If you tow heavy loads or push your diesel truck hard, you know the transmission is the weak link. Heat and factory flaws can cut its life short. This guide reviews top upgrades that fix common 68RFE and AS69RC issues.
You will learn about thermal bypass valves that improve cooling, steel filter screws that prevent failures, and electronics kits that sharpen shifting. Each pick is chosen for real-world towing reliability.
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RevMax 68RFE Thermal Bypass Valve Transmission Thermostat Cooler Bypass Kit…
Best forImmediate cooling flow boost
- Eliminates factory restriction
- Billet aluminum with cooling fins
ConsiderRequires basic wrench skills
Sporthfish 68RFE Transmission Spin On Filter Screw Steel Upgrade for 2007-2…
Best forPreventing filter drop failures
- Strong steel construction
- OEM size, perfect fit
ConsiderNo extra filter included
68RFE Transmission Spin On Filter Screw Steel Upgrade for 2007.5-2021 Ram 2…
Best forRust-free long-term durability
- Stainless steel, never rusts
- Reusable and cost-saving
ConsiderNo gasket included
BD Diesel 1060605 Transmission Valve Body Electronics Upgrade Kit; Incl. Pr…
Best forFirmer, consistent shift feel
- Improves line pressure stability
- Metal transducer for durability
ConsiderRequires mechanical expertise
Transmission Cooler Thermostatic Bypass Valve Upgrade Fit for 2013 2014 201…
Best forHot climate towing performance
- Eliminates orifice restriction
- Billet aluminum construction
ConsiderOnly fits 2013-2018 models
ATS Diesel – 68RFE / AS69RC Thermal Bypass Valve Up-Grade (3100052392)
Best forProven brand reliability
- Trusted ATS brand
- Fits 68RFE and AS69RC
ConsiderNo detailed specs listed
Transmission Thermal Bypass Valve Thermostat Cooler Upgrade Kit Compatible …
Best forDual transmission compatibility
- Fits 68RFE and AS69RC
- Billet aluminum build
ConsiderNo instructions included
68RFE / AS69RC Transmission Cooler Thermostatic Bypass Upgrade For 2013-201…
Best forImmediate temperature reduction
- Allows immediate cooling
- Corrosion-resistant aluminum
ConsiderNo gaskets or O-rings
SPELAB Transmission Thermal Bypass Valve Thermostat Cooler Upgrade Kit
Best forNewer Ram models 2019-2024
- Fits latest Ram models
- Billet aluminum durability
ConsiderOnly for 2019-2024 trucks
Thermal Bypass Valve Upgrade with Billet Filter Coupler Compatible with 201…
Best forComplete cooling and filter fix
- Includes billet filter coupler
- Direct bolt-on, no cutting
ConsiderOnly for 2019-2024 models
RevMax 68RFE Thermal Bypass Valve – Cooler Flow Fix
Brand: Piping Hot Art Works
A reliable cooling upgrade that extends transmission life for towing.
This kit from Piping Hot Art Works removes the factory bypass valve restriction that blocks cooler flow when the fluid is cold. That means your transmission gets full cooling from the moment you start the engine, which is a huge win for towing in stop-and-go traffic or on long grades.
The billet 6061 aluminum body with integrated cooling fins helps dissipate heat, and the included O-rings and clips make installation straightforward. You can also flush your cooler lines with room-temperature fluid, saving you from expensive hot flush services. It is a smart, durable upgrade for any 2013-2018 Ram 6.7L Cummins.
- Eliminates factory restriction
- Billet aluminum with cooling fins
- Easy DIY flush capability
- Requires basic wrench skills
- Only fits 2013-2018 models
Sporthfish 68RFE Steel Filter Screw – Durable Replacement
Brand: Sporthfish
A must-have cheap fix to avoid a costly transmission failure.
The factory plastic filter screw on your 68RFE can crack or strip, risking the filter falling off and causing catastrophic damage. Sporthfish replaces it with a CNC-machined steel version that is strong and worry-free. It fits 2007.5-2021 Ram 2500 and 3500 trucks with the 6.7L Cummins.
