A1590 Mackay 19mm x 85mm UNF Centre Rocka Arm Greaser Bolt | Marine Trailer Part

🔧 Product Description

Genuine Mackay Marine Trailer Products Centre Rocka-Arm Greaseable Pivot Bolt 19 × 85mm UNF - Part Number: A1590

A heavy-duty greaseable centre-pivot bolt for the Mackay Rocka load-sharing arm. The drilled lubrication passage supplies grease to the centre bush while the 19mm shank carries tandem-suspension shear loads.

⚙️ Key Features

• Heavy-duty centre-pivot bolt
• 19mm nominal shank diameter
• Approximately 85mm grip/length reference
• UNF thread
• Integrated grease passage and nipple

📏 Specifications

• Nominal diameter: 19mm
• Nominal length: 85mm
• Thread form: UNF
• Application: Centre Rocka/load-sharing arm
• Nut, washers and grease nipple are included only where stated

🔄 Cross Reference & Related Parts

• Centre Rocka arm: Mackay A1585G
• Steel pivot bush: Mackay A1578

🚤 Compatibility & Application

• Compatible Mackay Rocka centre-arm and hanger assembly
• Use the matching bush and locking nut
• Align the grease passage so lubricant reaches the pivot surface
• Grease at scheduled intervals and after water immersion where applicable

🔌 Function

Forms the main pivot for the load-sharing rocker arm and delivers grease to the centre bush.

⚠️ Common Signs of Failure

• Bolt is bent, grooved or seized
• Grease passage or nipple is blocked
• Threads are damaged
• Centre arm has excessive side play
• Bush has worn through to the bolt

📦 Condition

• Genuine Mackay Marine Trailer Products part
• Brand new
• Supplied in original or equivalent packaging