68RFE Transmission Problems: A Guide for Owners and Mechanics!

If you own a Dodge Ram truck with a 6.7L Cummins diesel engine, chances are you have a 68RFE transmission. 

This six-speed automatic transmission was designed to handle the high torque and power of the Cummins engine, but it also has some common problems that can affect its performance and reliability. 

In this article, we will explore some of the most frequent 68RFE transmission problems, such as slipping, hard shifting, low pressure, and torque converter failure. 

We will also explain the causes, symptoms, and solutions for these issues, and provide some tips on how to prevent them from happening in the first place. 

Whether you are an owner or a mechanic, this guide will help you understand the 68RFE transmission better and keep it running smoothly for a long time.

What does 68RFE mean?

The code “68RFE” stands for several key features of the automatic transmission it identifies:

• 6: This signifies it’s a 6-speed transmission.
• 8: This refers to the relative torque rating. In this case, 8 indicates it can handle a relatively high level of torque compared to other transmissions.
• R: This stands for Rear-wheel drive. This transmission is designed for vehicles with rear-wheel drivetrains.
• F: This signifies Fully Electronic control. The transmission operation is completely managed by an electronic control unit (ECU).
• E: This denotes the Electronic version of the transmission. There were some earlier, non-electronic versions of the RFE transmission with slightly different designations.

Also Read: A Guide To 2014 Ford Focus Transmission Replacement Cost!

What Are The 68RFE Transmission Problems?

The 68RFE transmission, while found in popular vehicles like Dodge Ram trucks with Cummins engines, has a reputation for being unreliable and prone to a variety of problems. Here are some of the most common issues:

1. Valve Body Cross Leakage

This is often considered the most common problem with the 68RFE. The valve body, which controls the flow of fluid throughout the transmission, can develop internal leaks, causing erratic shifting, slipping, and even complete transmission failure.

2. Burnt Overdrive Clutches

The overdrive clutches are responsible for engaging the highest gear, allowing for fuel-efficient cruising. They are a weak point in the 68RFE’s design and can easily burn out, especially under heavy loads or aggressive driving. This can lead to a lack of overdrive functionality, limited gear selection, and slipping.

3. High-Pressure Oil Pump Issues

The unique three-gear design of the 68RFE’s pump can wear out prematurely, leading to a loss of line pressure. This low pressure directly affects the ability of the transmission to shift gears and engage clutches smoothly, resulting in slipping, harsh shifts, and even failure.

4. Runaway Torque Converter

This problem arises when the torque converter, responsible for transmitting engine power to the transmission, fails to disengage properly. This can lead to a lack of engine braking, overheating, and even damage to the transmission itself.

5. Broken Sprag Assembly

The sprag assembly is a one-way clutch that allows the engine to turn the transmission but not vice versa. It can break under heavy loads or due to wear and tear, causing a complete loss of drive and potentially damaging other transmission components.

6. Other potential issues

Beyond the major points mentioned above, the 68RFE can also experience issues like worn solenoids, faulty sensors, and internal leaks in other areas.

What Are The Causes To These 68RFE Transmission Problems?

While specific cases might have unique contributing factors, here’s a breakdown of possible causes for the common 68RFE transmission problems:

1. Valve Body Cross Leakage

• Worn or damaged components: Over time, internal components in the valve body like valves, sleeves, and springs can wear or crack, leading to internal leaks.
• Contaminated transmission fluid: Dirty and old transmission fluid loses its lubricating properties, causing accelerated wear and tear on the valve body components.

2. Burnt Overdrive Clutches

• Towing heavy loads: The 68RFE is not designed for continuous heavy towing, which puts excessive strain on the overdrive clutches, causing them to overheat and burn.
• Aggressive driving: Frequent rapid acceleration and harsh gear changes increase the wear and tear on the clutches, leading to premature burn-out.
• Incorrect line pressure: Low line pressure can lead to clutch slippage, generating excessive heat and contributing to burning. (See causes for High-Pressure Oil Pump Issues below)

3. High-Pressure Oil Pump Issues

• Normal wear and tear: Like any mechanical component, the pump gears can wear down over time, reducing their efficiency and leading to decreased line pressure.
• Manufacturing defects: In some cases, faulty manufacturing processes could result in weaker pump gears, making them more susceptible to wear and tear.

