Shop By Category
Your Cart

01-05 6.6L GM Duramax XDP X-TRA Cool Direct-Fit Transmission Cooler

The XDP X-TRA Cool Direct-Fit Transmission Oil Cooler XD309 is a direct upgrade for the factory transmission oil cooler in your 2001-2005 GM 6.6L Duramax LB7/LLY.  XDP’s XTRA-Cool Transmission Oil Coolers are made using techniques borrowed from the HD and semi-truck industry to provide you with the ultimate in strength and durability. Built for more than just increased strength, the XD309 features a high-efficiency core that is specially designed to maximize transmission cooling potential over the factory unit. Each kit comes ready to install with the needed fittings, brackets, and hardware to make this a bolt-on installation for your GM Duramax/Allison powetrain. 




Replaces Factory Cooler

Upgraded Design For Increased Durability

High-Efficiency Core To Maximize Cooling 

XD309 Specifications:

Core Width: 12-1/2" 

Core Height: 7-3/4" 

Core Thickness: 2" 

Overall Length: 16" 

Cooler Fittings: 7/8-14 UNF  


Application Notes:

This transmission cooler is intended for use with the factory transmission lines. 

XDP cannot guarantee fitment with aftermarket transmission lines. 



Products manufactured by XDP carry a 1-Year warranty against defects in materials and craftsmanship. The Warranty is Limited to one (1) year from the date of sale and limited solely to the parts contained within the product's kit. 

Part number: XD309


Lame California Prop 65 Notice