Mercury - Double-Wound Split Lock Washer - 13-33734
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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Alternate/Superseded Part Numbers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. ⚓
Shipping information
In-stock and OEM parts: ship same or next business day.
Locally warehoused items: ship within 3–4 business days.
Special-order items: timeline confirmed after order.
Returns & warranty
Returns & Satisfaction Guarantee
We stand firmly behind the quality of every product we sell. Your confidence matters to us — and we back it with a straightforward 30-Day Satisfaction Guarantee.
If you are not fully satisfied, you may request a return within 30 days of delivery. All returns must receive pre-approval prior to being sent back. Unauthorized returns will not be accepted.
To qualify for a return:
Item must be in new, unused condition
Product must be in its original packaging
All parts, components, hardware, manuals, and accessories must be included
Packaging must be undamaged and suitable for resale
Important:
Electronics are strictly inspected. No returns on open-box electronics. Exceptions may apply only with prior written approval. Any electronic unit that has been installed, powered, activated, or altered may not be eligible for return.
We are serious about product integrity — and equally serious about taking care of our customers. If there is ever a product issue, contact us immediately so we can make it right.
For return authorization, please contact our support team before shipping anything back.