Sierra 18-3116 Water Pump Housing for MerCruiser Alpha One Sterndrives, Replaces 46-96148A1

The Sierra 18-3116 Water Pump Housing is a direct-fit replacement housing for MerCruiser sterndrive and inboard cooling systems, designed to restore proper raw water circulation through the water pump assembly. Molded from durable plastic, this housing forms the outer body of the water pump and works together with the impeller, face plate, and related pump components to draw and route cooling water to the engine. It is engineered to meet or exceed the specifications of the original equipment part it replaces, giving boat owners a reliable option for water pump rebuilds and maintenance.

This housing is used across multiple MerCruiser sterndrive generations identified by unit serial number range, including units without a flush screw in the gear housing and MR/Alpha I configurations. Because water pump housings differ by drive generation and gearcase design, buyers should confirm their unit's serial number range or drive designation before ordering to ensure correct fitment. The 18-3116 pairs with related Sierra water pump components such as the 18-3109 water tube guide and 18-3110 water pump housing bushing, and is commonly installed as part of a full water pump kit during routine impeller service or cooling system overhaul.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-3116
• Product Type: Water Pump Housing
• Material: Plastic
• Weight: 0.46 pounds
• Category: Mercury Outboard Water Pumps and Impellers
• UPC: 030999315519
• OEM Cross-Reference: GLM 12410, Mallory 9-43211, Mercury/Mercruiser 46-96148A1, 46-96148T1, 46-64141A1, 46-48743A1

Fitment

• MerCruiser units, serial number range 2495186-2763441
• MerCruiser units without flush screw in gear housing, serial number range 2763442-6854392
• MerCruiser MR/Alpha I, serial number range 6854393-0D594568

Replaces (OEM)

• GLM 12410
• Mallory 9-43211
• Mercury/Mercruiser 46-96148A1
• 46-96148T1
• 46-64141A1
• 46-48743A1

Frequently Asked Questions

What is the Sierra 18-3116 used for? The Sierra 18-3116 is a water pump housing that forms the outer body of the water pump on applicable MerCruiser sterndrive units, routing raw cooling water through the pump assembly to the engine.

Is the 18-3116 a direct replacement for the Mercury/MerCruiser 46-96148A1? Yes, the Sierra 18-3116 water pump housing is interchangeable with Mercury/MerCruiser 46-96148A1, along with 46-96148T1, 46-64141A1, and 46-48743A1.

What material is the 18-3116 housing made from? This water pump housing is made from plastic, matching the material used in the original equipment component it replaces.

How much does the 18-3116 water pump housing weigh? The Sierra 18-3116 weighs 0.46 pounds.

Will the 18-3116 fit any MerCruiser sterndrive? No, fitment depends on unit serial number range and drive configuration; the 18-3116 applies to serial ranges 2495186-2763441, 2763442-6854392 (units without a flush screw in the gear housing), and 6854393-0D594568 (MR/Alpha I units), so confirming your unit's serial number is recommended before ordering.

What other parts does the 18-3116 work with? The 18-3116 housing is designed to pair with the Sierra 18-3109 water tube guide and 18-3110 water pump housing bushing, and is included in Sierra water pump kits such as the 18-3314, 18-3316, 18-3317, 18-3319, 18-3320, and 18-3321.

Does the 18-3116 come with the impeller included? No, the Sierra 18-3116 is the housing component only; the impeller and other wear parts are sold separately or as part of a complete water pump kit.

Are GLM 12410 and Mallory 9-43211 the same part as the Sierra 18-3116? GLM 12410 and Mallory 9-43211 are interchangeable cross-reference numbers for the same water pump housing as the Sierra 18-3116.

Is the Sierra 18-3116 genuine OEM or aftermarket? The 18-3116 is a Sierra aftermarket replacement part manufactured to meet or exceed the specifications of the original MerCruiser equipment it replaces.

Can the 18-3116 be used on units with a flush screw in the gear housing? The 18-3116 is listed for units without a flush screw in the gear housing as well as certain earlier and MR/Alpha I serial ranges; units retro-fitted with an Alpha-style lower unit require Alpha-style parts instead.