Sierra 18-2244 Marine Gear Lube Drain Plug, 3/8-16 Thread, Fits MerCruiser I/R/MR/Alpha One/TR/TRS and Outboards

The Sierra 18-2244 is a marine gear lube drain plug sized for 3/8-16 fill and vent screw ports. It is used to seal the gear lube fill or vent opening on lower units and gearcases, allowing technicians and boat owners to service gear lube without leaving the port open to water intrusion or debris. The plug is available in brass or stainless steel construction, both materials chosen for their resistance to corrosion in saltwater and freshwater marine environments.

This drain plug is sized to fit MerCruiser I, R, MR, Alpha One, TR, and TRS sterndrive units, as well as all outboards that use a 3/8-16 non-magnetic gear lube fill or vent screw. It ships as a single plug (package quantity of 1), making it a straightforward replacement when an existing fill or vent screw is stripped, corroded, or missing. At 0.03 pounds, it is a small, lightweight hardware component intended to be kept on hand as spare gearcase service hardware.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-2244
• Product Type: Drain Plug
• Thread Size: 3/8-16 inch (9.5mm)
• Material: Brass, Stainless Steel
• Color: Multi-coloured
• Package Quantity: 1
• Weight: 0.03 pounds
• UPC: 747730043487

Fitment

• MerCruiser I, R, MR, Alpha One, TR, TRS
• All outboards with 3/8-16 non-magnetic gear lube fill or vent screws

Frequently Asked Questions

What is the thread size of the Sierra 18-2244 drain plug? It uses a 3/8-16 inch (9.5mm) thread, matching standard gear lube fill and vent screw ports on covered MerCruiser and outboard lower units.

Will the 18-2244 fit my MerCruiser sterndrive? Sierra 18-2244 fits MerCruiser I, R, MR, Alpha One, TR, and TRS drive units.

Does this plug work on outboard motors? Yes, the 18-2244 fits all outboards that use a 3/8-16 non-magnetic gear lube fill or vent screw.

What is this part made of? The Sierra 18-2244 drain plug is constructed from brass or stainless steel, both corrosion-resistant materials suited to marine gearcase service.

How many plugs come in a package? The 18-2244 is sold with a package quantity of 1 item.

How much does the 18-2244 weigh? It weighs 0.03 pounds, a small, lightweight gearcase hardware component.

Is the 18-2244 magnetic? No, it is designed as a non-magnetic gear lube fill or vent screw, per its stated fitment for non-magnetic ports.

What is this plug used for? The Sierra 18-2244 seals a gear lube fill or vent opening on a lower unit or gearcase during gear lube service.

Is the Sierra 18-2244 an OEM or aftermarket part? The 18-2244 is a Sierra-branded replacement plug sized to fit the OEM 3/8-16 gear lube fill and vent ports listed for MerCruiser and outboard applications.

Can I use this plug on both the fill and vent ports? Yes, the 18-2244 is sized for 3/8-16 non-magnetic gear lube fill or vent screw locations.