4. Runaway Torque Converter

• Internal wear and tear: Similar to the oil pump, internal components of the torque converter can wear out, causing them to malfunction and fail to disengage properly.
• Contaminated transmission fluid: Dirty fluid can clog the converter’s passages, hindering its proper operation.
• Faulty torque converter solenoid: This electrical component controls the operation of the torque converter, and a malfunction can lead to issues like a runaway converter.

5. Broken Sprag Assembly

• Excessive towing or torque: Putting extreme stress on the transmission, especially through heavy towing or aggressive driving, can overwhelm the sprag and cause it to break.
• Manufacturing defects: Similar to the oil pump, faulty materials or imperfections during manufacturing can create weaker sprags, making them more prone to failure under stress.

6. Other potential issues

• Solenoid wear: Just like the torque converter solenoid, other solenoids can wear out and cause shifting inconsistencies.
• Sensor failure: Faulty sensors can send inaccurate information to the Transmission Control Module (TCM), leading to incorrect shifting and other problems.
• Internal leaks in other areas: Leaks in other transmission components can starve them of necessary fluid pressure and cause various malfunctions.

What Are the Symptoms Of 68RFE Transmission Problems?

The 68RFE transmission can exhibit a variety of symptoms when experiencing problems. Here are some common ones to watch out for:

Shifting Issues

• Slipping: This is a feeling of the engine revving high without a corresponding increase in speed, often accompanied by a burning smell. This can occur in any gear but is frequent during acceleration or gear changes.
• Harsh Shifts: The transmission jolts noticeably when shifting gears, indicating a lack of smooth engagement between clutches.
• Delayed Engagement: There may be a noticeable delay between putting the vehicle in gear and it actually starting to move.
• Stuck in Gear: The transmission can get stuck in a single gear and refuse to shift, limiting vehicle operation significantly.
• Loss of Overdrive: Inability to engage the highest gear, resulting in decreased fuel efficiency and potentially higher engine RPM at cruising speeds.

Performance Issues

• Lack of Power: The vehicle may struggle to accelerate or maintain speed, even with moderate throttle input. This can be due to internal transmission issues preventing proper power transfer.
• Shuddering: A vibration or shaking sensation felt while driving, often indicating a problem with the torque converter or clutch packs.
• Grinding Noises: Unusual grinding noises coming from the transmission area can point towards internal wear and tear or component failure.

Other Warning Signs

• Check Engine Light: This light can illuminate due to various issues, but can also be triggered by transmission problems in some cases.
• Burning Smell: A burnt odor emanating from the transmission is a serious symptom, indicating overheating or clutch burn, and requires immediate attention.
• Transmission Fluid Leaks: Leaks from the transmission pan or elsewhere under the vehicle can be a sign of internal problems or worn seals.

Important: 2011 Chevy Cruze Transmission Issues: Get Answers and Solutions Here!

How To Fix 68RFE Transmission Problems?

Fixing 68RFE transmission problems can vary greatly depending on the specific issue at hand. While some issues might be addressed with minor repairs or adjustments, others may require a complete rebuild or even transmission replacement. Here’s a general overview of potential approaches, but remember, attempting repairs yourself is not recommended without proper knowledge and experience.

1. Seek Professional Help

It’s crucial to consult a qualified mechanic with experience in automatic transmissions, especially the 68RFE. They can diagnose the problem accurately using a combination of:

• Diagnostic tools: Scanners and computers can read fault codes stored by the Transmission Control Module (TCM) that can point toward the source of the issue.
• Visual inspection: Mechanics can visually assess the transmission for leaks, wear, and other potential problems.
• Test drives: Evaluating the vehicle’s performance and symptoms further aids in diagnosis.

2. Potential Solutions (By a qualified mechanic)

Once the problem is identified, the mechanic can recommend the appropriate solution. Here are some possibilities:

• Fluid change and filter replacement: This is often a starting point, as contaminated or burnt fluid can contribute to various issues. The mechanic will use the correct type and viscosity of fluid for your specific vehicle.
• Solenoid or sensor replacement: Faulty solenoids or sensors can be replaced individually.
• Valve body repair or rebuild: Depending on the severity of the damage, the valve body might require repair or a complete rebuild.
• Clutch pack replacement: Worn or burnt clutch packs might need replacement, which often involves removing and partially disassembling the transmission.
• Torque converter replacement: If the torque converter is malfunctioning, replacing it might be necessary.
• Complete rebuild or replacement: In severe cases of damage or wear, a complete rebuild or even replacement of the entire transmission might be recommended.

