11997812 Screw | Genuine Volvo Penta Part

🔧 Product Description

A genuine Volvo Penta crank-mechanism screw used to secure the crankshaft pulley or vibration-damper assembly on MD22 and TMD22-family marine diesel engines. Four screws are used in the applicable MD22L crankshaft pulley assembly. Correct grade, length and tightening torque are essential because the fasteners transmit crankshaft torsional and accessory-drive loads.

🚤 Compatibility

Typically suits:

• Volvo Penta TMD22B
• Volvo Penta TMD22P-C
• Volvo Penta TAMD22P-B
• Volvo Penta MD22L
• Volvo Penta MD22P

• Engine Family: TMD, TAMD, MD
• HP Range: Approximately 50-78 HP
• Year Range: Approximately 1990s

⚙️ Key Features

• OEM Volvo Penta part number 11997812
• System group: Engine
• Net weight: 0.014 kg
• Replaces superseded part number 859637
• Fits MD22, TMD22 and TAMD22 series marine diesel engines
• Supplied as a single screw
• Engine type: Volvo Penta / Perkins-derived 2.0L inline 4-cylinder marine diesel

🔌 Function

The screw secures engine components together at a specified clamping load, holding mating parts in correct alignment. Correct fastener specification is important to maintain joint integrity under engine vibration and thermal cycling.

⚠️ Common Signs of Failure

• Corrosion or pitting of the head or threads from saltwater exposure
• Stripped, galled or cross-threaded threads preventing correct torque
• Rounded or damaged head making removal with the correct tool impossible
• Loss of clamping force causing looseness, vibration or leaks at the joint
• Stretched or snapped shank following over-torquing or repeated reuse

🛠️ Service Notes

• Clean the threads in the casting and check them for damage before fitting; a screw run into a dirty or pulled thread gives a false torque reading and will not hold its load
• Tighten to the torque given in the workshop manual for your engine rather than by feel, and follow the specified sequence where the joint has one
• Use the thread locking or sealing compound the manual calls for at that joint — some screws pass into oil, coolant or fuel space and have to seal as well as clamp
• Renew any screw that is stretched, corroded in the shank, or has damaged threads or a rounded head, and never reuse one that was tightened by a stretch or angle-tighten procedure
• A little marine-grade anti-seize helps later removal where the manual permits it, but keep it off threads that are meant to take a locking compound

🔄 Supersession & Cross Reference

OEM Supersession Chain

• 11997812 → Supersedes 859637

OEM / Related Numbers

• 859637 earlier number superseded by this part
• 3581328 related crankshaft kit
• 3581332 related crankshaft pulley
• 859764 related spacer
• 861592 related spacer
• 859765 related locking component
• 861593 related locking component

📦 Condition

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