Sierra Oil Seal 18-2047 - Replaces Volvo 958860-9

The Sierra 18-2047 Oil Seal is a precision-machined replacement seal designed for marine drive and lower unit applications where a reliable oil barrier is required. It is built to prevent lubricant leakage and keep contaminants such as water out of gear housings, helping protect internal components from premature wear and corrosion. This seal is manufactured with a machined exterior finish for a consistent, accurate fit against the housing bore, and it is engineered to directly replace the Volvo 958860-9 seal, making it a straightforward swap for boat owners and marine technicians performing routine maintenance or seal replacement during a rebuild.

At just 0.06 pounds, this is a compact, lightweight component sized for tight tolerances typical of drive and gearcase seals. Sierra sources and manufactures its parts to consistent quality standards, and this seal carries a Taiwan country of origin. Whether you are servicing a lower unit, replacing a worn seal that has started to leak, or completing a full gearcase rebuild, the 18-2047 is sized and finished to restore a proper seal without modification.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-2047
• OEM Cross Reference: Volvo 958860-9
• Product Dimensions: 0.39 x 0.39 x 0.39 inches
• Weight: 0.06 pounds
• Exterior Finish: Machined
• Country of Origin: Taiwan

Fitment

Direct cross-reference replacement for Volvo 958860-9.

Replaces (OEM)

• VOLVO 958860-9

Frequently Asked Questions

What does the Sierra 18-2047 oil seal fit? The Sierra 18-2047 is a direct cross-reference replacement for Volvo 958860-9, so it fits wherever that Volvo seal is specified.

Is the Sierra 18-2047 the same as Volvo part 958860-9? Yes, Sierra 18-2047 is manufactured as a direct equivalent to Volvo 958860-9 and can be used as a replacement for it.

How much does the 18-2047 oil seal weigh? This oil seal weighs 0.06 pounds, making it a small, lightweight component typical of gearcase and drive seals.

What are the dimensions of the Sierra 18-2047 seal? The seal measures 0.39 x 0.39 x 0.39 inches, a compact size sized to seat directly in the original housing bore.

What is the exterior finish on this seal? The Sierra 18-2047 has a machined exterior finish, which provides a precise, consistent fit against the mounting bore.

Where is the Sierra 18-2047 oil seal manufactured? The country of origin for the 18-2047 oil seal is Taiwan.

Is this a genuine Sierra part or an aftermarket copy? The 18-2047 is a Sierra-branded part manufactured as a cross-reference replacement for the OEM Volvo 958860-9 seal, not a copy sold under the original OEM label.

What is included when I order the 18-2047? Ordering the Sierra 18-2047 includes one oil seal; no additional hardware or gaskets are included.

Can this seal be used during a lower unit rebuild? Yes, the Sierra 18-2047 is suited for use when rebuilding a gearcase or lower unit that originally used the Volvo 958860-9 seal.

Why would I need to replace this oil seal? An oil seal like the 18-2047 is typically replaced when it begins leaking gear lubricant or allowing water intrusion into the housing, both signs of a worn or failed seal.