Transmission fluid thermal bypass valve for Hemi Cummins Ram 2500 3500
Transmission fluid thermal bypass valve front view
Transmission fluid thermal bypass valve installation kit
Transmission fluid thermal bypass valve included parts
EGR Performance transmission fluid thermal bypass valve
Transmission fluid thermal bypass valve for Hemi Cummins Ram 2500 3500
Transmission fluid thermal bypass valve front view
Transmission fluid thermal bypass valve installation kit
Transmission fluid thermal bypass valve included parts
EGR Performance transmission fluid thermal bypass valve

Transmission Fluid Thermal Bypass Valve for 5.7L/6.4L Hemi & 6.7L Cummins Ram 2500 3500 (2019-2024)

$67.59
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Details
Ram 2500/3500 transmission bypass valve in stock. Fits 2019-2024 5.7L/6.4L/6.7L trucks.
Direct-fit thermal bypass valve for Ram 2500/3500 Hemi & Cummins. Restores cooler flow, cuts trans temps towing. Local USA stock, ready to ship.

Fitment Table

Brand
Model
Year
Engine Model
Ram
2500
2019-2024
5.7L Hemi V8
Ram
2500
2019-2024
6.4L Hemi V8
Ram
2500
2019-2024
6.7L Cummins Turbo Diesel I6
Ram
3500
2019-2024
5.7L Hemi V8
Ram
3500
2019-2024
6.4L Hemi V8
Ram
3500
2019-2024
6.7L Cummins Turbo Diesel I6
✅ Exact Fitment Guarantee | If you are unsure about compatibility, please contact us at service@egrperformance.com with your VIN number.
Shipping Details

Ontario CA / Springdale OH / Newark NJ
Package List
  • 1x Transmission Fluid Thermal Bypass Valve with serviceable neodymium magnetic plug (pre-installed)
Delivery Time

2-5 working days inland in the United States
Attention
Legal Disclaimer EGR DPF Delete Offroad Use Only

LEGAL DISCLAIMER

This product may NEVER be installed on a vehicle registered for highway or public street use. By installing this product onto your vehicle, you assume all risk and liability associated with its use. It is your responsibility to make sure your vehicle complies with all federal, state, and local emissions laws.

Federal and many state and local laws prohibit the removal, modification or rendering inoperative of any part of the design affecting emissions or safety on motor vehicles used on a public street or highway. Violation may result in a fine of up to $32,500 per vehicle (or possibly higher depending on changes in the law). All civil penalties and fines for removing your vehicle's emissions equipment are the sole responsibility of the end user.

No other applications besides off-road competition racing use are intended or implied. Depending on where you live, additional restrictions may apply. Check all applicable laws before installing or using.

Not available for sale or use in the state of California, Colorado and Arizona.

Product details

The Transmission Fluid Thermal Bypass Valve is a direct-fit cooling upgrade built for 2019-2024 Ram 2500 and 3500 trucks equipped with the 5.7L Hemi V8, 6.4L Hemi V8, or 6.7L Cummins Turbo Diesel I6. The factory plastic thermostatic valve restricts fluid flow to the transmission cooler — even when fully open — which allows heat to build up fast during fifth-wheel towing, heavy hauling, and sustained highway grades. This billet aluminum replacement removes that restriction completely, giving your 66RFE, 68RFE, or Aisin AS69RC transmission uninterrupted cooler flow at all times. The result is lower operating temperatures, firmer shifts under load, and real protection against clutch and gear damage that sends diesel truck owners to the transmission shop. A built-in serviceable neodymium magnet also traps ferrous debris before it circulates through the cooler and internal components. It installs in roughly 30 minutes with basic hand tools — no tuning, cutting, or drilling required. Keep reading for full fitment details, specifications, installation steps, maintenance guidance, and answers to the most common questions from Ram owners.

