# 20405797 Support Ring | Genuine Volvo Penta Part

🔧 Product Description

  

Genuine Volvo Penta Alternator Support / Back-Up Ring - Part Number: 20405797

  

Genuine Volvo Penta support ring used in an alternator mounting and pulley-retention assembly. This component is also known as a back-up ring or plain support washer.

  

⚙️ Key Features

  

• Alternator support or backing ring

• Function group 3219 - alternator mounting hardware

• Supports the pulley, spacer or mounting interface

• Distributes load and maintains the specified spacing

• Must be installed in the original orientation and position

  

🔄 Supersession & Cross Reference

  

OEM Supersession Chain:

  

• 20405797 - current Volvo Penta support/back-up ring reference

  

OEM / Related Numbers:

  

• 21801402 - related alternator in one documented arrangement

• 20460360 - related alternator bracket

• 20593398 - related tensioner

• 20593394 - related pulley

  

Aftermarket / Verified Equivalents:

  

• No aftermarket equivalent

  

🚤 Compatibility

  

Commonly used on:

  

• Volvo Penta alternator mounting and pulley assemblies

  

Typically suits:

  

• Engine / equipment models:

• Volvo Penta alternator assemblies using support ring 20405797

  

• Engine Type: Alternator-specific Volvo Penta diesel applications

• Year / Serial Range: Alternator, bracket and pulley configuration dependent

  

🔌 Function

  

Provides the required support, spacing or load distribution within the alternator mounting or pulley assembly.

  

Common signs of failure:

  

• Pulley or bracket axial play

• Washer/ring grooving or deformation

• Alternator misalignment

• Repeated belt wear

• Loose or incorrectly spaced mounting

  

📦 Condition

  

• Genuine Volvo Penta part

• Brand new

• Supplied in original or equivalent packaging

## Details

- **Price:** 6.68 AUD
- **Vendor:** Volvo Penta
- **Tags:** Volvo Penta

## Variants

| Variant | Price | Available |
|---------|-------|-----------|
| Default Title | 6.68 AUD | In stock |

## Images

- 20405797 Support Ring | Genuine Volvo Penta Part

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> Source: [Sawley's Auto and Marine](https://www.sawleysautoandmarine.com.au/products/20405797-support-ring-genuine-volvo-penta)
> Updated: 2026-07-30