DEEFILL Oil Filter Adapter 13/16"-16 to 1 1/8"-16, SUS304 Stainless CNC-Machined for Heavy-Duty Seal

The DEEFILL oil filter adapter converts a 13/16"-16 engine filter port to accept larger 1 1/8"-16 threaded filters like the CAT 1R-1807, in durable SUS304 stainless steel for long-term, leak-resistant service.

This precision CNC-machined adapter lets you use larger, higher-capacity oil filters without altering the engine. Made from solid SUS304 stainless bar stock, threads are cut to exact tolerances to ensure a clean seat and reliable seal under high oil pressures and elevated temperatures common in diesel and heavy-duty equipment. Install with basic hand tools in minutes and expand your filter choices to widely available 1 1/8"-16 models.

How does this adapter let me upgrade to a CAT 1R-1807 style filter?

The adapter replaces the smaller factory female thread with a robust external 1 1/8"-16 threaded surface so you can screw on larger aftermarket or OEM filters. There’s no machining of the engine required — simply thread the adapter onto the existing 13/16"-16 port and tighten to spec.

• Converts 13/16"-16 engine port to 1 1/8"-16 filter thread
• Fits CAT 1R-1807 and many equivalent filters (Baldwin, NAPA, WIX, FRAM, etc.)
• Install by hand then snug with a wrench — no permanent engine modifications

Will this hold up to diesel engine oil pressure and heat?

Yes — the adapter is CNC-machined from SUS304 stainless steel to resist corrosion, galling, and deformation under high temperatures and sustained oil pressure. Unlike cheap cast adapters, solid bar-stock machining eliminates internal voids and soft spots that lead to premature failure.

• SUS304 stainless resists rust and oil-related corrosion
• Precision threads provide reliable, leak-free engagement
• Designed for heavy-duty and diesel applications (Duramax, CAT, Volvo, AGCO)

Which engines and filters is this compatible with?

The adapter is built for any engine with a 13/16"-16 female filter port that you want to convert to accept a 1 1/8"-16 filter. It's known to suit Duramax installations and is compatible with widely-used replacement filters such as CAT 1R-1807, VOLVO 478736, AGCO AG121853, BALDWIN B7225, and NAPA 7791.

• Check your current port thread: must be 13/16"-16 before ordering
• Accepts any 1 1/8"-16 threaded oil filter
• Common compatible part numbers listed on the product page

How simple is installation and what tools are required?

Installation is straightforward and designed for DIY mechanics: thread the adapter onto the engine port by hand and finish tightening with a standard wrench. No specialty tools, welding, or engine disassembly are necessary — most jobs complete in minutes.

• Hand-thread onto 13/16"-16 port, then snug with a wrench
• No engine modification or machining needed
• One-piece adapter included in the package

Who is this for: The DEEFILL adapter is for owners and technicians who want to upgrade filtration capacity on diesel, commercial, agricultural, or heavy-equipment engines that use a 13/16"-16 filter port. If you need to fit larger 1 1/8"-16 filters such as CAT 1R-1807 or equivalent models — for increased media volume and longer service intervals — but don’t want permanent changes to the engine, this stainless-steel, CNC-machined adapter provides a durable, easy-to-install solution. Always verify your engine’s port thread size is 13/16"-16 before purchase.