Sierra 18-79814 Shim Gauge Bar, Replaces 349957, for 40 HP V-8 Outboards with Thru Hub Exhaust

The Sierra 18-79814 Shim Gauge Bar is a precision service tool used to measure and set shim clearance during outboard maintenance. It is designed for 40 HP, V-8 applications with thru hub exhaust, giving technicians and do-it-yourself boaters an accurate way to check shim gaps without guesswork. Using the correct gauge bar helps ensure proper gearcase and exhaust housing clearances are set to specification, which supports smooth operation and helps prevent premature wear from an improperly shimmed assembly.

This tool is manufactured by Sierra, a long-standing supplier of marine engine parts and service tools, and is built as a direct equivalent to the OEM 349957 gauge bar. At 0.22 pounds, it is a lightweight, compact tool intended to be kept in a service kit alongside other shimming and clearance-check tools.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-79814
• Product Type: Shim Gauge Bar
• Weight: 0.22 pounds
• Application: 40 HP, V-8 with thru hub exhaust
• OEM Cross-Reference: 349957

Fitment

• 40 HP
• V-8 with thru hub exhaust

Replaces (OEM)

• 349957

Frequently Asked Questions

What does the Sierra 18-79814 shim gauge bar do? It is a service tool used to measure and set shim clearance on 40 HP, V-8 applications with thru hub exhaust, helping ensure the gap is set to the correct specification during reassembly.

What does the Sierra 18-79814 replace? The Sierra 18-79814 shim gauge bar is a direct replacement for OEM part number 349957.

Is the Sierra 18-79814 a genuine Sierra part or aftermarket? It is manufactured by Sierra as a direct-replacement service tool for OEM part 349957, not a repackaged factory part.

What applications is the 18-79814 gauge bar designed for? Sierra lists this gauge bar for 40 HP, V-8 applications with thru hub exhaust.

How much does the 18-79814 shim gauge bar weigh? The Sierra 18-79814 shim gauge bar weighs 0.22 pounds.

Will the 18-79814 gauge bar work on engines without thru hub exhaust? Sierra specifies this gauge bar for 40 HP, V-8 applications with thru hub exhaust; no other applications are listed for part number 18-79814.

What is included when you order part 18-79814? Ordering Sierra 18-79814 gets you one shim gauge bar tool; no additional accessories are listed for this part number.

Can OEM part 349957 be cross-referenced directly to the Sierra 18-79814? Yes, Sierra part 18-79814 is listed as the replacement for OEM number 349957.

What material is the 18-79814 shim gauge bar made from? The material is not specified for the Sierra 18-79814 shim gauge bar.

How is the Sierra 18-79814 shim gauge bar used during a service job? The gauge bar is used to check and set shim clearance as part of the assembly process on 40 HP, V-8 units with thru hub exhaust, in place of the original 349957 tool.