Sierra Marine Power Steering V-Belt 18-15520 | 52 in. / 132.1 cm × 29/64 in. / 11.5 mm
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Sierra Marine Power Steering V-Belt 18-15520
- Part Number: 18-15520 (Sierra)
- Brand: Sierra
- Product Type: Marine V-Belt — Power Steering
- Effective Length: 52 in. / 132.1 cm
- Top Width: 29/64 in. / 11.5 mm
- UPC: 030999566690
The Sierra 18-15520 is a marine V-belt primarily used as a power-steering drive belt on selected MerCruiser and OMC inboard and sterndrive engines. High-strength synthetic cords resist stretching and shock loading. Rubber sidewalls maintain positive, non-slip pulley contact, and the construction is suited to the continuous-duty demands of a marine power-steering circuit.
Compatible Applications
Verified MerCruiser applications with high-mounted power-steering pump configurations:
- MerCruiser 230 / 5.0L MIE — selected 1981–1987
- MerCruiser 230 / 5.0L — selected 1983–1987
- MerCruiser 5.0L — selected 1988–1995
- OMC sterndrive applications specifying OEM belt 912714 / 0912714
Always confirm engine model, serial number, existing OEM belt number, power-steering pump location, and pulley configuration before ordering. Engines of the same displacement may use different belt lengths depending on the power-steering pump position, alternator, and production year. This belt should not be selected by engine displacement alone.
Cross-Reference Part Numbers
- Sierra: 18-15520
- Supplier/Catalogue Reference: 47-15520
- Mercury / MerCruiser: 57-33170
- Mercury Quicksilver: 57-33170Q
- Mercury / MerCruiser: 57-34359
- Mercury / MerCruiser: 57-37619
- Mercury Quicksilver: 57-37619Q
- Mercury / MerCruiser: 57-37619T
- OMC: 912714 / 0912714
- OMC: 0509287
- OMC: 0509288
- OMC: 0909818
- Mallory: 9-55001
When to Replace This Belt
- Cracks visible along the belt body
- Frayed or worn edges
- Glazed, hardened, or oil-contaminated surface
- Power-steering belt squeal at start-up or under load
- Slipping or loss of tension
- Belt has stretched beyond adjustment range
Installation Notes
- Inspect the power-steering pulley and all accessory pulleys for wear, corrosion, and alignment
- Check adjustment hardware and bracket condition
- Confirm correct belt routing before fitting
- Do not force the belt over pulley flanges with sharp tools
- Set belt tension to the engine manufacturer’s specification
- Rotate the system by hand to confirm full pulley seating
- Recheck tension after initial operation
Parts Desk Insights
Best use case: This is the go-to replacement for pre-season service on MerCruiser 305 and 350 V8 boats with a high-mounted power-steering pump. If your engine specifies OEM references 57-33170, 57-37619, or OMC 912714, this is the direct replacement. It also makes a sensible onboard spare — a belt failure on this circuit can take out power steering, raw water cooling, and battery charging at the same time.
Common issue: This belt is tied to a specific power-steering pump location and pulley layout, not just an engine size. Customers frequently order by displacement and end up with a belt that is the right length but wrong for their accessory arrangement. Always verify the OEM belt number and power-steering pump position before ordering. If your engine has been retrofitted with a different pump location or converted to a serpentine drive, this belt may not apply.
For a complete cooling system service, pair this belt with a raw water pump impeller. See the PCM Impeller Kit RP061017 and PCM / Crusader RP061022 Raw Water Pump Impeller for compatible options.
Need a different belt size? Browse other sizes in the Sierra V-Belt series: Sierra V-Belt 47-15400, Sierra V-Belt 47-15410, Sierra V-Belt 47-15440, Sierra V-Belt 47-15450, Sierra V-Belt 47-15455, Sierra V-Belt 47-15460, Sierra Marine V-Belt 18-15470, Sierra Marine V-Belt 18-15480, and Sierra V-Belt 47-15550.
Shop all Engine Parts & Maintenance or browse Propulsion & Powertrain for related components.
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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