Timing Components: Description and Operation

TIMING DRIVE

Primary Drive:
To facilitate precision optimization with regard to noise, weight and friction, the primary drive is transmitted via a single roller chain (M60: double roller chain) from the crankshaft to the inlet camshaft. The primary drive sprockets are rubberized to enable low-noise engagement of the chain.

Camshaft Sensor Wheel:



A sensor wheel with 4 sensor markings for identifying cylinder number 1 (DME) is mounted on the inlet camshaft sprocket for cylinders 1-4. In contrast to the M60 (inductive position sensor), a hall sensor is used as the camshaft position sensor on the M62 engine.

Due to the new design of the camshaft position sensor wheel, positioning of the sensor wheel for the camshaft drive has also been newly defined. The camshaft sensor wheel now features a mark (notch). Particular care must be taken during assembly to ensure that this mark faces downward with respect to the cylinder axis.

Deflection Rail For Primary Chain:



The detection wheel in the V-chamber has been replaced on the M62 by an aluminium deflection rail with clip-on plastic track The chain is tensioned by means of a hydraulic chain tensioner with a pressure limiting facility.

Due to the use of a deflection rail (instead of the deflection wheel), during assembly of the primary drive, modified torque values for pretensioning the rail must be observed.

Secondary Drive:
The secondary drive is also based on a single roller chain. It extends from the inlet camshafts to the exhaust camshafts.

A hydraulic chain tensioner is integrated on each cylinder head

Timing Case Cover:
As on the M60, the timing case covers are attached at the cylinder heads and at the central crankcase.

The sealing system is new:

The two upper timing case covers are sealed with respect to the cylinder head and the lower timing case cover by means of a rubber formed gasket. This rubber formed gasket achieves better tolerance compensation and acoustic decoupling between the lower and upper timing case covers.

Due to the use of the modified gasket, a new procedure for assembling the upper timing case cover must be observed in order to achieve the optimum sealing effect. Refer to assembly not in repair instructions!

The lower timing case cover is sealed with respect to the crankcase by means of a flat gasket.