Sierra Lower Unit Seal Kit 18-2652 for Mercruiser Alpha One, Alpha One SS, MR, R Stern Drives (Replaces 26-33144A2)

The Sierra 18-2652 Lower Unit Seal Kit is a gear housing seal set built for Mercruiser stern drive lower units, covering the IA/IB/IC and EZ Shift, MC-I, R, MR, Alpha One, Alpha One SS, and Alpha One Gen II drive families. The kit is machined to precise tolerances so the seals seat correctly in the lower gear housing bore, helping maintain the gear lube seal that keeps water out of the drive and gear oil in. It is used during lower unit rebuilds, gear housing seal replacement, and general stern drive maintenance whenever the lower unit is opened up for service. Sierra manufactures the kit to meet or exceed the original equipment part it replaces, and it is designed to be interchangeable with GLM, Mallory, and Mercruiser OEM seal part numbers, so it drops into the same lower unit application without modification. Because it is a small, precision-machined component, proper installation depth and orientation matter for a leak-free seal, so it should be installed following the stern drive manufacturer's lower unit service procedure. This kit is intended for the specific Mercruiser drive models and year ranges listed below; confirm your drive model and serial number range before ordering to ensure correct fit.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-2652
• Product Type: Lower Unit Seal Kit
• Category: Mercruiser Lower Gear Housing Seal Kit
• Weight: 0.28 pounds
• Product Dimensions: 0.39 x 0.39 x 0.39 inches
• Finish: Machined
• UPC: 030999312631
• Fitment: Mercruiser IA/IB/IC and EZ Shift, MC-I, R, MR, Alpha One, Alpha One SS, Alpha One Gen II stern drives
• OEM Cross Reference: GLM 87510, Mallory 9-74304, Mercruiser 26-89238A1, 26-33144A1, 26-33144A2

Fitment

• 888 / 228 / 250 / 260, 1977-1982
• R, 1983
• MR, Alpha One, 1984-1990
• Alpha One SS, 1986-1989
• Alpha One Gen II, 1991-1995
• Alpha One Gen II, 1996-1997
• Alpha One Gen II (CR), 1996-2010

Replaces (OEM)

• GLM 87510
• Mallory 9-74304
• Mercruiser 26-89238A1
• Mercruiser 26-33144A1
• Mercruiser 26-33144A2

Frequently Asked Questions

What does the Sierra 18-2652 Lower Unit Seal Kit fit? The 18-2652 kit fits Mercruiser IA/IB/IC and EZ Shift, MC-I, R, MR, Alpha One, Alpha One SS, and Alpha One Gen II stern drive lower units, covering model years from 1977 through 2010 depending on the specific drive and serial number range.

Is the 18-2652 kit compatible with Alpha One Gen II drives? Yes, Sierra 18-2652 is listed for Alpha One Gen II drives built for the 1991-1995 and 1996-1997 model years, as well as the Alpha One Gen II (CR) configuration covering 1996-2010.

What OEM part numbers does the 18-2652 seal kit replace? It is designed to be interchangeable with GLM 87510, Mallory 9-74304, and Mercruiser 26-89238A1, 26-33144A1, and 26-33144A2.

Does 18-2652 cross-reference to a Mercury Marine part number? Yes, the Sierra 18-2652 Lower Unit Seal Kit cross-references to Mercury Marine 26-33144A2.

How much does the Sierra 18-2652 seal kit weigh? The kit weighs 0.28 pounds.

What are the dimensions of the 18-2652 seal kit? The Sierra 18-2652 kit measures 0.39 x 0.39 x 0.39 inches.

Will 18-2652 fit a 1983 MC-I drive? Yes, the R model 1983 application (serial numbers 6225577 and up) is covered by the Sierra 18-2652 lower unit seal kit.

Is the Sierra 18-2652 a genuine Sierra part or an aftermarket copy? It is a genuine Sierra-manufactured part, made to meet or exceed the specifications of the original equipment seal it replaces, and it carries Sierra's standard customer satisfaction warranty.

What finish does the 18-2652 seal kit have? The Sierra 18-2652 Lower Unit Seal Kit has a machined exterior finish.

When would I need to install the 18-2652 seal kit? This kit is used when servicing the lower gear housing on a compatible Mercruiser stern drive, such as during a lower unit rebuild or when gear lube seals need replacing to stop water intrusion or oil leaks.

Does the 18-2652 kit fit the Alpha One SS drive? Yes, Sierra 18-2652 is listed for the Alpha One SS drive covering the 1986-1989 model years, serial numbers A545004 and up.

What is the UPC for the Sierra 18-2652 Lower Unit Seal Kit? The UPC for this product is 030999312631.