# 31330321 Main Bearing | Genuine Volvo Penta Part

## 🔧 Product Description

Genuine Volvo Penta red-coded upper main bearing without flange, from the Engine group, weighing 0.043 kg and listed for 70 D series engine applications. It consolidates earlier references 31251577 and 31251378, and the workshop manual gives the selection procedure.

## 🚤 Compatibility

-   **Engine Family:** D
-   **HP Range:** 110-220 HP

Full model list at the end of this description.

## ⚙️ Key Features

-   Red colour code
-   Upper shell, without flange
-   0.043 kg
-   Consolidates 31251577 and 31251378
-   70 D series engine applications
-   5 used per assembly

## 🔌 Function

Provides the upper main bearing shell that carries the crankshaft in the block.

## ⚠️ Common Signs of Failure

-   Deep rumble from the bottom end under load
-   Low oil pressure, worst when hot
-   Overlay worn through to the shell backing
-   Metal debris in the oil and on the filter
-   Crankshaft main journals scored or out of round

## 🛠️ Service Notes

-   Four colour grades are catalogued for the upper unflanged position — red, yellow, blue and green — and the colour is the size grade, so follow the workshop manual procedure
-   Matching lower shells are separate parts, so order upper and lower by their own numbers
-   Main bearing failure usually points at oil supply, so find the cause before rebuilding

## 🔄 Supersession & Cross Reference

### OEM Supersession Chain

-   31330321 → Supersedes 31251577

## 📦 Condition

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

## 🔎 Full Model Compatibility

Typically suits:

-   Volvo Penta D3-110I-B, D3-110I-C, D3-130I-C, D3-220I-G, D3-130A-A, D3-160A-A, D3-130A-B, D3-160A-B, D3-130A-C, D3-160A-C, D3-140A-D, D3-170A-D, D3-200A-D, D3-220A-D, D3-140I-D, D3-140A-E, D3-170A-E, D3-200A-E, D3-220A-E, D3-140I-E, D3-140A-F, D3-170A-F, D3-200A-F, D3-220A-F, D3-140I-F, D3-140A-G, D3-170A-G, D3-200A-G, D3-220A-G, D3-140I-G, D3-190A-B, D3-190A-C, D3-190I-A, D3-110I-A, D3-130I-A, D3-160I-A, D3-110I-D, D3-150I-D, D3-170I-D, D3-200I-D, D3-220I-D, D3-110I-E, D3-150I-E, D3-170I-E, D3-200I-E, D3-220I-E, D3-110I-F, D3-150I-F, D3-170I-F, D3-200I-F, D3-220I-F, D3-110I-G, D3-150I-G, D3-170I-G, D3-200I-G, D3-110I-H, D3-160I-C, D3-190I-B, D3-190I-C, D3-140A-H, D3-170A-H, D3-200A-H, D3-220A-H, D3-130I-B, D3-160I-B, D3-150I-H, D3-170I-H, D3-200I-H, D3-220I-H, D3-140I-H

## Details

- **Price:** 38.43 AUD
- **Vendor:** Volvo Penta
- **Tags:** Volvo Penta

## Variants

| Variant | Price | Available |
|---------|-------|-----------|
| Default Title | 38.43 AUD | In stock |

## Images

- 31330321 Main Bearing | Genuine Volvo Penta Part

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> Source: [Sawley's Auto and Marine](https://www.sawleysautoandmarine.com.au/products/31330321-main-bearing-genuine-volvo-penta)
> Updated: 2026-08-22