Randys Transmission 03-09 Dodge 5.9L Cummins 48RE | 68RFE Randy's Fluidyne Extreme Duty Bar Plate Transmission Cooler

The RT-48-0309BP is an Extreme Duty Bar & Plate transmission cooler built for 2003-2009 Dodge Ram 2500 and 3500 trucks running the 5.9L or 6.7L Cummins with the 48RE or 68RFE transmission. This bar and plate core steps up from the factory-style cooler with a dual-pass aluminum design built for tow rigs, work trucks, and high-horsepower builds that run hotter than a stock cooler was ever designed to handle.

The RT-48-0309BP is a bar and plate transmission cooler for 2003-2009 Ram 2500/3500 5.9L and 6.7L Cummins trucks with the 48RE or 68RFE transmission, using a dual-pass core and -8AN O-ring inlet and outlet fittings.

Stock Cooler or the Extreme Duty Upgrade?

Upgrade to the RT-48-0309BP if your truck tows heavy, hauls daily, or puts real power through the 48RE or 68RFE. Stay with a stock-style cooler if your truck is lightly loaded and the factory unit has kept up so far. The bar and plate core carries 4X the fluid capacity of the stock cooler, giving the transmission more room to shed heat before it ever reaches a danger zone. If your transmission and fitment match the checks above, this is the cooler to add to your build list.

What Makes This Cooler Extreme Duty

The bar and plate core rejects heat more effectively than a stock tube-and-fin design, and the dual-pass flow routes fluid through the core twice instead of once before it returns to the transmission. That second pass keeps fluid in contact with cooling airflow longer, which helps hold down transmission temperature during long grades, heavy trailers, or sustained high-torque runs.

• Aerospace-grade aluminum construction for extreme-temperature durability.
• Internally and externally TIG welded, not crimped, for leak resistance under pressure.
• Heat-wicking powder coating helps pull additional heat off the core surface.
• Built for tow rigs, work trucks, off-road builds, and high-horsepower street trucks.

Installation is designed for minimal modifications into the factory cooler location on 2003-2009 Ram 2500/3500 trucks. Confirm your fitting sizes, then this cooler bolts into your cooling upgrade plan.

RT-48-0309BP Cooler Specs

The RT-48-0309BP checks out on these order-gating specs:

If your engine, transmission, and fitting size match the table above, this is the correct cooler for your build.

Fitment Coverage

Fits 2003-2009 Dodge Ram 2500 and 3500 trucks equipped with the 5.9L or 6.7L Cummins and either the 48RE or 68RFE automatic transmission.

• 2003-2009 Ram 2500/3500 5.9L Cummins - 48RE
• 2007.5-2009 Ram 2500/3500 6.7L Cummins - 68RFE

Confirm your specific engine and transmission pairing before ordering.

Avoid These Common Mistakes

• Ordering without confirming whether your truck runs the 48RE or 68RFE.
• Assuming transmission lines and fittings are included with the cooler.
• Canceling after purchase without contacting us first, which triggers the 20% fee.
• Expecting standard expedited shipping without confirming lead time first.

Final Fit Check

• Truck confirmed 2003-2009 Ram 2500/3500 with 48RE or 68RFE.
• -8AN O-ring line compatibility confirmed.
• Shipping lead time confirmed before ordering to avoid the cancellation fee.

For a 2003-2009 Cummins running the 48RE or 68RFE under heavy load, the RT-48-0309BP is the correct bar and plate cooler upgrade. Confirm your transmission and lead time, then add the RT-48-0309BP to your order.

Frequently Asked Questions