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Crankshaft Bearing – Fits Yanmar 3JH3, 4JH3 Series Marine Engines (Replaces 129690-02800)

Sale price $27.58 Regular price $44.00
Shipping calculated at checkout.

Crankshaft Bearing – Fits Yanmar 3JH3, 4JH3 Series Marine Engines (Replaces 129690-02800) is backordered and will ship as soon as it is back in stock.


Worry-free returns

You may return most new, unopened items within 7 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).

You should expect to receive your refund within four weeks of giving your package to the return shipper, however, in many cases you will receive a refund more quickly. This time period includes the transit time for us to receive your return from the shipper (5 to 10 business days), the time it takes us to process your return once we receive it (3 to 5 business days), and the time it takes your bank to process our refund request (5 to 10 business days).

If you need to return an item, simply login to your account, view the order using the "Complete Orders" link under the My Account menu and click the Return Item(s) button. We'll notify you via e-mail of your refund once we've received and processed the returned item.

Delivery and Shipping

Free standard shipping on all orders under 1 KG

If you have any questions, feel free to email us at info@sierramarines.com, and we’ll get back to you within 20–36 hours.

Product Details

This high-quality Crankshaft Bearing – Fits Yanmar 3JH3, 4JH3 Series Marine Engines is designed for a precise fit in various Yanmar 3JH and 4JH series marine diesel engines. It serves as a critical internal component to ensure smooth crankshaft rotation and engine reliability.

It directly replaces Yanmar OEM part number 129690-02800.

  • Installation as an internal engine component.
  • Engineered for marine diesel environments.
  • Includes one crankshaft bearing.

Part Number Matrix

Use this matrix to confirm equivalent references across OEM and aftermarket.

Brand Part Number Notes
Yanmar 129690-02800 OEM Reference
Sea Sierra 129690-02800 Aftermarket Replacement

Engine & Model Compatibility

Confirm your engine model/year in the table below.

This bearing is designed for compatibility with the following Yanmar marine engines:

Brand Model Stroke OEM Part No. Notes
Yanmar 3JH3 4-Stroke 129690-02800
Yanmar 4JH3-DFTE 4-Stroke 129690-02800
Yanmar 4JH3-HTE 4-Stroke 129690-02800
Yanmar 4JH3-TE 4-Stroke 129690-02800
Yanmar 3JHLP 4-Stroke 129690-02800 Auxiliary engine
Yanmar 4JHL-N 4-Stroke 129690-02800 Auxiliary engine
Yanmar 4JHL-TN 4-Stroke 129690-02800 Auxiliary engine
Yanmar 4JHYE 4-Stroke 129690-02800
Yanmar 4JH3-DT 4-Stroke 129690-02800
Yanmar 4JH3-DTZ 4-Stroke 129690-02800
Yanmar 4JH3-DTZA 4-Stroke 129690-02800
Yanmar 4JH3-DTZAY 4-Stroke 129690-02800 Electric generator
Yanmar 3JH3E(EPA) 4-Stroke 129690-02800 Electric generator
Yanmar 4JH3CE 4-Stroke 129690-02800 Electric generator
Yanmar 3JH3Z1 4-Stroke 129690-02800
Yanmar 4JH3-TCE 4-Stroke 129690-02800
Yanmar 3JH25A 4-Stroke 129690-02800
Yanmar 3JH30A 4-Stroke 129690-02800
Yanmar 4JH3-TZA 4-Stroke 129690-02800

Technical Specs

Product Type
Crankshaft Bearing
Installation
Internal Engine Component
Dimensions
Height: 7.0 cm, Width: 6.0 cm, Length: 5.0 cm
Weight
0.05 kg (0.11 lb)

What’s in the Box

  • 1 x Crankshaft Bearing (129690-02800)

Installation Notes

  1. Disconnect the battery and ensure the engine is completely cool before starting work.
  2. Drain the engine oil and remove the oil pan to access the crankshaft.
  3. Carefully remove the bearing caps, making sure to note their original position and orientation.
  4. Remove the old, worn crankshaft bearings from the engine block and caps.
  5. Thoroughly clean the crankshaft journals and bearing saddles, ensuring they are free of oil, debris, and burrs.
  6. Apply a generous amount of fresh engine assembly lube to the surfaces of the new bearings.
  7. Install the new bearing shells into the engine block and bearing caps.
  8. Carefully place the crankshaft back into position and reinstall the bearing caps.
  9. Torque the bearing cap bolts to the precise specifications listed in your engine's service manual.
  10. Check for proper, smooth crankshaft rotation by hand.
  11. Reinstall the oil pan, using a new gasket, and refill the engine with the correct grade and amount of new oil.
  12. Reconnect the battery. After starting the engine, immediately check for oil leaks and verify correct oil pressure.

Troubleshooting & FAQ

How can I verify this bearing fits my Yanmar engine?

Please check your engine model against the "Engine & Model Compatibility" list on this page. It is also critical to verify that your existing part number matches the OEM reference 129690-02800.

What are common symptoms of a worn crankshaft bearing?

Signs include a deep knocking or rumbling sound from the engine (especially under load), low oil pressure warnings, and the presence of metallic particles or shavings in the engine oil during an oil change.

Is special tooling required for this installation?

Yes, professional installation is highly recommended. The process requires specific tools like a calibrated torque wrench, bearing pullers, and precision measuring instruments like micrometers for checking clearances.

What is the recommended service interval for a crankshaft bearing?

Crankshaft bearings do not have a fixed replacement schedule. They are typically inspected and replaced during a major engine overhaul or if signs of failure are diagnosed through symptoms like engine noise or low oil pressure.

Is this a main bearing or a connecting rod bearing?

This is a crankshaft main bearing, which is responsible for supporting the crankshaft within the engine block.

Do I need to lubricate the bearing before installation?

Absolutely. It is critical to apply a generous amount of high-quality engine assembly lube to all surfaces of the bearing and the crankshaft journal before installation to prevent metal-to-metal contact and premature failure on startup.

OEM vs. Aftermarket?

This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.

Shipping speed & cost

We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.

Warranty & returns

Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). See our policy page or reach out for instructions.

Safety & Important Info

  • Verify images/specifications vs your original part. If anything differs—even if your model appears compatible—do not purchase.
  • This is an aftermarket replacement, not an OEM component.
  • Professional installation is recommended for safety and performance.

About Sea Sierra

  • Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
  • Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
  • Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.

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Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.

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