Sierra V-Belt 47-15400 | 40 in. Cogged Marine V-Belt | MerCruiser OMC
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Sierra V-Belt 47-15400
- Part Number: 47-15400 (Sierra catalog: 18-15400)
- Brand: Sierra
- Official Product Type: Cogged Marine V-Belt
- Effective Length: 40 inches / 101.6 cm
- Top Width: 29/64 inch / 11.5 mm
- Belt Style: Cogged (open-cog profile for flexibility and heat reduction)
- System: Engine accessory drive (alternator, raw water pump, power steering)
- UPC: 030999566454
What This Belt Does
The Sierra 47-15400 is a cogged marine V-belt for compatible MerCruiser, Mercury Marine, and OMC engine accessory-drive systems. High-strength synthetic cords resist shock loading and stretching. The moulded cog profile improves flexibility over pulley systems and increases airflow to reduce heat buildup. Specially compounded rubber distributes load evenly and rubber edges maintain positive pulley contact for consistent drive performance.
Compatible Applications
- Selected MerCruiser sterndrive accessory-drive systems specifying a 40-inch belt
- Mercury Marine inboard and sterndrive engines using OEM belt 57-32850
- MerCruiser engines using OEM belt 57-69143, 57-69143Q, or 57-69143T
- OMC / Johnson / Evinrude applications using OEM belt 311606 or 0311606
- Applications cross-referencing OMC 0509301 or Volvo Penta 3852106
Confirm the engine model, serial-number range, original OEM belt number, and accessory-drive configuration before ordering. Engines of the same displacement may use different belt lengths depending on the alternator, power-steering system, and pulley arrangement.
OEM Cross-Reference Numbers
- Sierra: 18-15400 / 47-15400
- Mercury Marine: 57-32850
- MerCruiser: 57-69143, 57-69143Q, 57-69143T
- OMC / Johnson / Evinrude: 311606, 0311606, 0509301
- Volvo Penta: 3852106
Service Interval
Inspect annually at seasonal service. Replace immediately if the belt is cracked, glazed, frayed, oil-soaked, or excessively stretched. A belt that rides low in the pulley groove, squeals, or slips under load should be replaced regardless of age — a failed belt can simultaneously disable raw water cooling and battery charging.
Installation Notes
- Inspect all pulleys for corrosion, wear, groove damage, and alignment before installing the new belt
- Do not force the belt over pulley flanges — route it on by hand
- Set belt tension to the engine manufacturer’s specification
- Rotate the drive by hand to confirm correct seating in all pulley grooves
- Recheck tension after the first operating period — new belts seat and may require re-tensioning
Technical FAQ
What is a cogged V-belt and why does it matter?
A cogged belt has moulded notches (cogs) on the inner face that allow it to flex more easily over smaller-diameter pulleys, run cooler, and grip more consistently than a smooth-back V-belt. Marine accessory-drive systems with compact pulley layouts benefit from the added flexibility.
Can I use a close-length belt if 47-15400 is unavailable?
No. A belt that is even slightly off in length will not tension correctly, will slip or squeal, and can cause premature wear to both the belt and pulleys. Always match the original OEM belt number or confirmed equivalent.
How do I know if belt slipping is the belt or the pulleys?
Inspect the pulley grooves for wear, glazing, or rust before fitting a new belt. A glazed or worn pulley will cause a new belt to slip immediately. If the old belt glazed, the pulleys likely contributed — clean or replace them before installing the replacement.
Related Parts
Other belt sizes in the Sierra 47-154xx series:
- Sierra V-Belt 47-15410
- Sierra V-Belt 47-15440
- Sierra V-Belt 47-15450
- Sierra V-Belt 47-15455
- Sierra V-Belt 47-15550
Pair with a raw water pump impeller for a complete cooling-system service:
Parts Desk Insights
This belt is the standard pre-season replacement for MerCruiser and OMC accessory-drive systems specifying a 40-inch belt. The most common issue is customers selecting by belt length alone without confirming belt width — a belt that is close in length but wrong in width will sit incorrectly in the pulley groove, causing slipping and accelerated wear. Always verify by OEM belt number, not just length. For extended cruising, carrying a spare 47-15400 is worthwhile: on many MerCruiser and OMC installations this single belt drives both the raw water pump and the alternator, so a failure leaves you with no cooling and no charging simultaneously.
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.
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.