Pacific Performance Engineering (PPE) 10L1000 Bar and Plate Transmission Cooler
Fits 2020-2026 6.6L Duramax V8 (L5P) · 6.6L Duramax V8 (L5P, updated)
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Price tracked 10 times since Jul 26, 2026 across the stores we check daily: low $350.99, high $389.99, currently $350.99.
A transmission cooler is a small radiator that keeps the Allison's fluid from overheating when you tow. This one replaces the factory cooler with a much thicker bar-and-plate core and bolts to the stock mounting points.
why this one — PPE publishes hard numbers for this one instead of adjectives: a 395 cubic inch core, 3.28 times the stock volume, 80 percent more frontal area, and up to 45F lower fluid temperature. The downside is bulk. It is a thick core sitting in front of the radiator and condenser, so it packs with bugs and road grit faster than stock and needs blowing out.
Cooling part, no power claim applies. PPE publishes a 395 cubic-inch core (3.28x stock volume), 80% larger frontal area, and up to 45F lower transmission fluid temperature. source ↗
No published gain figure for this part, and nothing here is a guarantee. Price is a list price and can lag the retailer; confirm at checkout. See how we check a price and our affiliate disclosure.