VAG 06B109088C GEAR ASSY CAMSHAFT
Product Specifications
| VAG | 06B109088C |
| VAG | 06B109088A |
| VAG | 06B109088D |
The GEAR ASSY CAMSHAFT is the sprocket or gear mounted on the camshaft nose that transmits rotational drive from the crankshaft via the timing chain or timing belt, maintaining precise phase relationship between the camshaft and crankshaft to synchronise valve opening events with piston position throughout the engine's operating cycle. On engines with fixed valve timing the gear is a simple pressed or bolted sprocket with a specific tooth count that defines the 2:1 reduction ratio between crankshaft and camshaft speed. On engines equipped with variable valve timing (VVT) — including Toyota VVT-i, Honda i-VTEC, BMW Valvetronic, and equivalent systems — the gear assembly incorporates a hydraulic phaser mechanism that rotates the camshaft relative to the sprocket body within a defined angular range in response to oil pressure controlled by the VVT solenoid valve, advancing or retarding valve timing to optimise power, torque, and fuel consumption across the engine's operating range.
This unit — VAG 06B109088C — is manufactured to OEM-equivalent specifications: tooth profile geometry and pitch, sprocket bore diameter and keyway or bolt pattern, phaser angular travel range and locking pin spring load where applicable, oil feed port diameter, and overall assembly concentricity tolerance are matched to the original part. Supplied as a direct replacement for standard fitment. Available wholesale from 33.48 USD, MOQ 50 pcs, production lead time 33 days.
Fixed camshaft sprockets wear through tooth flank erosion from chain contact under high-mileage and chain stretch conditions — a stretched chain accelerates sprocket wear by loading tooth flanks asymmetrically. VVT phaser assemblies fail through internal oil circuit contamination blocking the phaser vanes, locking pin spring fatigue preventing the phaser from locking at base timing on startup, and vane seal wear causing oil pressure bleed-off that prevents the phaser from holding a commanded timing position. Oil change discipline is the primary factor in phaser longevity — sludge from extended oil change intervals is the leading cause of premature VVT phaser failure across all manufacturers.
- Lock the engine at TDC on cylinder 1 compression stroke before removing any timing components — insert the crankshaft locking tool and all camshaft locking pins or plates specified in the OEM service procedure for this engine. Never rely on paint marks or visual reference alone; timing errors of one tooth on a camshaft sprocket will cause misfires, reduced power, and on interference engines, valve-to-piston contact resulting in catastrophic engine damage.
- Drain the engine oil and remove the timing cover to access the camshaft sprocket. On VVT phaser assemblies, clean the oil feed passages in the camshaft nose and cylinder head with compressed air before fitting the new phaser — sludge in the oil galleries that caused the original phaser failure will block the new unit within a short period if the passages are not thoroughly cleaned.
- Compare the new sprocket or phaser to the removed unit before installation — confirm tooth count, bore diameter, keyway orientation, and on VVT phasers, that the locking pin is present and spring-loaded correctly. Compress the locking pin manually to confirm it returns positively under spring pressure; a phaser with a weak locking pin spring will rattle on startup from the first cold crank.
- Install the camshaft sprocket with all timing locking tools in position and torque the centre bolt to OEM specification in the sequence specified — many camshaft sprocket bolts require a specific torque-plus-angle tightening procedure. Apply thread-locking compound only where specified by the OEM; incorrect application can prevent correct bolt stretch and cause the sprocket to work loose under load.
- Verify timing mark alignment with all locking tools in place before fitting the timing cover — rotate the engine by hand through two full crankshaft revolutions after removing the locking tools and reconfirm all timing marks return to the correct TDC position. If any mark is out of alignment, stop and re-check the tooth engagement before proceeding.
- Install the new GEAR ASSY CAMSHAFT (VAG 06B109088C), refit the timing cover with a new gasket and front crankshaft seal, refill with fresh engine oil of the correct specification, start the engine and check for timing chain noise and fault codes — clear any stored codes and verify with a scan tool that the VVT system is commanding and achieving the correct cam timing across the RPM range before returning the vehicle to service.