Cylinder Head Gasket – Fits Yanmar 3TNV84/3JH3 Marine & Komatsu 3D84E Engines (Replaces 129002-01331)
Cylinder Head Gasket – Fits Yanmar 3TNV84/3JH3 Marine & Komatsu 3D84E Engines (Replaces 129002-01331) is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
Free standard shipping on all orders under 1 KG
Cylinder Head Gasket – Fits Yanmar 3TNV84/3JH3 Marine & Komatsu...
Product Details
This Cylinder Head Gasket provides a direct-fit sealing solution for a range of Yanmar and Komatsu engines. It is engineered for Yanmar 3JH3 series marine engines and the versatile 3TNV84 industrial series. It also fits Komatsu construction equipment powered by the 3D84E engine series, ensuring a reliable seal between the cylinder head and engine block.
This part is a direct replacement for Yanmar part numbers 129002-01331, YM129002-01331, 12900201331, and YM12900201331.
- Installation Type: Direct replacement for a precise fit.
- Engine Compatibility: Designed specifically for 3-cylinder diesel engines.
- Function: Creates a critical seal for compression and fluid passages.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Yanmar | 129002-01331 |
| Yanmar | YM129002-01331 |
| Yanmar | 12900201331 |
| Yanmar | YM12900201331 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
For Yanmar owners: This gasket fits 3JH3 series marine engines and a wide array of 3TNV84 series industrial engines found in generators and other equipment.
For Komatsu owners: This part is compatible with various 3D84E series engines used in compact excavators, wheel loaders, and skid steer loaders.
| Brand | Model | Stroke | OEM Part No. | Notes |
|---|---|---|---|---|
| Yanmar | 3JH3 | 4-Stroke | 129002-01331 | Marine pleasure application |
| Yanmar | 3JH3E | 4-Stroke | 129002-01331 | Marine pleasure application |
| Yanmar | 3JH3CE | 4-Stroke | 129002-01331 | Marine pleasure application |
| Yanmar | 3TNV84-K5FD | 4-Stroke | 129002-01331 | |
| Yanmar | 3TNV84-BGKL | 4-Stroke | 129002-01331 | |
| Yanmar | 3TNV84-BGMG | 4-Stroke | 129002-01331 | |
| Yanmar | 3TNV84-BKSA2 | 4-Stroke | 129002-01331 | |
| Yanmar | 3TNV84-BMCU | 4-Stroke | 129002-01331 | |
| Yanmar | 3TNV84-BMNK | 4-Stroke | 129002-01331 | |
| Yanmar | 3TNV84-BXNK | 4-Stroke | 129002-01331 | |
| Yanmar | 3TNV84-DUW | 4-Stroke | 129002-01331 | |
| Yanmar | 3TNV84-DZP01/02/03 | 4-Stroke | 129002-01331 | Multiple DZP variants |
| Yanmar | 3TNV84-GDG | 4-Stroke | 129002-01331 | |
| Yanmar | 3TNV84-GGE | 4-Stroke | 129002-01331 | |
| Yanmar | 3TNV84-GKL | 4-Stroke | 129002-01331 | |
| Yanmar | 3TNV84-GMG | 4-Stroke | 129002-01331 | |
| Yanmar | 3TNV84-GKM | 4-Stroke | 129002-01331 | |
| Yanmar | 3TNV84-GYM | 4-Stroke | 129002-01331 | |
| Yanmar | 3TNV84-GZG01 | 4-Stroke | 129002-01331 | |
| Yanmar | 3TNV84-KMW | 4-Stroke | 129002-01331 | |
| Yanmar | 3TNV84-KSA/KSA2/KSA3 | 4-Stroke | 129002-01331 | Multiple KSA variants |
| Yanmar | 3TNV84-KUP | 4-Stroke | 129002-01331 | |
| Yanmar | 3TNV84-LUZ | 4-Stroke | 129002-01331 | |
| Yanmar | 3TNV84-MU2 | 4-Stroke | 129002-01331 | |
| Yanmar | 3TNV84-NBK | 4-Stroke | 129002-01331 | |
| Yanmar | 3TNV84-NU1 | 4-Stroke | 129002-01331 | |
| Yanmar | 3TNV84-Q1K/Q1KA | 4-Stroke | 129002-01331 | |
| Yanmar | 3TNV84-S1K | 4-Stroke | 129002-01331 | |
| Yanmar | 3TNV84-XKMR | 4-Stroke | 129002-01331 | |
| Yanmar | 3TNV84-XWL | 4-Stroke | 129002-01331 | |
| Komatsu | 3D84E-5Q-QB | 4-Stroke | ||
| Komatsu | 3D84E-5N-BA | 4-Stroke | ||
| Komatsu | 3D84E-5X-AB | 4-Stroke | ||
| Komatsu | S3D84E-5X-AC | 4-Stroke | ||
| Komatsu | S3D84E-5X-AB | 4-Stroke | ||
| Komatsu | S3D84-5X-AB | 4-Stroke | ||
| Komatsu | S3D84-5X-AC | 4-Stroke | ||
| Komatsu | 3D84E-3A/3B/3C/3D/3E/3F/3G | 4-Stroke | Multiple 3D84E-3 variants | |
