21521991 Steering Knuckle | Genuine Volvo Penta Part

🔧 Product Description

A genuine heavy-duty steering knuckle used in a Volvo Penta marine steering assembly. The approximately 7.3kg casting forms a principal pivot and load-bearing connection between the steering mechanism and the associated drive or steering structure.

🚤 Compatibility

• Engine Family: D, IPS
• HP Range: 260-435 HP

Full model list at the end of this description.

⚙️ Key Features

• Genuine Volvo Penta steering knuckle
• Heavy-duty marine steering casting
• Provides the main steering pivot and structural connection
• Machined bearing, bushing and fastener locations
• Direct replacement for a cracked, bent or excessively worn original knuckle
• Engine type: Volvo Penta marine propulsion steering system

🔌 Function

Transfers steering force through the pivot assembly while supporting the drive-side loads and maintaining controlled steering geometry.

⚠️ Common Signs of Failure

• Excessive steering play or wandering
• Stiff, notchy or uneven steering movement
• Knocking at the steering pivot
• Visible cracking, corrosion or distortion
• Accelerated bushing, pin or seal wear from a damaged pivot bore

🛠️ Service Notes

• At around 7.3 kg this knuckle needs proper support while it is off the boat — do not let it hang on the steering linkage or pivot pin while working on it
• This is a steering component: any play, cracking or corrosion in the casting means renewal, not adjustment or repair
• Renew the mating pins, bushes and boots at the joint at the same time, grease the pivot on assembly, and check the whole steering linkage through full lock before the boat is used

🔄 Supersession & Cross Reference

OEM Supersession Chain

• 21521991 → Supersedes 3861694

OEM / Related Numbers

• 3861694 earlier number superseded by this part

Aftermarket / Verified Equivalents

• Approximate component weight: 7.325kg

📦 Condition

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

🔎 Full Model Compatibility

Typically suits:

• Volvo Penta D6-330D-E, D6-370D-E, D6-330D-C, D6-370D-C, D6-330D-D, D6-370D-D, D6-330D-F, D6-370D-F, D6-300D-F, D6-310D-D, D6-310D-C, D6-310D-E, D6-435D-D, D6-435D-E, D6-435D-F, D6-435D-C
• Volvo Penta D4-260D-C, D4-260D-D, D4-260D-E, D4-260D-F, D4-300D-C, D4-300D-D, D4-300D-E, D4-300D-F
• Volvo Penta IPS-A, IPS-B, IPS-C, IPS-D, IPS-E, IPS-F
• Volvo Penta 8.1IPSCE-MF, 8.1IPSCE-P, 8.1IPSCE-Q