Product Overview

  • The Transmission Fluid Thermal Bypass Valve replaces the restrictive factory thermostatic valve on 2019-2024 Ram 2500 and 3500 trucks.
  • The OEM plastic valve limits cooler flow even when open, causing transmission temperatures to climb under load.
  • This valve routes fluid to the cooler with zero restriction at all times, so heat is removed continuously instead of being held in the system.
  • Machined from 6061-T6 billet aluminum, it eliminates the cracking and leaking failures common to the plastic OEM part.
  • A built-in neodymium magnet captures metal debris, protecting the 66RFE, 68RFE, and Aisin AS69RC transmissions from abrasive wear.

Ideal For

  • Towing and Hauling: Keeps transmission temperatures in check while pulling fifth wheels, goosenecks, equipment trailers, and max payloads — the situation where Ram trucks generate the most heat.
  • Daily Driving: Delivers consistent cooler flow from the first mile, so the transmission reaches a stable operating range and shifts cleanly in stop-and-go traffic and highway cruising.
  • Off-Road Use: Maintains cooling during low-speed, high-load trail and worksite driving where airflow through the cooler is limited.
  • Commercial Vehicles: Protects work trucks that plow, tow, or run loaded routes day after day, reducing the risk of expensive transmission downtime.
  • Engine Performance Upgrades: Pairs naturally with tuning, exhaust, intake, and other Ram performance upgrades by protecting the transmission that has to handle the extra output.
  • Long-Term Vehicle Ownership: Replaces a known plastic failure point with a serviceable billet part and magnetic debris protection, lowering the odds of a four-figure transmission rebuild.

Core Advantages

  • Increased Horsepower and Torque: This valve does not add crank horsepower on its own; by preventing heat soak and clutch slippage, it helps your Hemi or Cummins put its full power to the ground consistently, especially while towing.
  • Improved Fuel Efficiency: No MPG figure is claimed, but cooler, stable transmission fluid reduces converter slip and parasitic drag, helping the truck maintain its normal efficiency on long loaded runs.
  • Reduced Engine Temperature: Unrestricted fluid flow to the cooler significantly lowers transmission operating temperatures, which also reduces heat transferred back to the radiator and cooling system.
  • Extended Engine Life: Lower transmission heat and the built-in debris magnet protect gears, clutches, seals, and the cooler from heat damage and abrasive metal particles.
  • Direct Bolt-On Installation: OEM-machined fitment for the factory location — no modifications, cutting, or drilling, and typically installed in under 30 minutes.
  • All-In-One Kit: The valve arrives complete with the serviceable magnetic plug pre-installed, so no extra parts are needed for a standard installation.

Technical Specifications

  • Material: 6061-T6 billet aluminum body; high-temperature neodymium magnetic service plug
  • Finish: Precision CNC-machined, anodized billet finish
  • Weight: Approx. 1.2 lb (0.54 kg)
  • Dimensions: Approx. 3.5 x 2.5 x 2.0 in (8.9 x 6.4 x 5.1 cm)
  • Compatible Transmissions: 66RFE, 68RFE, Aisin AS69RC automatic transmissions
  • Fitment: 2019-2024 Ram 2500 / 3500 — 5.7L Hemi V8, 6.4L Hemi V8, 6.7L Cummins Turbo Diesel I6
  • Warranty: 1 Year Limited Warranty against manufacturing defects

Why Choose EGR Performance

  • Premium Quality Materials: 6061-T6 billet aluminum replaces the failure-prone OEM plastic housing for far greater strength and corrosion resistance.
  • Precision Engineering: CNC-machined to exact OEM dimensions for a leak-free, drop-in fit on every listed Ram application.
  • Rigorous Testing: Parts are validated for fitment, sealing, and heat cycling under real-world towing and heavy-duty conditions.
  • Dedicated Customer Support: Email us at service@egrperformance.com for fitment help, installation questions, and VIN verification.
  • Fast Shipping from USA Warehouse: In-stock orders ship quickly from US-based warehouses, so your truck spends less time off the road.
  • 1 Year Limited Warranty: Every valve is covered against manufacturing defects for one year from purchase.

