Pic. 96. Camshaft drive mechanism assembly: 1 - crankshaft sprocket; 2 - chain tension shoe; 3 - chain tensioner; 4 - camshaft drive sprocket; 5 - chain damper; 6 - fuel pump drive sprocket; 7 - chain damper; 8 — the lever of a tension of a chain of a drive of the oil pump; 9 - oil pump drive sprocket
Pic. 95 a. Camshaft drive chain tensioner: 1 - cork; 2 - plug gasket; 3 - ball; 4 - spring seat; 5 - pressure spring; 6 - finger; 7 - unloading valve; 8 - sealing ring; 9 - ball; 10 - pressure spring; 11 - push rod; 12 - retaining ring; 13 — a bolt of fastening of an asterisk on a camshaft; 14 - washer of the sprocket mounting bolt on the camshaft; 15 — a bolt of fastening of an asterisk on a camshaft; 16 - chain lock; 17 - shoe for chain tension; 18 - shoe support pin; 19 - sealing gasket of the chain tensioner on the cylinder head; 20 - chain tensioner
The position of the tension shoe of the drive chain is shown in fig. 95 a and 96. To replace the drive chain tensioning shoe, it is necessary to dismantle the cylinder head and the cover of the camshaft drive mechanism. The synthetic shoe cover cannot be replaced, so the shoe assembly must be replaced when the cover wears out. The process of replacing the chain tensioner shoe must be carried out as follows:
- dismantle all parts that create an obstacle to free access to the front of the engine. The battery must be disconnected;
- remove the cylinder head (see subsection 2.4.1);
- remove the cover of the camshaft drive mechanism (see subsection 2.5);
- paint marks on the crankshaft sprocket and drive chain;
Pic. 99. Marks on the camshaft drive sprocket and drive chain
- mark the camshaft sprocket and drive chain (pic. 99);
Pic. 100. Fixing the camshaft drive sprocket
- unscrew the fixing bolt of the camshaft drive sprocket, having previously fixed it from turning. You can fix and hold the sprockets from turning with the help of a mandrel (pic. 100);
- dismantle the camshaft drive sprocket;
- tilt the tension shoe inward and remove it from the support pin;
- check the degree of wear or damage to the synthetic coating and, if necessary, replace the shoe;
- install the shoe in the reverse order of removal. Tighten the camshaft drive sprocket bolt. Tighten the bolt with a torque of 25 Nm, and then tighten it another 85–95°while holding the camshaft from turning. When installing the drive chain, make sure that the paint marks on the drive chain and both sprockets match up.