3. Important Considerations

• Cost: Repairs can range from a few hundred dollars for minor issues to several thousand dollars for major repairs or rebuilds. Replacement transmissions can be even costlier.
• Warranty: If your vehicle is under warranty, consult your dealership before proceeding with any repairs. Unauthorized modifications or repairs might void your warranty.
• Experience & Reputation: Choose a mechanic with a good reputation and experience working on your specific vehicle and transmission model.

Is the 68RFE a good transmission?

Whether the 68RFE is a good transmission depends on your specific needs and priorities:

Strengths

• Towing Capacity: The 68RFE boasts a relatively high torque capacity compared to other 6-speed automatic transmissions of its era. This makes it suitable for towing and hauling moderate loads, especially compared to smaller transmissions.
• Lower Cost: Compared to some competing transmissions like the Aisin found in some Ram trucks, the 68RFE can be less expensive to repair or rebuild.
• Availability: Being a common transmission in Dodge Ram trucks, parts and mechanics familiar with the 68RFE are generally more readily available.

Weaknesses

• Reliability Concerns: Unfortunately, the 68RFE is notorious for having reliability issues, especially when pushed beyond its limits. It has been plagued by problems like valve body leaks, burnt clutches, and failing torque converters.
• Not Suitable for Heavy Towing: While it can handle moderate loads, the 68RFE is not ideal for heavy-duty towing or frequent aggressive driving. Overloading or pushing the transmission too hard can exacerbate its known weaknesses and lead to costly repairs.
• Fuel Efficiency: Compared to newer and more advanced transmissions, the 68RFE is generally considered less fuel-efficient.

Therefore, the 68RFE could be considered a good option for:

• Casual drivers who don’t tow or haul heavy loads frequently and prioritize affordability.
• Drivers who use their truck for light towing are comfortable with the potential for increased maintenance costs compared to more robust transmissions.

How long does 68RFE last?

It’s impossible to give a precise lifespan for a 68RFE transmission as it heavily depends on several factors:

• Maintenance

Regular maintenance, including timely fluid changes and filter replacements, significantly impacts the lifespan of any transmission, including the 68RFE. Proper maintenance can extend its life considerably.

• Driving habits

Avoiding excessive towing, aggressive driving, and overloading the vehicle significantly increases the 68RFE’s lifespan. Aggressive driving habits and exceeding its towing capacity put significant strain on the transmission, leading to premature wear and tear.

• Previous repairs

If the transmission has undergone major repairs or rebuilds in the past, its lifespan can be impacted depending on the quality of the repairs and the use after the repairs.

With that said, here’s a general estimation:

• Under ideal conditions, including regular maintenance, moderate driving habits, and no towing, a 68RFE could reach 150,000 to 200,000 miles.
• However, it’s not uncommon for these transmissions to experience problems much earlier, between 50,000 and 100,000 miles, especially if not properly maintained or heavily used.

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How do I strengthen my 68RFE?

There are several ways to strengthen your 68RFE transmission, depending on your budget and performance goals. Here are some of the most common and effective methods:

• Upgrade the valve body and solenoid pack

The valve body is the brain of the transmission, and the solenoid pack controls the fluid flow and pressure. Upgrading these components can improve the shift quality, responsiveness, and durability of the 68RFE. You can watch a video on how to do this here.

• Install a shift kit

A shift kit is a set of springs, valves, and other parts that modify the hydraulic circuits of the transmission. A shift kit can increase the line pressure, reduce the shift time, and prevent slippage and wear of the clutch packs. You can learn more about how to install a shift kit here.

• Replace the torque converter

The torque converter is the link between the engine and the transmission, and it transfers the torque and power to the wheels. Replacing the stock torque converter with a higher-stall, lower-slip, or lockup converter can improve the acceleration, efficiency, and longevity of the 68RFE. You can read more about the benefits of a new torque converter here.

• Add an auxiliary cooler

The 68RFE transmission generates a lot of heat, especially under heavy loads or high speeds. Excessive heat can damage the seals, clutches, and electronics of the transmission. Adding an auxiliary cooler can lower the fluid temperature and extend the life of the 68RFE. You can find out how to add an auxiliary cooler here.

