Sierra 18-3217 Impeller Kit for Mercury MerCruiser #1 Series and MR/Alpha One Sterndrives

The Sierra 18-3217 Impeller Kit is a complete water pump rebuild kit for Mercury MerCruiser sterndrives, covering standard housing units, #1 series units without a flush screw in the gear housing, and MR/Alpha One lower units within the serial number ranges listed below. The kit is built around a neoprene rubber impeller, chosen for its flexibility and long-lasting performance under the heat and wear conditions of a marine cooling system. Every impeller is molded to Sierra's quality standards and inspected and tested for proper bonding before it ships.

Beyond the impeller, the kit bundles every gasket, seal, and O-ring needed to fully reseal the water pump and gear housing in one job, so an installer is not left short a part mid-repair. Components include a water tube, mounting plate, seal ring, grommet, and a full set of pump and gear housing gaskets and O-rings. The kit is made to meet or exceed original equipment specifications for fit and performance, and ships in non-retail packaging.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-3217
• Product Type: Impeller Kit
• Material: Rubber
• Item Dimensions: 4 x 3 x 1 inches
• Weight: 0.37 pounds
• Number of Items: 1
• UPC: 030999236890
• Kit Contents: Water Tube (18-3109), Impeller (18-3017), Water Pump Base to Gear Housing Gasket (18-2919), Grommet (18-3110), Gear Housing Drain Screw Gaskets (18-2945, qty 2), Water Pump Base to Gear Housing Gasket (18-2826), Lower Water Pump to Wear Plate Gasket (18-2914), Upper Water Pump to Wear Plate Gasket (18-2915), Seal Ring (18-2944), Plate (18-3117), O-Rings (18-7158, 18-7162, 18-7173, 18-7176, 18-7196, 18-7426), Water Pump Gasket (18-2801)
• Packaging: Non-retail packaging

Fitment

• Mercury MerCruiser standard water pump housing, serial numbers 2495186 through 2763441
• Mercury MerCruiser #1 units without a flush screw in the gear housing, serial numbers 2763442 through 6854392
• Mercury MerCruiser MR/Alpha One lower units, serial numbers 6854393 through 0D594568

Frequently Asked Questions

What does the Sierra 18-3217 impeller kit include? The kit includes one water tube, one impeller, seven gaskets, one grommet, one seal ring, one plate, and six O-rings, giving an installer everything needed to reseal the water pump and gear housing in a single job.

What serial number range does part 18-3217 fit? 18-3217 is designed for Mercury MerCruiser standard housing units in the serial range 2495186 through 2763441, #1 units without a flush screw in the gear housing from 2763442 through 6854392, and MR/Alpha One lower units from 6854393 through 0D594568.

What material is the impeller made from? The impeller in kit 18-3217 is made from a neoprene rubber compound, chosen for added flexibility and long-lasting performance in the cooling system.

Does the 18-3217 kit come in retail packaging? No, the Sierra 18-3217 impeller kit ships in non-retail packaging.

How much does the 18-3217 impeller kit weigh? The Sierra 18-3217 impeller kit weighs 0.37 pounds.

What are the dimensions of the impeller kit? The 18-3217 kit measures 4 x 3 x 1 inches as packaged.

Is the Sierra 18-3217 impeller kit made to OEM specifications? Yes, the 18-3217 kit is made to meet or exceed original equipment specifications for fit and performance.

How many O-rings are in the 18-3217 kit and what are their part numbers? The kit contains six O-rings, Sierra part numbers 18-7158, 18-7162, 18-7173, 18-7176, 18-7196, and 18-7426.

What is the water tube part number included with 18-3217? The water tube included in the 18-3217 kit is Sierra part number 18-3109.

Will 18-3217 fit a unit with a flush screw in the gear housing? 18-3217 is specified for units without a flush screw in the gear housing within the listed serial ranges; units retro-fitted with an Alpha style lower unit that lacks a pre-load pin in the top of the driveshaft require Alpha style parts instead.

Is Sierra 18-3217 covered by a warranty? Yes, the 18-3217 impeller kit is covered under Sierra's customer satisfaction warranty.

How many gaskets come with the 18-3217 impeller kit? The kit includes seven gaskets total: two water pump base to gear housing gaskets (18-2919 and 18-2826), two gear housing drain screw gaskets (18-2945), a lower wear plate gasket (18-2914), an upper wear plate gasket (18-2915), and a water pump gasket (18-2801).