Sierra 18-15410 Cogged V-Belt — Marine Inboard & Sterndrive Accessory Drive
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Sierra 18-15410 Cogged V-Belt — Marine Inboard & Sterndrive Accessory Drive
Part Number: 18-15410 | SKU: 47-15410
Brand: Sierra
System: Accessory Drive / Raw-Water Pump & Alternator Belt
Supplied as: One (1) replacement belt
The Sierra 18-15410 is a precision-moulded cogged marine V-belt built to replace OEM belts on MerCruiser sterndrive and Volvo Penta inboard accessory-drive systems. High-strength synthetic tension cords keep stretch to a minimum over the belt's service life, while the open cog profile reduces operating temperature and improves flex around smaller-diameter pulleys. Specially compounded rubber distributes drive loads evenly and maintains positive contact with pulley grooves — the kind of belt you want running your raw-water pump and alternator every time you leave the dock.
Specifications
- Effective length: 41 inches / 104.1 cm
- Top width: 29/64 inch / 11.5 mm
- Profile: Cogged V-belt
- Construction: High-strength synthetic tension cords, compression rubber, rubber-edge sidewalls
- Weight: ~100 g (0.22 lb)
Key Features
- Open cog profile improves flexibility and reduces heat buildup during extended running
- Low-stretch synthetic cords maintain consistent drive tension between service intervals
- Rubber edge construction maintains positive contact with pulley groove sidewalls
- Drop-in OEM replacement — no modifications required
Compatible Applications
- MerCruiser sterndrive models specifying OEM belt numbers 57-49043, 57-49043A1, 57-64032, 57-64032A1, 57-64032Q1, or 57-816544
- Volvo Penta inboard and sterndrive models specifying OEM belt number 950813
- Accessory-drive positions including alternator, raw-water circulation pump, and power-steering pump depending on engine and pulley configuration
Serial Number Fitment Notice
Confirm the engine model, serial-number range, original OEM belt number, and accessory-drive arrangement before ordering. Engines within the same family can use different belt lengths and widths depending on the alternator specification, power-steering option, pulley layout, and production year. A belt that matches the approximate length can still be the wrong part for your pulley system.
Supersedes / Cross-Reference
- Sierra: 18-15410
- Mallory: 9-55004
- MerCruiser: 57-32850, 57-49043, 57-49043A1, 57-64032, 57-64032A1, 57-64032Q1, 57-816544
- Mercury: 57-98043
- Volvo Penta: 950813
Service Interval
Inspect at every 100-hour service or annually, whichever comes first. Replace immediately if you find cracking, glazing, frayed edges, missing cog material, oil contamination, or excessive stretching. Squealing, slipping, repeated loss of tension, or a belt riding unusually low in the pulley groove are signs of wear, misalignment, or an incorrect belt profile — do not delay replacement.
Installation Notes
Inspect all pulleys for wear, corrosion, contamination, and misalignment before fitting the new belt. Do not force the belt over pulley flanges. Set tension to the engine manufacturer's specification, rotate the drive by hand to confirm correct seating, and recheck tension after the first operating period.
Related Parts
- Other sizes in this series:
- Cooling system service (pair with this belt):
Technical FAQ
Q: How do I know if this is the correct belt for my engine?
A: Cross-reference your OEM belt number with the supersedes list above. If your engine specifies 57-49043, 57-64032, 57-816544, or Volvo Penta 950813, this is the direct replacement. If your OEM number is not in that list, check the other sizes in the series linked above or contact us with your engine model and serial number.
Q: Can one V-belt drive both the alternator and raw-water pump?
A: On many MerCruiser and Volvo Penta configurations, a single belt drives multiple accessory-drive pulleys. Confirm your specific pulley layout against the engine service manual before ordering a replacement.
Q: What happens if I install a belt that is slightly too long or too short?
A: An incorrect-length belt will either over-tension or under-tension the drive, leading to accelerated wear, pulley damage, belt slipping, or loss of raw-water cooling. Always verify the OEM part number before installation.
Q: Should I replace the belt during a raw-water pump impeller service?
A: Yes — if the pump is accessible during impeller replacement, it is good practice to replace the drive belt at the same time, especially if it has not been changed in the last two seasons.
Parts Desk Insights
Best use case: This belt is the right pre-season choice for MerCruiser sterndrive and Volvo Penta owners who need a reliable OEM-spec replacement for the accessory drive. If your engine specifies any of the MerCruiser 57-series or Volvo Penta 950813 belt numbers listed above, this is the confirmed direct replacement. It also makes practical sense as an onboard spare for extended cruising — a belt failure on an inboard can simultaneously take out raw-water cooling and battery charging, leaving you stranded.
Common customer issues: The most frequent inquiry is customers ordering by approximate length without confirming the OEM belt number — a close-enough length is not always the right profile or width for the pulley system. Always ask the customer to confirm the OEM belt number and engine serial range before dispatching. Customers pairing this with a raw-water pump impeller service should also be offered the PCM Impeller Kit RP061017 or PCM / Crusader RP061022 Impeller depending on their pump model.
Shipping information
In-stock and OEM parts: ship same or next business day.
Locally warehoused items: ship within 1-3 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.
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