• Replace the transmission with a 4R package

If you want the ultimate upgrade for your 68RFE, you can replace it with a 4R package from ATS Diesel. This is a custom-built transmission that uses a four-speed planetary gear set, a billet input shaft, a triple-disc torque converter, and a standalone controller. The 4R package can handle up to 1500 hp and provide smooth and reliable shifts. You can learn more about the 4R package here.

How do I get more power out of my Cummins?

Modifying your Cummins engine for increased power can be risky and complex. While options like performance injectors, turbochargers, or ECU remapping exist, these modifications can negatively impact reliability, fuel efficiency, and legality. 

It’s strongly recommended to consult a qualified diesel mechanic who can assess your specific needs and advise you on safe and reliable methods to enhance your engine’s performance. This can include optimizing maintenance, addressing any existing issues, and exploring manufacturer-approved upgrades.

Is the Aisin transmission better than 68RFE?

Yes, the Aisin transmission is generally considered better than the 68RFE in most aspects, especially for heavy-duty use or performance. Here’s a breakdown of the key differences:

Strengths of Aisin

• Higher Torque Capacity: The Aisin typically boasts a higher torque capacity compared to the 68RFE, making it better suited for towing heavy loads and high-performance applications.
• Stronger Build: The Aisin generally has a more robust design and stronger components, contributing to its greater reliability and longer lifespan compared to the 68RFE.
• Smoother Shifting: The Aisin is known for smoother and more responsive shifting, enhancing the driving experience.

Weaknesses of Aisin

• Higher Cost: The Aisin is generally more expensive to purchase and maintain compared to the 68RFE.
• Less Availability: The Aisin is found in fewer vehicle models compared to the 68RFE, potentially limiting its accessibility.
• Limited Aftermarket Support: Compared to the 68RFE, the Aisin might have less readily available aftermarket parts and modification options.

Therefore, the choice between the two depends on your priorities:

Aisin is the better option if you:

• Prioritize towing and hauling heavy loads.
• Value reliability and durability.
• Desire a smoother and more responsive driving experience.

However, the 68RFE might be a more suitable choice if:

• Cost is a major concern.
• You don’t frequently tow or haul heavy loads.
• You value accessibility and readily available parts.

What kind of fluid does a 68RFE take?

The 68RFE transmission is designed to use ATF +4 fluid, which is a synthetic automatic transmission fluid that meets the Mopar standards. The brand of the fluid does not matter as long as it is a licensed ATF +4 product.

What is the difference between 48RE and 68RFE?

The 48RE and the 68RFE are two different types of automatic transmissions that are used in Dodge Ram trucks. The main differences between them are:

• The 48RE is a four-speed transmission that was introduced in 2003 and was paired with the 5.9L Cummins diesel engine. The 68RFE is a six-speed transmission that was introduced in 2007 and was paired with the 6.7L Cummins diesel engine.
• The 48RE is based on the older TorqueFlite design, while the 68RFE is based on the newer RFE design. The RFE design features three planetary gearsets, three multiple-disc input clutches, three multiple-disc holding clutches, and a dual internal filter system. The 68RFE also has revised gear ratios and transmission controller programming for larger applications.
• The 48RE is considered to be stronger and more reliable than the 68RFE, as it can handle more torque and power with proper upgrades. The 68RFE is more prone to failure due to its weaker hard parts, such as stamped steel, thin, and aluminum drums. The 68RFE also generates more heat and requires more cooling than the 48RE.
• The 48RE can be replaced with a custom-built 4R package from ATS Diesel, which uses a four-speed planetary gearset, a billet input shaft, a triple-disc torque converter, and a standalone controller. The 4R package can handle up to 1500 hp and provide smooth and reliable shifts. The 68RFE does not have a similar upgrade option available.

How many gears does a 68RFE have?

The 68RFE is a six-speed automatic transmission that is used in Dodge Ram trucks with the 6.7L Cummins diesel engine. It has three planetary gear sets, three multiple-disc input clutches, three multiple-disc holding clutches, and a dual internal filter system. The gear ratios are:

• 1st: 3.23:1

• 2nd: 1.83:1

• 3rd: 1.41:1

• 4th: 1.00:1

• 5th: 0.81:1

• 6th: 0.62:1

• Reverse: 4.44:1

What brand is the 68RFE transmission?

The 68RFE transmission is a six-speed automatic transmission made by Chrysler. It was developed in 2007 for use in Dodge Ram trucks with the 6.7L Cummins diesel engine. It is based on the RFE design, which features three planetary gear sets, three multiple-disc input clutches, three multiple-disc holding clutches, and a dual internal filter system.