Troubleshooting and Problem Solving

Common Issues After Installation

  • Check Engine Light
  • Rough or Harsh Shifts
  • Reduced Power / Limp Mode
  • Transmission Fluid Leaks at line connections
  • Persistent High Transmission Temperatures

Error Code Solutions

  • P0218 (Transmission Fluid Overtemperature): Usually indicates low fluid level, a pinched cooler line, or air in the system. Check the fluid level, verify line routing, and confirm the valve is installed in the correct flow direction.
  • P0700 (Transmission Control System Malfunction): A generic request code stored alongside a transmission fault. Scan the TCM for the accompanying code, clear it after verifying fluid level and connections, and retest.
  • P0741 (Torque Converter Clutch Circuit Performance / Stuck Off): Often triggered by overheated or low fluid. Top off to the correct level, clear the code, and test-drive; if it returns, inspect the cooler lines for blockage or leaks.

How to Reset Check Engine Light After Installation

  1. Confirm the installation is complete, all lines are secured, and the transmission fluid is at the correct level.
  2. Connect an OBD2 scanner (or use a compatible diagnostic tool) and read all stored codes to rule out an underlying issue.
  3. Clear the codes with the scanner; the light may also clear on its own after several normal drive cycles if no fault remains.
  4. If the light returns immediately, do not keep clearing it — inspect the installation and contact technical support.

What to Do If Your Vehicle Loses Power After Installation

  • Pull over safely and check for transmission fluid leaks under the truck.
  • Verify the fluid level immediately; a low level from spillage can cause limp mode and poor shifting.
  • Inspect cooler lines for kinks, loose fittings, or cross-threaded connections.
  • Confirm the valve orientation matches the factory flow direction.
  • Scan for stored codes and contact service@egrperformance.com if the issue persists.

Long-Term Maintenance Tips

  • Regular Inspection: Every 5,000-10,000 miles, inspect the valve and line fittings for seepage, loose hardware, or corrosion, especially after heavy towing.
  • Routine Maintenance: At each transmission fluid service, remove the serviceable magnetic plug, wipe off collected ferrous debris, and reinstall with a clean seal.
  • Wear Parts Replacement: Inspect the plug seal and cooler-line O-rings during every fluid change and replace any hardened or cracked seals immediately.
  • Hardware Check: Every 10,000 miles, confirm mounting hardware and line fittings remain torqued to spec and that no lines are rubbing or chaffing.
  • Storage Tips: If the truck is stored long-term, leave the transmission at the correct fluid level and run the engine through its gear ranges periodically to keep seals lubricated.
  • Warranty Reminder: "Following these maintenance guidelines will keep your 1 Year Limited Warranty valid."

This Transmission Fluid Thermal Bypass Valve is a direct replacement for 2019, 2020, 2021, 2022, 2023, and 2024 Ram 2500 and Ram 3500 trucks. It covers the 5.7L Hemi V8 and 6.4L Hemi V8 gasoline engines as well as the 6.7L Cummins Turbo Diesel I6, and works with the 66RFE, 68RFE, and Aisin AS69RC automatic transmissions.

  • No modifications, custom lines, adapters, or tuning are required for any listed application.
  • Exceptions: Does not fit 2025 and newer Ram 6.7L Cummins models. Does not fit Ram 1500, Ram 1500 Classic, or manual-transmission trucks. Always confirm your transmission type before ordering.
  • If your truck has aftermarket cooler lines or a modified cooling setup, verify clearance and fitting size before purchase.

For 100% fitment confirmation, please send your VIN number to service@egrperformance.com.

  1. Dispatch Time: Orders will be shipped within 24 hours after successful payment.
  2. Delivery Time: 2-5 business days after dispatch (delivery speed depends on proximity to warehouse location).
  3. Return Window:7 days for unsatisfactory items45 days for quality-related issues
  4. Refund Processing: Refunds will be processed back to your original payment method within 2-4 business days after receiving the automated refund confirmation email (subject to bank verification).

What is a transmission fluid thermal bypass valve?

It is a valve that controls how transmission fluid is routed to the cooler. The factory version uses a thermostat that restricts flow, while this billet replacement allows full, unrestricted flow to the cooler at all times.

How does a transmission fluid thermal bypass valve work?

The factory valve delays or limits cooler flow based on temperature, trapping heat during hard use. This replacement removes the restriction, so fluid travels to the cooler continuously and heat is removed before it builds up.

