Fig. 91. Elements of the valve timing drive: 1 - intermediate shaft; 2 - leading ring; 3 - bolt, 10 Nm; 4 - sensor drive; 5 - bolt, 10 Nm; 6 - bolt, 25 Nm; 7 - elastic element of the tensioning device; 8 - double-row chain tensioner, 20 Nm; 9 - double row chain; 10 - double-row chain drive sprocket; 11 - single-row chain drive sprocket; 12 - chain tensioner with shoe; 13 - chain drive sprocket built into the crankshaft; 14 - single row chain; 15 - damper bar; 16 - special bolt, 25 Nm; 17 - pin with flange, 25 Nm; 18 - sedative; 19 - bolt, 20 Nm; 20 - crankshaft sprockets
The camshafts are not driven directly, but through the intermediate shaft gear 1 (Fig. 91).
In addition, a small sprocket 10 is located on the intermediate shaft, which drives the double-row chain 9 of the camshaft drive. On the VR6 engine, sprocket 13 on the front end of the crankshaft, which drives the single-row chain 14, is non-removable (removed together with the crankshaft).
The specified tension of the double-row chain, driving the camshafts, is carried out by a plate chain tensioner (tensioner) 8, which is adjusted using an externally inserted chain tension adjusting bolt. The single-row chain between crankshaft sprocket 13 and intermediate sprocket 11 also has a tensioner 12, which is adjusted hydraulically and does not require any additional intervention. It should be remembered that the chain tensioner has a locking device that must be unlocked before changing the chain tensioner. The double-row drive chain is pressed from the outside inward by the damper 18, which prevents the drive chain from hitting the camshafts. The single-row chain is also pressed by the damper 12, but the chain is pressed from the inside out. Bolts and special pins are used to secure the dampers.
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