The Mishimoto transmission cooler for the 2017-2019 Chevrolet/GMC 6.6L Duramax L5P is a direct-fit, stacked-plate upgrade that lowers fluid temperatures for towing, fleet, and daily-driven trucks running the Allison 1000 transmission. Its 13-row core delivers 67% greater core volume and 164% greater fin surface area than the stock cooler, and CNC-machined adapters connect to the factory lines (or AN lines) for leak-free flow with direct-fit brackets, tailor-made hoses, and an air-temp sensor relocation bracket. Note: Silverado models require minor grille trimming; GMC Sierra does not.
| Type | Direct-fit transmission cooler |
| Core | 13-row stacked-plate |
| Transmission | Allison 1000 |
| vs. Stock | +67% core volume, +164% fin area |
| Fittings | CNC-machined adapters (stock line or AN) |
| Note | Silverado requires minor grille trimming |
| Part Number | MMTC-DMAX-17SL |
| Warranty | Mishimoto Lifetime Warranty |
This part fits:
| Year | Make | Model | Submodel |
|---|---|---|---|
| 2017-2019 | Chevrolet | Silverado 2500 HD | High Country |
| 2017-2019 | Chevrolet | Silverado 2500 HD | LT |
| 2017-2019 | Chevrolet | Silverado 2500 HD | LTZ |
| 2017-2019 | Chevrolet | Silverado 2500 HD | WT |
| 2017-2019 | Chevrolet | Silverado 3500 HD | High Country |
| 2017-2019 | Chevrolet | Silverado 3500 HD | LT |
| 2017-2019 | Chevrolet | Silverado 3500 HD | LTZ |
| 2017-2019 | Chevrolet | Silverado 3500 HD | WT |
| 2017-2019 | GMC | Sierra 2500 HD | Base |
| 2017-2019 | GMC | Sierra 2500 HD | Denali |
| 2017-2019 | GMC | Sierra 2500 HD | SLE |
| 2017-2019 | GMC | Sierra 2500 HD | SLT |
| 2017-2019 | GMC | Sierra 3500 HD | Base |
| 2017-2019 | GMC | Sierra 3500 HD | Denali |
| 2017-2019 | GMC | Sierra 3500 HD | SLE |
| 2017-2019 | GMC | Sierra 3500 HD | SLT |
Shipping: In-stock orders placed before 3 PM EST ship the same day, and everything else ships within 24 hours. Standard, expedited, and overnight options are available at checkout. Backordered items ship as soon as we get them back in stock. Contact us for lead times. See the full Shipping Policy.
Returns: 30-day returns on new, unused items in original packaging. See the full Refund Policy.
