21890407 Timing Gear Plate | Genuine Volvo Penta Part

🔧 Product Description

Engine timing-gear plate used on selected D9 and D11 marine configurations. Machined bores and mounting faces position the idler, camshaft and auxiliary gears so valve timing and accessory drive alignment remain correct.

🚤 Compatibility

Typically suits:

• Volvo Penta D11B3-A MP
• Volvo Penta D11B4-A MP
• Volvo Penta D11B2-A MP
• Volvo Penta D11B1-A MP
• Volvo Penta D9A2L MH
• Volvo Penta D9A2M MP

• Engine Family: D

⚙️ Key Features

• Precision-machined gear and idler locations
• Maintains specified gear centre distances
• Rigid support for timing and auxiliary drive
• Factory oil passages and sealing faces
• Engine-build and

🔌 Function

Supports and aligns the engine timing gears and associated idlers at the specified centre distances.

⚠️ Common Signs of Failure

• Timing-gear noise or uneven tooth contact
• Excessive idler end float
• Oil leakage from the timing case
• Cracked or distorted plate
• Accelerated gear and bearing wear

🛠️ Service Notes

• Clean both faces completely and check the plate for flatness before refitting; this seals against a machined face, so any sealant ridge or burr will leak oil
• Take care of the locating dowels or bushes — the plate positions the timing components, so it must go back on its locations rather than be centred on its bolts
• Renew the gasket and any seal carried in the plate, and apply sealant only where the workshop manual for your engine specifies
• Tighten evenly in stages to the manual's figures and sequence, then turn the engine over by hand and check the timing gears run freely with the correct backlash before starting
• Have the front seal and a full gasket set to hand before you begin — the plate rarely comes off without disturbing the parts around it

🔄 Supersession & Cross Reference

OEM Supersession Chain

• 21890407 → Supersedes 3886444 → Supersedes 3835908

OEM / Related Numbers

• 3886444 earlier number superseded by this part
• 3835908 earlier number superseded by this part
• 20849147 - camshaft idler gear
• 21012985 - hub
• 8131850 - thrust washer
• 22356360 - power-steering idler gear
• 21509055 - idler gear
• 21663213 - gear
• 8148139 - oil-pump gear
• 8148198 - gear
• 3161258 - gear

📦 Condition

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