# A1580 Mackay 5/8 x 4 UNF Greaser Load Sharing Bolt | Marine Trailer Part

🔧 Product Description

  

Genuine Mackay Marine Trailer Products Greaseable Load-Sharing Spring Bolt 5/8" × 4" - Part Number: A1580

  

A heavy-duty 5/8" × 4" UNF suspension bolt for Mackay load-sharing and Rocka spring systems. The drilled grease passage and nipple allow lubricant to be delivered to the bush.

  

⚙️ Key Features

  

• 5/8" × 4" UNF high-strength suspension bolt

• Designed for load-sharing spring pivots

• Supports replaceable nylon or steel bushes

• Greaseable internal passage

• Grease-nipple orientation: straight grease nipple

  

📏 Specifications

  

• Nominal size: 5/8" × 4" UNF

• Lubrication: Greaseable

• Nipple angle: straight grease nipple

• Grip length, thread length and shank diameter must match the hanger and bush

  

🔄 Cross Reference & Related Parts

  

• 90-degree greaseable version: Mackay A1572

• Non-greaseable version: Mackay A1570

  

🚤 Compatibility & Application

  

• Compatible Mackay load-sharing or Rocka suspension pivot using the exact bolt dimensions

• Use with the correct bush, washers and locking nut

• Do not tighten against the threaded section where the suspension pivots

• Greaseable bolts require periodic lubrication with compatible chassis grease

  

🔌 Function

  

Forms the suspension pivot between the spring, rocker arm or hanger and carries shear load while allowing controlled rotation.

  

Common signs of wear, damage or replacement required:

  

• Bolt is bent, worn or grooved

• Threads are stretched or damaged

• Grease passage or nipple is blocked

• Bush has worn through to the bolt

• Suspension develops knocking or excessive lateral movement

  

📦 Condition

  

• Genuine Mackay Marine Trailer Products part

• Brand new

• Supplied in original or equivalent packaging

## Details

- **Price:** 25.8 AUD
- **Vendor:** Mackay
- **Tags:** Mackay Boat Trailers | Marine Trailer Parts & Accessories

## Variants

| Variant | Price | Available |
|---------|-------|-----------|
| Default Title | 25.80 AUD | In stock |

## Images

- A1580 Mackay 5/8 x 4 UNF Greaser Load Sharing Bolt | Marine Trailer Part

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> Source: [Sawley's Auto and Marine](https://www.sawleysautoandmarine.com.au/products/a1580-mackay-5-8-x-4-unf-greaser-load-sharing-bolt-1)
> Updated: 2026-08-05