Mishimoto Dodge Ram 2003-2007 5.9L Cummins Replacement Transmission Oil Cooler

The factory liquid-to-liquid transmission oil cooler on the 2003-2007 Dodge Ram 5.9L Cummins uses engine coolant to regulate transmission fluid temperature. When the unit wears out it can leak coolant into the transmission fluid — a mix that can destroy a transmission. This Mishimoto replacement is a direct-fit, OEM-equivalent oil cooler that installs with no modification, letting you replace the factory cooler preventatively before it fails. Made to OEM specifications in corrosion-resistant aluminum, it includes a new powder-coated bracket and brass fittings.

Specifications

Documents: Installation Instructions (PDF)

This part fits:

Shipping

• In-stock orders placed before 3 PM EST ship the same day — everything else ships within 24 hours.
• Standard, expedited, and overnight options at checkout.
• Oversized items ship by freight and take longer.
• Backordered items ship as soon as stock lands — contact us for lead times.
• International orders: prices do not include VAT, duties, or import fees. Your country charges these at import and they are the buyer’s responsibility.

Returns

• 30-day returns on new, uninstalled items in original packaging with all hardware.
• Standard returns: 8% restocking fee, buyer pays return shipping. Both waived if the item is defective or we made the error.
• Installed or used parts can’t be returned — confirm fitment before you install.
• Special orders and custom items are final sale.
• Email us for return authorization before shipping anything back.

Full details: Shipping Policy · Refund Policy