What are the benefits of a transmission fluid thermal bypass valve?

The main benefits are lower transmission temperatures, firmer shifts under load, protection against clutch and gear damage, and a billet housing that will not crack like the OEM plastic part. The built-in magnet also captures metal debris.

Will a transmission fluid thermal bypass valve void my warranty?

Installing an aftermarket part does not automatically void a vehicle warranty, though damage caused by improper installation is not covered. Our valve itself carries a 1 Year Limited Warranty against manufacturing defects.

Is a transmission fluid thermal bypass valve legal in my state?

This is a cooling-system replacement part and does not modify emissions controls, so it is generally legal for street use in all 50 states. Always confirm current local regulations for your specific application.

Do I need a tuner for a transmission fluid thermal bypass valve?

No. The valve is a purely mechanical drop-in part and requires no tuning, programmer, or ECU changes. It works with both stock and tuned trucks.

How much horsepower does a transmission fluid thermal bypass valve add?

It does not add advertised horsepower. Instead, it prevents heat-related clutch slip and power loss, so your Hemi or Cummins delivers its existing power more consistently, especially while towing.

How much MPG gain can I expect from a transmission fluid thermal bypass valve?

No fixed MPG gain should be expected. By reducing converter slip and heat-related drag, the valve helps the truck maintain its normal efficiency, but results vary with load, driving style, and condition.

How long does it take to install a transmission fluid thermal bypass valve?

Most installations take about 30 minutes with basic hand tools. Add time if you are also performing a full fluid and filter service.

Can I install a transmission fluid thermal bypass valve myself?

Yes, if you are comfortable working around transmission cooler lines and have basic hand tools. No printed instructions are included, so professional installation is recommended if you have any doubts.

How often should I maintain my transmission fluid thermal bypass valve?

Inspect the valve and fittings every 5,000-10,000 miles, and clean the magnetic plug at each scheduled transmission fluid service. Replace any hardened seals or O-rings as needed.

Will this transmission fluid thermal bypass valve fit my 2022 Ram 2500 6.7L Cummins?

Yes. It fits every 2019-2024 Ram 2500 and 3500 with the 6.7L Cummins and 68RFE or Aisin AS69RC transmission. Send us your VIN if you want exact confirmation before ordering.

What is the warranty on this transmission fluid thermal bypass valve?

It includes a 1 Year Limited Warranty covering manufacturing defects. Damage from misuse, accidents, or improper installation is not covered.

Do you offer technical support?

Yes. Email service@egrperformance.com any time for fitment help, installation questions, or troubleshooting, and include your VIN and order number when possible.

How long does shipping take?

Orders ship fast from our USA warehouse, typically within 1-2 business days. Domestic transit usually takes 2-5 business days depending on your location.

Can I return this transmission fluid thermal bypass valve if it doesn't fit?

Yes, unused items in original condition can be returned within our standard return window. Contact us first with your order number, and we will help confirm fitment or arrange the return.

Installation Difficulty Level

Easy

Estimated Installation Time

Approx. 30 minutes (0.5 hour)

Required Tools

  • Socket Set
  • Torque Wrench
  • Screwdrivers
  • Pliers
  • Drain Pan
  • Shop Towels / Rags
  • Replacement Transmission Fluid (to top off after service)

Step-by-Step Installation Overview (3-5 Core Steps)

  1. Let the truck cool completely, then locate the factory thermal bypass valve at the transmission cooler line and place a drain pan underneath.
  2. Remove any retaining hardware and disconnect the factory valve, allowing residual fluid to drain.
  3. Install the new Transmission Fluid Thermal Bypass Valve in the factory position, reconnect the cooler lines, and torque hardware to spec.
  4. Top off the transmission with the correct fluid, then start the engine and inspect every connection for leaks while shifting through the gear ranges.
  5. Confirm fluid level at operating temperature and take a short test drive to verify normal shifting and cooler flow. No ECU reset or tuning is required for this part.

Important Note: No printed installation instructions are included. Professional installation is highly recommended. If you need technical support, please contact us at service@egrperformance.com.