# 21509621 Roller Kit | Genuine Volvo Penta Part

🔧 Product Description

  

Genuine Volvo Penta Twin Disc MG5170 Flexible Coupling Roller Kit - Part Number: 21509621

  

A genuine eight-piece rubber roller set for the flexible coupling used with Twin Disc MG5170 marine transmissions.

  

⚙️ Key Features

  

• Eight matched rubber rollers

• For MG5170 connecting-component assemblies

• Reduces torsional vibration and transient driveline load

• OEM hardness and dimensional control

  

📋 Kit Contents

  

• 8 × rubber coupling roller - serviced under kit 21509621; individual rollers are not separately numbered

  

🔄 Supersession & Cross Reference

  

OEM Supersession Chain:

  

• 21509621 current roller-kit reference

  

OEM / Related Numbers:

  

• Twin Disc MG5170 connecting components

• Related flywheel, companion flange and coupling hardware are ratio and engine-installation specific

  

Aftermarket / Verified Equivalents:

  

• No direct aftermarket equivalent verified

• Twin Disc coupling-service alternatives must be matched by coupling model, roller count, dimensions and elastomer hardness

  

🚤 Compatibility

  

Used on large Volvo Penta marine propulsion packages fitted with a Twin Disc MG5170 reversing gear, commonly D13 and D16-class installations.

  

• HP Range: approximately 700HP-1,000HP+

• Year Range: approximately 2000s-2010s

• Serial Range: MG5170 transmission and coupling serial controlled

  

🔌 Function

  

The rollers transmit torque through the flexible coupling while cushioning firing pulses, gear engagement shock and small alignment changes.

  

Common signs of failure:

  

• Rubber is cracked, flattened, oil-softened or missing

• Coupling knocks or rattles at idle

• Vibration increases during gear engagement

• Roller debris is found in the coupling housing

• Excessive coupling backlash develops

  

📦 Condition

  

• Genuine Volvo Penta part

• Brand new

• Supplied in original or equivalent packaging

## Details

- **Price:** 5382.08 AUD
- **Vendor:** Volvo Penta
- **Tags:** Volvo Penta

## Variants

| Variant | Price | Available |
|---------|-------|-----------|
| Default Title | 5382.08 AUD | In stock |

## Images

- 21509621 Roller Kit | Genuine Volvo Penta Part

---

> Source: [Sawley's Auto and Marine](https://www.sawleysautoandmarine.com.au/products/21509621-roller-kit-genuine-volvo-penta)
> Updated: 2026-07-29