| Komatsu | 3D84E-3K/3L/3LB/3LN/3M/3N/3Q | 4-Stroke | Multiple 3D84E-3 variants |
Komatsu Equipment Applications
| Brand | Model | Equipment Type | Notes |
|---|---|---|---|
| Komatsu | JV25CW-3, JV25DW-3 | Roller | |
| Komatsu | PC30MR-2/2-A/2-B/2-C/2-D | Excavator | Multiple PC30MR variants |
| Komatsu | PC35MR-2 | Excavator | |
| Komatsu | PC35R-8 | Excavator | |
| Komatsu | SK510-5, SR3000 | Skid Steer Loader | |
| Komatsu | SK815-5/5E0/5N/5NA | Skid Steer Loader | Multiple SK815 variants |
| Komatsu | SK820-5/5E0/5N | Skid Steer Loader | Multiple SK820 variants |
| Komatsu | WA30-5 | Wheel Loader | |
| Komatsu | WA40-3/3-CB/3-CN | Wheel Loader | Multiple WA40 variants |
| Komatsu | WA50-3/3CB/3-CN | Wheel Loader | Multiple WA50 variants |
Technical Specs
- Product Type
- Cylinder Head Gasket
- Installation
- Direct replacement
- Fuel Type
- Diesel
- Material
- Composite/Metal
- Dimensions
- 31.0 in L x 17.0 in W x 0.1 in H (78.7 cm L x 43.2 cm W x 0.25 cm H)
- Weight
- 0.35 lbs (0.16 kg)
- Other Attributes
- Critical sealing component between cylinder head and engine block
What’s in the Box
- 1 x Cylinder Head Gasket (Replaces 129002-01331)
Installation Notes
- Disconnect the battery and drain the engine coolant completely.
- Remove all components obstructing access to the cylinder head, such as the intake/exhaust manifolds, fuel lines, and wiring.
- Following the manufacturer's specified pattern, loosen and remove the cylinder head bolts in reverse order of the tightening sequence.
- Carefully lift the cylinder head from the engine block. Avoid using pry bars that could damage the mating surfaces.
- Thoroughly clean both the engine block deck and the cylinder head surface. Ensure they are free of old gasket material, oil, and debris.
- Place the new head gasket onto the engine block, ensuring it is correctly oriented. Do not use any sealant unless explicitly required by the gasket manufacturer.
- Carefully lower the cylinder head back into position over the dowel pins.
- Install and torque the head bolts in the correct sequence and to the manufacturer's specified torque values, often in multiple stages.
- Reassemble all previously removed components.
- Refill the cooling system, check engine oil, and reconnect the battery. Start the engine and check for any coolant or oil leaks.
Troubleshooting & FAQ
How do I know if my cylinder head gasket is failing?
Common signs of a blown head gasket include engine overheating, milky or discolored engine oil (coolant mixing with oil), white smoke from the exhaust (coolant burning in cylinders), loss of engine power, and bubbling in the radiator or coolant reservoir from leaking combustion gasses.
Do I need to use sealant with this gasket?
This gasket is designed to be installed dry. Applying sealants can interfere with its ability to seal correctly and may cause premature failure. Always follow the engine manufacturer's service manual for specific instructions.
What is the most critical part of the installation?
Surface preparation and proper torque procedure are the most critical steps. Both the cylinder head and engine block surfaces must be perfectly clean and flat. Bolts must be tightened in the exact sequence and to the torque specifications provided in your engine's service manual to ensure an even, lasting seal.
Will this fit an engine model not listed here?
We can only guarantee fitment for the models listed in the compatibility table. Using this gasket on other engines is not recommended, as even minor differences can lead to improper sealing, leaks, and catastrophic engine damage. Always cross-reference the OEM part number.
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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