Upgrade Your Duramax: Forged Diesel Billet Engine Oil Cooler Adapter (LB7 / LLY / LBZ / LML / L5P)
A small, high-impact upgrade for 2001–2007 and 2011–2019 6.6L GM Duramax engines — replace the stock leaking adapter with a Billet Duramax Oil Cooler Adapter, O-ring sealed unit for reliable performance and peace of mind.
Why this upgrade matters
The factory oil cooler adapter uses a metal gasket that is prone to leaking over time. The Forged Diesel billet adapter replaces that weak link with a precision machined billet aluminum part that uses an O-ring style gasket for a long-lasting, leak-proof installation — a straightforward reliability upgrade for LB7, LLY, LBZ, LML, L5P 6.6L Duramax engines.
Quick product snapshot
| Part | Forged Diesel Billet Engine Oil Cooler Adapter |
|---|---|
| Fitment | 2001–2007 & 2011–2019 GM 6.6L Duramax — LB7, LLY, LBZ, LML, L5P |
| Material | Billet aluminum |
| Seal type | O-ring (improved over factory metal gasket) |
| Price | $104.95 |
| SKU | 245001 |
Key benefits
- Leak reduction: O-ring sealing reduces the chances of oil/coolant cross-contamination and messy leaks.
- Durability: Billet construction is stronger and more precise than stamped or cast factory pieces.
- Direct fit: Designed for Duramax fitment — no fabrication required.
- Low cost, high value: Small investment that prevents larger failures or downtime later.
Watch the install & product video
FAQ
- Will this fit my truck?
- Fits 2001–2007 and 2011–2019 GM 6.6L Duramax LB7, LLY, LBZ, LML, L5P
- Does it come with the O-ring?
- Yes. Built in oil ring.
- Can I reuse the factory bolts?
- In most cases factory bolts can be reused if they are in good condition — use factory torque specs. Replace any damaged bolts. If you’re unsure, replace hardware during install.
- Will this reduce oil temperature?
- Not directly — this part improves sealing and reliability of the oil cooler adapter. Proper oil cooling depends on the entire cooler system and oil flow; this adapter prevents oil loss and coolant contamination that could otherwise compromise cooling performance.
Ready to upgrade?
Keep your Duramax sealed and worry-free — pick up the Forged Diesel Billet Engine Oil Cooler Adapter and avoid the common metal-gasket failure.
Forged Diesel Billet Engine Oil Cooler Adapter, 2001-2007, 2011-2019 GM 6.6L Duramax LB7 LLY LBZ LML L5P
$104.95
Forged Diesel Billet Engine Oil Cooler Adapter For 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019 GM 6.6L Duramax LB7 LLY LBZ LML L5P Forged Diesel parts are made with the highest… read more
Final Thoughts
The Forged Diesel Billet Engine Oil Cooler Adapter is one of those upgrades that doesn’t grab headlines like turbo builds or monster injectors, but it does provide reliability and peace-of-mind for your Duramax platform.
Don’t wait for a gasket leak to cause oil loss or coolant contamination — upgrade now, get it out of the way, and get back to enjoying the drive (or the work) with confidence.