Description

The Mercury Quicksilver Double-Wound Split Lock Washer 13-33734 is an OEM heavy-duty lock washer used in select MerCruiser high-vibration mounting and flywheel applications. Its double-wound spring profile helps maintain clamping tension on critical hardware where engine vibration, torque load, and alignment stability matter.

Key Features

• Genuine Mercury/Quicksilver double-wound split lock washer
• Part number: 13-33734
• Also referenced as 33734
• 1/2″ inside diameter
• Heavy-duty spring-style locking washer
• GTIN / UPC: 0745061079199
• Used in select rear engine mount, transom plate, flywheel, and coupler hardware locations

Engine Compatibility

Used on select MerCruiser sterndrive and inboard/outboard applications where this washer is shown in the rear engine mount, flywheel, or coupler parts diagram.

Serial Number Fitment Notice

Verify fitment by engine serial number, mount/flywheel diagram, and original hardware stack-up before ordering. Mounting hardware can vary by engine package, transom assembly, flywheel housing, coupler style, and production range.

When This Part Needs Replacement

Replace this washer if it is flattened, cracked, badly corroded, distorted, missing, or removed during critical engine mount or flywheel service. Lock washers that have lost spring tension should not be reused in high-vibration locations.

Installation Notes

Install in the correct order shown in the Mercury parts diagram. Inspect the related studs, nuts, mount pads, fiber washers, coupler hardware, and alignment components before reassembly. Follow Mercury service procedures for torque specifications and engine alignment.

Alternate/Superseded Part Numbers

Replaces Mercury 33734A1 and 33021. Primary references: 13-33734 and 33734.

Parts Desk Insight

This washer is small, but it is part of the hardware stack that helps keep alignment-critical fasteners tight. Replacing worn lock washers during mount or flywheel service is cheap insurance against vibration-related loosening.

Shipping: Ships same or next day for fast Canada wide shipping.