# 21133671 Belt Tensioner | Genuine Volvo Penta Part

## 🔧 Product Description

A spring-loaded automatic belt tensioner for earlier D5/D7 accessory drives. The tensioner combines a calibrated torsion spring, pivot bearing and pulley arm to maintain belt tension as the belt stretches and engine speed changes.

## 🚤 Compatibility

Typically suits:

-   Volvo Penta D5A-B TA
-   Volvo Penta D5A-T
-   Volvo Penta D7A-B TA
-   Volvo Penta D7A-T
-   Volvo Penta D7C-B TA
-   Volvo Penta TAD732GE EDC4
-   Volvo Penta TAD733GE EDC4

-   **Engine Family:** D, TAD

## ⚙️ Key Features

-   Automatic spring tensioning
-   Current service replacement for 20450764
-   Integral pivot and damping mechanism
-   Matched to the original belt length and pulley layout
-   Used on TAD520/TAD720 and related D5A/D7A applications
-   Engine type: Earlier D5/D7-series industrial or generator diesel

## 🔌 Function

Maintains the specified belt preload and absorbs transient belt vibration so the alternator, fan and coolant-pump drive remain stable.

## ⚠️ Common Signs of Failure

-   Cracking, glazing or rib/sidewall wear
-   Squeal or chirp during acceleration
-   Rough pulley bearing or abnormal tensioner movement

## 🛠️ Service Notes

-   Renew the belt whenever the tensioner is changed, and check every pulley in the drive for roughness, wobble or a seized bearing at the same time
-   Wind the tensioner back with the correct tool on the drive provided for it; do not lever on the arm or on the pulley, and release it onto the belt under control
-   Check that the arm swings freely over its whole travel and returns smoothly, and that the mounting face and any dowel or locating pin are clean so the pulley sits square
-   Tighten the mounting bolt to the figure in the workshop manual for your engine — an incorrectly tightened tensioner bolt is a common cause of repeat belt failures
-   Run the engine and confirm the belt tracks central on every pulley with no flutter of the tensioner arm

## 🔄 Supersession & Cross Reference

### OEM Supersession Chain

-   21133671 → Supersedes 20450764

### OEM / Related Numbers

-   20450764 earlier number superseded by this part

## 📦 Condition

-   Genuine Volvo Penta part
-   Brand new
-   Supplied in original or equivalent packaging

## Details

- **Price:** 290.54 AUD
- **Vendor:** Volvo Penta
- **Tags:** Volvo Penta

## Variants

| Variant | Price | Available |
|---------|-------|-----------|
| Default Title | 290.54 AUD | In stock |

## Images

- 21133671 Belt Tensioner | Genuine Volvo Penta Part

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> Source: [Sawley's Auto and Marine](https://www.sawleysautoandmarine.com.au/products/21133671-belt-tensioner-genuine-volvo-penta)
> Updated: 2026-08-22