Installation is simple: use a 1/2-inch wrench to remove the old plastic screw and thread in this steel one. The OEM-size design ensures a perfect fit, and the upgraded material prevents breaking and falling off. It is a cheap, essential upgrade for anyone who tows or off-roads.
- Strong steel construction
- OEM size, perfect fit
- Simple 1/2-inch wrench install
- No extra filter included
- Limited to 68RFE models
Yoursme Stainless Steel Filter Screw – Rust-Free Upgrade
Yoursme offers a stainless steel filter screw that never rusts and won’t degrade like the factory plastic piece. It is precision CNC machined to OEM specs, so it fits 2007.5-2021 Ram 2500 and 3500 trucks with the 6.7L Cummins perfectly. The tool-friendly design lets you install it with a simple 1/2-inch wrench.
Unlike single-use plastic connectors that warp or crack, this screw is reusable and cost-saving. You can swap it between filter changes without worry. It is a small upgrade that gives you peace of mind, especially if you tow in harsh conditions.
- Stainless steel, never rusts
- Reusable and cost-saving
- Precision CNC machined
- No gasket included
- Only for 68RFE transmissions
BD Diesel Valve Body Electronics Kit – Shift Control
Brand: BD DIESEL
A solid electronics upgrade for sharper, more reliable shifts.
BD Diesel’s electronics upgrade kit enhances your 68RFE valve body performance by replacing weak factory components. It includes a pressure transducer adapter and clip for a metal transducer, plus a governor body gasket. This kit helps maintain consistent line pressure, which is critical for firm, reliable shifts under load.
If you’ve noticed soft or delayed shifts when towing, this kit addresses the root cause. The metal transducer is more durable than the plastic factory unit, and the adapter ensures a secure fit. It is a professional-grade upgrade for serious diesel owners.
- Improves line pressure stability
- Metal transducer for durability
- Includes necessary gasket
- Requires mechanical expertise
- Price may be higher than others
FQRANBO Thermal Bypass Valve – 2013-2018 Fit
FQRANBO’s thermal bypass valve is designed for 2013-2018 Ram 2500 and 3500 trucks with the 68RFE and 6.7L Cummins. It eliminates the orifice restriction that limits cooler flow, helping your transmission maintain a higher heat exchanger temperature. This keeps the fluid at an optimal range, reducing wear.
Made from billet 6061 aluminum, it is sturdy and corrosion-resistant. The direct bolt-on design means you don’t need to cut any lines, making installation straightforward. It is a practical upgrade for towing in hot climates.
- Eliminates orifice restriction
- Billet aluminum construction
- Direct bolt-on, no cutting
- Only fits 2013-2018 models
- No extra hardware included
ATS Diesel Thermal Bypass Valve – Proven Performance
Brand: ATS Diesel Performance
A quality bypass valve from a reputable diesel performance brand.
ATS Diesel Performance is a trusted name in diesel upgrades, and their thermal bypass valve for 68RFE and AS69RC transmissions lives up to that reputation. It eliminates the factory bypass valve, which is known to restrict cooler flow and cause overheating. This simple swap keeps your transmission temperatures in check.
The kit is designed for easy installation, and it works with both 68RFE and Aisin AS69RC transmissions. If you tow heavy trailers or drive in mountainous terrain, this valve helps prevent heat-related failures. It is a reliable, no-nonsense upgrade.
- Trusted ATS brand
- Fits 68RFE and AS69RC
- Effective temperature control
- No detailed specs listed
- May be pricier than generic
SPELAB Thermal Bypass Valve – 2013-2018 Kit
SPELAB’s thermal bypass valve upgrade is compatible with 2013-2018 Ram 2500 and 3500 trucks with 6.7L Cummins and either 68RFE or Aisin AS69RC transmissions. It addresses the factory valve’s delayed cooler circulation, which can lead to excessive heat. By allowing consistent fluid flow, it helps manage heat and extends transmission life.
The kit is machined from durable 6061 aluminum, ensuring strength and longevity. It is a direct replacement, so you can install it without special tools. For towing enthusiasts, this is a smart investment to protect your transmission.
