (4)
The 68RFE 6-speed automatic behind the Cummins is prone to torque converter shudder and lockup failure. The factory converter's clutch material and heat control are marginal for the Cummins' torque, so the torque converter clutch (TCC) chatters, slips, or refuses to hold lockup, felt as a low-speed vibration like driving over rumble strips. The TCC regulator valve wears its bore in the valve body, making apply pressure erratic. The resulting heat contaminates the fluid and cascades into planetary and clutch-pack damage. Heat is the number-one killer, especially when towing; fluid temps regularly over 200°F accelerate failure.
Common Symptoms
- Shudder/vibration around 40-55 mph (converter lockup)
- Slipping or flaring on lockup
- High transmission temperatures when towing
- Harsh or delayed shifts
- Burnt-smelling ATF+4 fluid
- Check engine light with TCC codes
How to Fix
Replace the torque converter with a stronger billet/multi-disc unit (e.g., Sun Coast, BD Diesel, or Suncoast triple-disc) rather than another stock converter. Rebuild or upgrade the valve body / TCC regulator valve (Sonnax) to restore correct apply pressure. Add an auxiliary transmission cooler and use the correct ATF+4 fluid, and consider a deep pan and improved fluid capacity for towing. Address early to avoid a full transmission rebuild.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- BD Diesel 1070220X ProForce enhanced-stall 68RFE torque converter
Restrict approval to manufacturer-cataloged 2007.5-2018 Ram 2500/3500 6.7L with 68RFE; verify early-2011 six- versus eight-bolt configuration and core terms. Do not extrapolate seller claims through 2024 without PI-curve/year confirmation.
- Genuine Mopar 68218058AC ATF+4 fluid
ATF+4/MS-9602 applications only; confirm container size, exact service quantity and current service information.
As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.
Sources for this issue (3)
P0740 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0740 mean on a RAM?
P0740 stands for "Torque Converter Clutch Circuit Malfunction." This code indicates a malfunction in the torque converter clutch (TCC) circuit of an automatic transmission. The torque converter clutch mechanically locks the engine to the transmission at cruising speed to improve fuel economy and reduce slippage, and it is engaged by a solenoid controlled by the transmission computer. The code sets when the computer detects an electrical problem with the clutch circuit or sees that the clutch is not engaging or holding as expected. Common signs include slipping, shuddering, poor fuel economy, or stalling when coming to a stop. On RAM it is documented across 2 models: 3500, 2500.
What are the most common causes of P0740?
The most common causes of P0740 are: Faulty torque converter clutch (TCC) solenoid, Low or contaminated transmission fluid, Wiring or connector fault in the TCC circuit, Worn or failing torque converter, Valve body wear or sticking valves, Internal transmission electrical short, Faulty transmission control module. The specific cause varies by vehicle.
How much does it cost to fix P0740 on a RAM?
Published repair estimates on RAM range from $300 to $8,000 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for P0740 on a different make?
View P0740 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.