Sierra Upper Unit Seal Kit 18-2644 - Replaces 26-88397A1 - Mercruiser Alpha I Generation II Stern Drive

The Sierra 18-2644 Upper Unit Seal Kit supplies the seals and gaskets needed to properly rebuild the upper gear housing on a Mercruiser Alpha I Generation II stern drive. This kit replaces OEM number 26-88397A1 and is engineered to meet or exceed the specifications of the original equipment part it replaces. Sierra supplies many OEM engine manufacturers and boat builders with quality marine parts, and this seal kit is built to stand up to the harsh marine environment while sealing the upper unit against water intrusion and lubricant loss.

The kit contains a Seal Gasket (Sierra 18-2944, OE 26-45577-1) and a Drain Screw Gasket (Sierra 18-2945, OE 12-19183-3), each supplied in a quantity of 1, giving the installer the correct sealing components for an upper unit service or rebuild in one package. Using a complete seal kit at rebuild time helps prevent water intrusion into the gear housing and lubricant leaks that can lead to premature gear and bearing wear.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-2644
• Product Name: Upper Unit Seal Kit
• Weight: 0.14 pounds
• Color: White
• Shape: Round
• UPC: 030999875211
• Kit Contents: Seal Gasket (18-2944, OE 26-45577-1), qty 1; Drain Screw Gasket (18-2945, OE 12-19183-3), qty 1

Fitment

• Mercruiser Alpha I Generation II stern drive

Replaces (OEM)

• 26-88397A1

Frequently Asked Questions

What does the Sierra 18-2644 Upper Unit Seal Kit fit? The 18-2644 kit is designed for the Mercruiser Alpha I Generation II stern drive upper gear housing.

What OEM part number does 18-2644 replace? Sierra 18-2644 replaces OEM number 26-88397A1.

What is included in the 18-2644 seal kit? The kit includes a Seal Gasket (Sierra 18-2944, OE 26-45577-1) and a Drain Screw Gasket (Sierra 18-2945, OE 12-19183-3), one of each.

How much does the 18-2644 seal kit weigh? The Sierra 18-2644 Upper Unit Seal Kit weighs 0.14 pounds.

Is the Sierra 18-2644 kit genuine OEM or aftermarket? It is a Sierra aftermarket replacement kit engineered to meet or exceed the specifications of the original 26-88397A1 equipment it replaces, not a Mercruiser branded OEM part.

When should I replace the upper unit seal kit on my stern drive? The 18-2644 kit is intended for use during a rebuild or service of the Alpha I Generation II upper gear housing, whenever the existing seals and gaskets are removed or show signs of wear or leakage.

What color is the Sierra 18-2644 kit's gasket material? The gasket material included in the 18-2644 kit is white.

Does the 18-2644 kit include a drain screw gasket? Yes, the kit includes Sierra 18-2945, a drain screw gasket with OE reference 12-19183-3, in a quantity of one.

What shape is the seal gasket in the 18-2644 kit? The seal gasket included in the Sierra 18-2644 kit is round in shape.

Can I use the 18-2644 kit on a different stern drive model? The 18-2644 kit is specified for the Mercruiser Alpha I Generation II upper unit; fitment to other stern drive models is not listed for this part.