- Fits 68RFE and AS69RC
- Billet aluminum build
- Improves cooling efficiency
- No instructions included
- May require basic mechanical skill
RJSPHH Thermal Bypass Valve – Quick Cooling
RJSPHH’s thermal bypass valve is designed for 2013-2018 Dodge Ram 6.7L Cummins with 68RFE or Aisin AS69RC transmissions. It removes the factory limitation that reduces most cooler flow, allowing your cooler to cool the transmission immediately. This means lower operating temperatures and longer transmission life, especially under heavy towing.
The valve is made of high-quality aluminum with strong corrosion and aging resistance. It is a direct replacement that installs easily. If you want a simple way to keep your transmission cool, this is a solid choice.
- Allows immediate cooling
- Corrosion-resistant aluminum
- Easy direct replacement
- No gaskets or O-rings
- Limited to 2013-2018 models
SPELAB Thermal Bypass Valve – 2019-2024 Kit
This SPELAB kit is tailored for 2019-2024 Ram 2500 and 3500 trucks with 6.7L Cummins and 68RFE or AS69RC transmissions. It fixes the factory bypass valve’s tendency to delay cooler flow, which can cause heat buildup during towing. By ensuring consistent circulation, it helps prevent fluid breakdown and component wear.
Constructed from high-grade billet aluminum, it offers dependable strength and durability. The kit is a direct bolt-on, so installation is hassle-free. For owners of newer Rams, this is a valuable upgrade to protect your investment.
- Fits latest Ram models
- Billet aluminum durability
- Prevents fluid breakdown
- Only for 2019-2024 trucks
- No hardware included
FQRANBO Bypass Valve with Filter Coupler – 2019-on
Brand: FQRANBO
A comprehensive upgrade that improves cooling and filter security.
FQRANBO’s thermal bypass valve upgrade is compatible with 2019-2024 Ram 6.7L Cummins with 68RFE or Aisin AS69RC transmissions. It eliminates the factory bypass valve’s flow restriction, which can cause overheating. The kit also includes a billet filter coupler, replacing the weak plastic one for added reliability.
Installation is easy: disconnect the old line and install the new thermostatic valve without cutting anything. The aluminum alloy construction is sturdy and corrosion-resistant. This combo addresses two common failure points in one package.
- Includes billet filter coupler
- Direct bolt-on, no cutting
- Corrosion-resistant aluminum
- Only for 2019-2024 models
- May be overkill for light use
Buyer’s Guide: What to Consider
Choosing the right transmission upgrade depends on your truck’s model, your towing habits, and the weak points you want to fix. This guide breaks down key factors to help you decide.
- Transmission Compatibility: Ensure the upgrade fits your specific transmission type, such as 68RFE or Aisin AS69RC, and your truck's model year. Some kits are year-specific, so double-check before purchasing.
- Cooling Efficiency: Thermal bypass valves improve cooling by removing factory restrictions. Look for designs that allow immediate fluid flow to the cooler, reducing heat buildup during heavy towing.
- Material Quality: Choose upgrades made from durable materials like billet 6061 aluminum or stainless steel. These resist corrosion and withstand high temperatures, ensuring long-term reliability.
- Ease of Installation: Many upgrades are direct bolt-ons that require no cutting or special tools. Consider your mechanical skill level and whether the kit includes necessary hardware or instructions.
- Additional Features: Some kits include extras like filter couplers or gaskets. These can address multiple weak points at once, offering better value and more comprehensive protection.
Conclusion
Upgrading your diesel transmission is essential for towing reliability. Thermal bypass valves improve cooling, steel filter screws prevent failures, and electronics kits sharpen shifts. Each product in this list targets a specific issue, so pick based on your truck’s needs.
For most owners, a thermal bypass valve is the first step, followed by a steel filter screw for peace of mind. If you have a newer Ram, consider the SPELAB or FQRANBO kits. For older models, RevMax or ATS are solid choices. Invest in these upgrades to protect your transmission and enjoy worry-free towing.
Erica Steven is the founder and lead writer of WorstBrands, a site dedicated to providing honest and trustworthy reviews about outdoor gear and fashion products.
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