Heating and Cooling› Oil and Fluid Coolers

XDP Xtreme Diesel Performance

X-TRA Cool Direct-Fit Transmission Oil Cooler

$235.95

SKU: XD309

Out of Stock
Free Shipping over $200
$100 Minimum Order
Non-Returnable Item
INSTALL DIFFICULTY
DIY PRO SHOP

Moderate — 2–4 hours

Overview

The XDP X-TRA Cool Direct-Fit Transmission Oil Cooler XD309 is an upgraded replacement for the factory transmission oil cooler in 2001-2005 GM 6.6L Duramax LB7/LLY engines. It is built using techniques from the HD and semi-truck industry for enhanced strength and durability.
Show original supplier description
The XDP X-TRA Cool Direct-Fit Transmission Oil Cooler XD309 serves as a direct upgrade for the factory transmission oil cooler in 2001-2005 GM 6.6L Duramax LB7/LLY vehicles. Constructed with techniques borrowed from the heavy-duty and semi-truck industry, this cooler offers superior strength and durability. Featuring a high-efficiency core, the XD309 is engineered to maximize transmission cooling potential beyond the capabilities of the stock unit. Its design aims to provide reliable and consistent cooling, even under demanding conditions. The cooler is designed as a direct-fit replacement, ensuring a bolt-on installation for your GM Duramax/Allison powertrain. Included in the kit are all necessary fittings, brackets, and hardware for a straightforward installation. The cooler specifications include a core width of 12-1/2 inches, a core height of 7-3/4 inches, and a core thickness of 2 inches, with an overall length of 16 inches. The cooler fittings are 7/8-14 UNF. This transmission cooler is intended for use with factory transmission lines. XDP cannot guarantee fitment with aftermarket transmission lines. All XDP products come with a 1-Year warranty against defects in materials and craftsmanship.

Product descriptions are provided by our supplier partners and may not always be perfectly accurate. Not sure this fits? or call (760) 282-4645 and we’ll verify before you order.

Fitment

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Specifications

BrandXDP Xtreme Diesel Performance
Part NumberXD309
CategoryHeating and Cooling
5,000+ Trusted brands
1M+ Enthusiasts
5M+ Parts sold
(760) 282-4645 hello@motormia.co

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Returns & Fitment

Built for enthusiasts. Every order is backed by our 30 day return window on eligible items. Unused and uninstalled products may be returned with approved RMA and no restocking fees when received in new condition. Orders placed through the MOTORMIA app with a complete build qualify for our Fitment Guarantee — free return shipping if the part doesn’t fit your exact setup. The guarantee covers fit only; installation must follow manufacturer instructions, and we recommend a qualified shop for parts marked Difficulty 4–5.

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Shipping

Orders are processed in 1–3 business days. In stock parts ship promptly from our partner network. Special-order items either aren’t currently stocked or are built to your spec — expect 4–6 weeks. If a part goes on backorder while your order is in the queue, we’ll reach out and work through discounted alternatives together.

Free shipping over $200 in the continental US. Alaska, Hawaii, U.S. territories (Puerto Rico, U.S. Virgin Islands, Guam, American Samoa, and the Northern Mariana Islands), and international orders carry surcharges — most appear at checkout. Some exceptions (LTL freight, or suppliers who quote freight only after we place the order) won’t. In those cases we’ll reach out with the exact charge before your order moves forward.

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