Raw Water Pump Coupler Cross Piece for Volvo Penta Diesel Engines – Replaces 858467, Sierra 18-3175

Product Details

This raw water pump coupler cross piece is a single replacement component for specified Volvo Penta marine diesel engines. It connects the raw water pump to the pump drive assembly and transfers drive rotation to the pump. The component is listed as a replacement for Volvo Penta part number 858467 and corresponds to Sierra water pump coupler 18-3175.

Use the compatibility list below as a model reference only. Confirm the original coupler, pump assembly, and engine identification before ordering, because model variants and pump configurations can differ.

• Raw water pump coupler cross piece
• Installs between the raw water pump and pump drive assembly
• Sold as one individual replacement component
• For specified Volvo Penta D, AD, AQAD, MD, TAMD, TMD, KAD, KAMD, and D300-series engines

Part Number Matrix

The following references identify this coupler component in the available manufacturer and aftermarket catalog data.

Engine & Model Compatibility

The catalog fitment references include the following Volvo Penta engine models. The catalog does not establish a universal year range or serial-number range, so verify the exact engine and pump configuration before installation.

Technical Specs

Component

Raw water pump coupler cross piece

Function

Transfers drive rotation from the pump drive assembly to the raw water pump

Application

Specified Volvo Penta marine diesel engines

Primary Reference

Volvo Penta 858467

Aftermarket Reference

Sierra 18-3175

Product Type

Single replacement component; not a complete water pump assembly

What's in the Box

• 1 × Raw Water Pump Coupler Cross Piece

Installation Notes

1. Stop the engine, allow it to cool, and follow the engine manufacturer's safety procedures before servicing the raw water pump.
2. Close the seacock or otherwise prevent water from entering the vessel while the raw water circuit is open.
3. Remove the raw water pump according to the applicable Volvo Penta service procedure.
4. Separate the pump from its drive assembly and remove the old coupler cross piece.
5. Inspect the pump drive interface, pump shaft, seals, and related components for wear or damage.
6. Install the replacement cross piece in the correct orientation and reassemble the pump.
7. Use the manufacturer's torque specifications for all fasteners; do not substitute a generic torque value.
8. Reopen the seacock, check for leaks, and verify raw-water flow after starting the engine.

Troubleshooting & FAQ

What does this part do?

This cross piece is a mechanical coupler between the raw water pump and its drive assembly. It allows the drive assembly to rotate the pump.

Is this a complete raw water pump?

No. This listing is for one coupler cross piece only. It does not include the complete pump, cover, impeller, gasket, drive assembly, or other pump-service parts.

Which part numbers does it replace?

The available catalog information identifies Volvo Penta 858467 as the replacement reference and Sierra 18-3175 as the water pump coupler reference.

What are common signs of a worn coupler?

Possible symptoms include a raw water pump that does not turn correctly, reduced cooling-water flow, overheating, abnormal pump noise, or visible wear, cracking, or deformation when the pump is disassembled. Inspect the complete drive and pump assembly before replacing the coupler.

How can I confirm fitment?

Compare your engine model and original component with the references and model list on this page. Also verify the pump-drive design and dimensions before ordering. A model match alone does not confirm every year, serial number, or pump configuration.

Is this an OEM part?

This listing is for an aftermarket replacement component. Volvo Penta 858467 and Sierra 18-3175 are reference numbers used to identify the applicable part.

Safety & Important Information

• Always shut down and cool the engine before servicing the raw water pump.
• Prevent water ingress while opening the raw water circuit and check carefully for leaks after installation.
• Verify the original part, pump configuration, engine model, and service-manual requirements before ordering.
• Professional installation is recommended when pump-drive alignment or engine service procedures are unfamiliar.

About Sea Sierra

• Marine replacement parts for engine cooling and raw-water systems.
• Clear reference-number and fitment information to support accurate part selection.
• Customer support for product and installation questions.