Sierra Lower Unit Seal Kit 18-2645-1, Replaces 26-76868A1, Fits Mercruiser Bravo I, II and III

The Sierra Lower Unit Seal Kit, part number 18-2645-1, is a complete gasket and seal set for rebuilding the lower gear housing on Mercruiser Bravo I, II, and III stern drive units. Instead of sourcing individual gaskets and seals separately, this kit bundles the three components needed for a proper lower unit reseal into one part number, helping ensure nothing is missed during a rebuild or seal replacement job.

The kit contains a gear housing drain screw gasket (OE 12-19183, quantity 2), a water pocket cover gasket (OE 27-55810, quantity 1), and an oil seal (OE 26-823894). These components are cross-referenced to fit in place of the original Mercruiser parts and are commonly needed together whenever the lower unit is opened up for service, such as during a water pump replacement, gear lube change with inspection, or general lower unit maintenance.

This kit is designed specifically for Bravo I, II, and III model stern drives and carries OEM cross-reference numbers 26-76868A1, 26-76868A2, and 26-76868A04, so it can be matched against those Mercruiser part numbers when confirming fitment. The kit weighs 0.42 pounds as packaged.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-2645-1
• Product Type: Lower Unit Seal Kit
• Fitment: Mercruiser Bravo I, II & III Models
• OEM Cross-Reference: 26-76868A1, 26-76868A2, 26-76868A04
• Kit Contents: Gear Housing Drain Screw Gasket (OE 12-19183, Qty 2), Water Pocket Cover Gasket (OE 27-55810, Qty 1), Oil Seal (OE 26-823894)
• Weight: 0.42 pounds
• Package Dimensions: 1.5 x 6 x 6 inches
• UPC: 808282383237

Fitment

• Mercruiser Bravo I, II & III Models

Replaces (OEM)

• 26-76868A1
• 26-76868A2
• 26-76868A04

Frequently Asked Questions

What does the Sierra 18-2645-1 lower unit seal kit fit? This kit is designed for Mercruiser Bravo I, II, and III model stern drives and is used when servicing the lower gear housing on those units.

What OEM part numbers does 18-2645-1 replace? The kit cross-references to Mercruiser OEM numbers 26-76868A1, 26-76868A2, and 26-76868A04, so it can be used in place of any of those part numbers.

What is included in the 18-2645-1 kit? Three components are included: a gear housing drain screw gasket (OE 12-19183, quantity 2), a water pocket cover gasket (OE 27-55810, quantity 1), and an oil seal (OE 26-823894).

How many drain screw gaskets come in the kit? Two gear housing drain screw gaskets (OE 12-19183) are included in the 18-2645-1 kit, along with one water pocket cover gasket and one oil seal.

How much does the Sierra 18-2645-1 seal kit weigh? The kit weighs 0.42 pounds as packaged.

What are the package dimensions of this kit? The Sierra 18-2645-1 lower unit seal kit measures 1.5 x 6 x 6 inches as packaged.

Is this an aftermarket or genuine Mercruiser part? 18-2645-1 is a Sierra-brand replacement kit manufactured to match the fit of the original Mercruiser components it cross-references, rather than a Mercruiser-branded part.

When would I need to replace the seals in this kit? These gaskets and the oil seal are typically replaced whenever the lower gear housing on a Bravo I, II, or III drive is opened for service, such as during a rebuild or water pump job, to ensure a proper seal is maintained.

Does this kit work on Bravo I, II, and III drives interchangeably? Yes, the Sierra 18-2645-1 kit is listed for Bravo I, II, and III model stern drives.

What is the UPC for the Sierra 18-2645-1 kit? The UPC for this Lower Unit Seal Kit is 808282383237.