Volvo Penta Six Point Socket Screw 984257 | 25 mm | DPH DPR Sterndrive

Part Details

• Part Number: 984257
• Brand: Volvo Penta
• Type: Six point socket screw (internal hex / socket head cap screw)
• Length: 25 mm
• System: DPH / DPR sterndrive housing/center tube assembly and shift mechanism
• Qty Per Assembly: 4 (housing and center-tube assembly on applicable drives)
• Weight: Approx. 0.05 kg
• Important: Several similar six-point socket screws are used in the same sterndrive at different lengths confirm the correct length and diagram position before ordering. Do not substitute by appearance alone.

About This Part

Genuine Volvo Penta 984257 is a 25 mm OEM six-point socket screw used in selected Volvo Penta DPH and DPR sterndrive assemblies. Parts manuals place 984257 in more than one position within these drives including the housing and center-tube assembly (4 required) and the shift mechanism on applicable models. Because Volvo Penta uses several nearly identical socket screws of different lengths in the same sterndrive, the correct part must be matched by both part number and the specific diagram position being serviced. Do not select by appearance or socket size alone, as screws 984260 (18 mm), 984298 (20 mm), 984257 (25 mm), and 984258 (40 mm) all look similar on the bench but occupy different positions with different torque requirements.

Compatible Applications

Diagram-confirmed:

• Volvo Penta DPH-A / DPH-B housing/center tube assembly and shift mechanism
• Volvo Penta DPR-A / DPR-B housing/center tube assembly and shift mechanism
• Volvo Penta DPH-D1 housing/center tube assembly
• Volvo Penta DPR-D shift mechanism assembly

Confirm drive model, serial number, and exact diagram position before ordering. 984257 is used in more than one assembly location within the same drive torque specifications must be taken from the applicable Volvo Penta workshop procedure for the specific assembly being serviced, not inferred from screw size alone.

Socket Screw Length Reference Same Drive Family

• 984260 18 mm (different position)
• 984298 20 mm (different position)
• 984257 25 mm (this part)
• 984258 40 mm (different position)

These are different-length screws at different diagram positions not interchangeable substitutes.

When to Replace

Replace this screw if it shows any of the following:

• Damaged or rounded socket engagement from incorrect tool use
• Stretched or damaged threads
• Severe corrosion affecting thread integrity or seating surface
• Damage to the head or bearing surface
• Removal from a critical assembly where the applicable service procedure specifies replacement rather than reuse

Installation Notes

Use the correct hex key to avoid rounding the socket. Inspect mating threads and the surrounding assembly before installation and confirm the specified screw length is correct for the diagram position being serviced. Torque to the specification in the applicable Volvo Penta workshop procedure for the exact assembly torque values differ between the housing/center-tube position and the shift-mechanism position even though the same screw length is used.

Cross-Reference Part Numbers

• OEM: 984257 (25 mm six point socket screw)
• Note: No confirmed Volvo Penta OEM superseding number identified.

Parts Desk Insight

984257 is the 25 mm socket screw in the DPH/DPR drive family, and the most common issue is ordering the wrong length because several nearly identical screws are used throughout the same drive at 18 mm, 20 mm, 25 mm, and 40 mm. Matching by the exact part number and the diagram position rather than by socket size or visual inspection is the only reliable method. Also worth noting: 984257 appears in more than one assembly location within the same drive, so the torque specification must come from the workshop procedure for the specific assembly being serviced, not from a general fastener chart.