Aftermarket Idler Pulley for MerCruiser Stern Drive & Outdrive – Replaces 864625T, 8183812, 818380T and 859135
Aftermarket Idler Pulley for MerCruiser Stern Drive & Outdrive – Replaces 864625T, 8183812, 818380T and 859135 is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
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Aftermarket Idler Pulley for MerCruiser Stern Drive & Outdrive ...
Aftermarket Idler Pulley for MerCruiser Stern Drive & Outdrive – Replaces 864625T, 8183812, 818380T and 859135 is backordered and will ship as soon as it is back in stock.
Product Details
This is an aftermarket idler pulley for selected MerCruiser stern-drive and outdrive applications. It is supplied as a single pulley assembly for use with the engine belt system. The company product record identifies this part as an idler pulley and lists the MerCruiser reference numbers shown below.
Use the reference numbers, pulley appearance, mounting arrangement and your engine or drive documentation to confirm compatibility before ordering. Application information for this individual pulley is not specified in the company fitment field, so the vehicle or engine model alone should not be treated as confirmation.
- Aftermarket idler pulley for marine belt systems.
- Intended for MerCruiser stern-drive and outdrive equipment.
- Supplied as one complete idler pulley assembly.
- Reference numbers include 864625T, 8183812, 818380T and 859135.
Part Number Matrix
The following manufacturer reference numbers are listed for this pulley. Number listings are reference information; confirm the complete application and physical match before installation.
| Brand or Reference | Part Number |
|---|---|
| MerCruiser | 864625T |
| MerCruiser | 8183812 |
| MerCruiser | 818380T |
| MerCruiser | 859135 |
Application Information
The company record categorizes this product for MerCruiser Stern / Out Drive applications but does not provide a model, year, horsepower, stroke, shaft-length or serial-number range for the individual pulley.
Some related belt-and-pulley combination records reference MerCruiser 4.3L, 5.0L, 5.7L and other V6/V8 applications, but those records describe separate combinations and are not transferred to this single-pulley listing. Verify the exact belt system and mounting configuration for your engine before purchase.
| Item | Information |
|---|---|
| Equipment family | MerCruiser stern drive and outdrive |
| Component | Idler pulley |
| Model, year, horsepower and serial range | Not specified for this individual pulley |
| Compatibility check | Match the reference number, original pulley and mounting arrangement before ordering |
Technical Specifications
- Product Type
- Idler pulley
- Product Format
- Single pulley assembly
- Application Category
- MerCruiser stern drive / outdrive belt system
- Reference Numbers
- 864625T, 8183812, 818380T and 859135
- Brand Status
- Aftermarket replacement
- Dimensions and Material
- Not specified in the company product record
What’s in the Box
- 1 x aftermarket idler pulley assembly
No belt, additional pulley, mounting hardware or installation tool is listed as included with this individual pulley.
Installation Notes
Installation procedures vary by engine and belt-system configuration. Always use the service information for your specific MerCruiser application and follow the manufacturer's torque requirements.
- Switch off the engine, isolate the starting system and allow all components to cool.
- Confirm that the replacement pulley matches the original pulley, reference number and mounting arrangement.
- Remove any guards or covers necessary to access the belt system, following the engine service instructions.
- Photograph or note the belt routing before removing the belt.
- Release belt tension using the procedure specified for your engine.
- Remove the belt from the pulley and remove the pulley mounting fastener.
- Install the replacement pulley in the same orientation as the original component.
- Reinstall and tighten the mounting fastener to the applicable manufacturer specification.
- Reinstall the belt according to the correct routing diagram and restore the specified belt tension.
- Rotate or inspect the belt system by hand, where permitted, to check alignment and free movement.
- Reinstall guards and covers before starting the engine.
- After installation, check for abnormal noise, belt wandering, vibration or pulley wobble.
Troubleshooting & FAQ
Is this a complete pulley or only a bearing?
This listing is for one idler pulley assembly. A separate bearing-only replacement is not listed as part of this product.
Does this listing include a belt?
No. The individual product record identifies a single idler pulley. The belt-and-pulley combinations found in the catalog are separate products and are not included here.
Which engines does this pulley fit?
The company record identifies the application category as MerCruiser stern drive and outdrive but does not specify a complete engine model, year, horsepower or serial-number range for this individual pulley. Confirm the reference number and physical configuration before ordering.
What are common signs of an idler pulley problem?
Possible signs include pulley wobble, rough or noisy rotation, belt tracking problems, abnormal belt wear and belt squeal. Inspect the complete belt system and follow the applicable service procedure before replacing parts.
Can I use the reference number alone to confirm fitment?
The reference number is an important cross-reference, but it should be checked together with the original pulley, mounting arrangement and the specific engine or drive configuration.
Is this an OEM part?
No. This is an aftermarket replacement pulley. MerCruiser reference numbers are provided only to help identify the corresponding application.
Shipping speed and cost
Shipping options, delivery estimates and applicable charges are displayed at checkout and may vary by destination.
Warranty and returns
Warranty coverage and return eligibility are governed by the current store policy. Contact customer support with your order details if you need assistance.
Safety & Important Information
- Do not rely on a general engine-family description alone. Confirm the exact reference number, pulley design and mounting arrangement.
- Disconnect the starting system and keep hands, clothing and tools away from moving belts and pulleys.
- Use the correct belt-routing information and manufacturer torque specifications for your engine.
- Replace or inspect related belt components if they show wear, contamination, misalignment or damage.
- This is an aftermarket replacement component, not an OEM component.
- Professional installation is recommended when the correct service procedure or fitment cannot be confirmed.
About Sea Sierra
- Pro-Grade Standards — We supply marine replacement parts selected for dependable service in demanding marine environments.
- Global Fulfillment — Shipping options are available for customers in many regions, with delivery details shown at checkout.
- Manufacturer-Direct Value — We aim to provide practical aftermarket replacement solutions at competitive prices.
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