How To Relearn 68RFE Transmission?

The relearning process for a 68RFE transmission can be approached in two ways:

1. Using a scan tool

This method is quick and precise but requires specialized equipment.

Requirements

A scan tool capable of accessing the Transmission Control Module (TCM) of your Dodge Ram. These can be expensive for individuals but are readily available at repair shops.

Process

• Connect the scan tool to your vehicle’s OBD-II port.
• Navigate to the “Transmission” or “Powertrain” section in the scan tool’s menu.
• Look for an option like “Quick Learn” or “Adaptive Learn” related to the transmission.
• Follow the on-screen prompts provided by the scan tool, which typically involve shifting through gears in a specific sequence while keeping your foot on the brake.
• Once the process is complete, the scan tool will notify you.

2. Manual driving relearn

This method is free and accessible but requires more effort and doesn’t guarantee complete accuracy.

Process

• Find a quiet, safe area with minimal traffic.
• Ensure your engine is warm and at operating temperature.
• Shift into Drive (D) and come to a complete stop.
• Gently accelerate to around 25 mph and hold it steady for 10 seconds.
• Shift to Neutral (N) and hold it for 10 seconds.
• Repeat steps 2 to 4, gradually increasing your speed to 50 mph and then back down to 25 mph in increments of 10 mph.
• After completing the speed variations, shift to Park (P) and turn off the engine.
• Let the vehicle sit for 2 minutes, then restart and drive normally.

68RFE Transmission Upgrades

Upgrading your 68RFE transmission can improve its performance, reliability, and lifespan, but it’s important to weigh the potential benefits, risks, and costs involved. Here’s an overview of common 68RFE upgrades:

Benefits

• Improved Performance: Upgrades like torque converter upgrades can offer faster acceleration and better towing capability.
• Increased Reliability: Stronger components can enhance durability and reduce the risk of premature failure, especially with heavier use.
• Enhanced Drivability: Smoother shifts and improved responsiveness can enhance the driving experience.

Risks

• Warranty Voiding: Unauthorized modifications might void your vehicle’s powertrain warranty.
• Increased Cost: Upgrading can be expensive, with individual parts and labor costs varying significantly.
• Potential for Issues: Improper installation or incompatible parts can lead to further problems with the transmission.

Common 68RFE Upgrades

1. Torque Converter: Upgrading to a higher stall torque converter can improve acceleration and towing performance, but can also decrease fuel efficiency.
2. Valve Body: Replacing the valve body with a performance or upgraded version can address common issues like cross-leaks and improve shift performance.
3. Clutch Packs: Replacing worn or burnt clutch packs with stronger aftermarket options can enhance torque handling and durability.
4. Solenoids and Sensors: Replacing faulty solenoids and sensors can restore proper transmission operation and address shifting issues.
5. Transmission Cooler: Adding a larger or more efficient transmission cooler can improve heat dissipation and help prevent overheating, especially under heavy loads.

What Is The 68RFE Transmission Rebuild Cost?

The 68RFE transmission rebuild cost can vary depending on the type and extent of the upgrade you want to do. The average range is from $4500 to $7500 for a performance rebuild with upgraded parts and a new torque converter. 

However, some custom-built transmissions or complete replacements can cost much more, up to $20,000 or more for a 4R package or an Allison swap. The labor, core, and shipping charges are also additional expenses that you need to factor in. 

Conclusion

The 68RFE transmission, while offering a respectable towing capacity and being readily available in popular Dodge Ram trucks, is known for having reliability issues. Understanding its strengths and weaknesses, along with proper maintenance and potential upgrades, can help you extend its lifespan and optimize its performance.

Key Points:

• The 68RFE is a 6-speed automatic transmission found in Dodge Ram trucks with 6.7L Cummins engines.
• It has known issues with valve body leakage, burnt overdrive clutches, and high-pressure oil pump wear, leading to slipping, harsh shifting, and potential failure.
• Regular maintenance with the correct fluid type, avoiding excessive towing or aggressive driving, and seeking professional help for repairs is crucial for its longevity.
• While not ideal for heavy towing or demanding applications, it can be a suitable option for casual drivers or those who tow moderately, prioritizing affordability and readily available parts.
• Upgrading the valve body, solenoid pack, torque converter, or adding an auxiliary cooler can improve performance and durability, but involves weighing the benefits, costs, and potential warranty implications.