20859656 Cover | Genuine Volvo Penta Part

🔧 Product Description

A genuine Volvo Penta upper cylinder-head cover for the D5/D7 valve-train assembly. The cover encloses the rocker mechanism, contains lubricating-oil splash and protects the valve train from dirt and water while providing the original mounting and gasket interface.

🚤 Compatibility

Typically suits:

• Volvo Penta TAD560VE
• Volvo Penta TAD561VE
• Volvo Penta TAD734GE
• Volvo Penta TAD765VE
• Volvo Penta TAD764VE
• Volvo Penta TAD763VE
• Volvo Penta TAD762VE
• Volvo Penta TAD761VE

• Engine Family: TAD

⚙️ Key Features

• Genuine Volvo Penta Cylinder Head / Rocker Mechanism Cover - part number 20859656
• Moulded or cast OEM cover matched to the cylinder-head sealing rail
• Encloses rocker arms, valve springs and upper valve-train hardware
• Contains lubricating-oil splash and crankcase vapour within the engine
• Original bolt pattern and breather/access openings where specified
• Designed to clear the moving rocker mechanism at all operating conditions
• Fit with the correct gasket and tighten in the specified sequence to avoid distortion
• Engine type: D5/D7-series industrial and generator diesel cylinder heads

🔌 Function

The cover forms the serviceable upper enclosure of the cylinder head. It keeps oil inside the engine, prevents foreign material entering the valve train and provides a controlled interface for any breather, filler or wiring features incorporated in the cover installation.

⚠️ Common Signs of Failure

• Oil leakage around the cover perimeter
• Cracks around fastener bosses or hose connections
• Warped sealing rail from overtightening
• Damaged breather or filler interface
• Internal contact marks caused by an incorrect or distorted cover

🛠️ Service Notes

• Clean both sealing faces back to clean metal and check the cover for distortion, cracks or pulled bolt holes before refitting — a warped flange will not seal even with a new gasket
• Where the joint uses a gasket, seal or O-ring, always fit a new one and seat it dry unless the workshop manual for your engine specifies a sealant; never try to make a poor joint tight with extra sealant
• Tighten the fasteners progressively and evenly, working out from the centre, to the figure given in the manual for your engine — pressed steel, alloy and plastic covers distort easily if pulled down hard or unevenly
• If the cover carries a shaft seal or bearing, support it square to the shaft as it goes on so the seal lip is not nicked or rolled over
• Check that any breather, drain or oil return passage in the cover is clear before final tightening, and look for leaks once the engine has been run up to temperature

🔄 Supersession & Cross Reference

OEM Supersession Chain

• 20859656 → Supersedes 20902400

OEM / Related Numbers

• 20902400 earlier number superseded by this part

Other-Brand OEM Numbers

• VOE20859656

📦 Condition

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