Description

The Volvo Penta 3804451 is a genuine Volvo Penta OEM upper gear case core used in select Volvo Penta sterndrive upper gear housing service applications. The upper gear case is part of the drive section that transfers power from the engine coupler and U-joint/input shaft area into the vertical drive gear path. This is a major drive service component used where the Volvo Penta parts diagram or dealer parts system specifically calls for 3804451.

Key Features

• Genuine Volvo Penta factory OEM upper gear case core.
• Volvo Penta part number: 3804451.
• Major upper sterndrive gear housing service component.
• Used in select Volvo Penta upper gearcase rebuild, replacement, or core-exchange service situations.
• Supports the upper drive gear path where power is transferred from the input/U-joint area into the vertical drive system.
• Fitment depends on drive model, drive serial number, gear ratio, upper housing design, and Volvo Penta service documentation.
• May be subject to core-exchange requirements depending on supplier and ordering channel.

Application Compatibility

Common application context includes select Volvo Penta sterndrive assemblies by drive model, serial number, ratio, and upper gear housing configuration, including:

• SX-A / SX-B applications where specified
• DPS-A / DPS-B applications where specified
• DPH applications where specified
• DPR applications where specified
• Select gasoline and diesel Volvo Penta sterndrive packages using the matching upper gearcase core
• Upper gear housing service applications where the Volvo Penta parts system calls for 3804451

Use this core only where the Volvo Penta parts diagram, dealer parts lookup, or service procedure specifically calls for 3804451.

Fitment Notice

Confirm fitment by Volvo Penta drive serial number, exact drive model, gear ratio, upper gear housing configuration, and core-exchange requirements before ordering. Volvo Penta sterndrives can use different upper housings, gearsets, cone clutch components, shims, bearings, and seals across similar SX, DPS, DPH, and DPR drive families.

When This Part Needs Replacement

This type of core is normally considered during major upper gearcase service, drive rebuild work, or replacement after internal mechanical damage. Common reasons include damaged gearcase housing surfaces, bearing bore wear, spun bearing races, gear failure, severe corrosion, impact damage, overheating damage, or internal drive damage that cannot be corrected with normal seal, bearing, or gear replacement alone.

Installation Notes

Upper gearcase core replacement is a precision drive-service procedure. Inspect the input shaft, vertical shaft, upper gearset, cone clutch components, bearings, bearing races, shims, seals, retainers, and mating housings before assembly. Gear backlash, bearing preload, shim stack, gear contact pattern, and seal installation must be set according to the Volvo Penta service manual using the correct tools. Do not guess shim thickness or reuse damaged bearings, races, or sealing surfaces. Pressure/vacuum testing and final gear-lube inspection should be completed before the drive is returned to service.

Alternate/Superseded Part Numbers

• 3804451 — Volvo Penta upper gear case core

Parts Desk Insight

This is not a routine wear item like a seal or gasket. An upper gear case core is usually part of a major drive repair, and the correct choice depends on the complete drive identity, gear ratio, and internal parts configuration. Before ordering, confirm whether the supplier requires a reusable core return and whether the existing housing is acceptable for exchange credit.

Shipping: Ships same or next day for fast Canada wide shipping.