Figure 140. Installing the poly V-belt on the pulley: 1 - pulley; 2 - poly V-belt
The drive of the coolant pump and generator is carried out by a single poly-V belt, which is installed on a pulley, as shown in the figure 140.
Figure 141. Tensioning mechanism device (for 2.9L engine): 1 — M8 bolt for fastening the damper to the cylinder head; 2 - washer; 3 - shock absorber; 4 — nut for fastening the spring lever to the cylinder head; 5 — spring lever; 6 - spring; 7 — spacer sleeve; 8 — spring mounting bolt; 9 — belt tension roller; 10 — tension roller mounting bolt on generator bracket; 11 — roller mounting plug; 12 - washer; 13 — sealing ring between the tension lever and the camshaft drive mechanism cover; 14 — tension roller lever; 15 — tension lever mounting pin on the camshaft drive mechanism cover; 16 — tension roller cover; 17 — M7 bolt for fastening the damper to the tension lever; 18 — tension roller mounting plug; 19 — tension roller mounting bolt on the lever; 20 — belt tension roller; 21 — tension roller mounting plug; 22 — bolt M8; 23 - guide roller; 24 — guide roller mounting bracket; 25 — bracket mounting bolt to cylinder block
Figure 142. Belt drive tensioning mechanism device (the damper can be removed separately without dismantling other parts): 1 - bolt; 2 — damper; 3 - bolt; 4 - nut; 5 — spring lever; 6 - spring; 7 — bolt; 8 — bolt; 9 — belt tension roller; 10 — bolt; 11 — plug; 12 - washer; 13 - tension lever; 14 — bolt; 15 — plug
The belt is kept in tension by a tension roller held by a spring. The installed damper prevents belt vibration. Figure 141 shows the individual components of the belt drive tensioning mechanism. Tension rollers are not interchangeable between different models. In the basic configuration, without additional units installed, the tension roller has the same groove width as the other pulleys. In other versions the roller surface is smooth. This should be taken into account when replacing. Figure 142 shows the entire tensioning mechanism. To access it, the front part of the engine must first be disassembled.
The belt drive should be checked every 20,000 km. To do this, make a mark on the belt in an accessible place with chalk. Turn the engine over with the starter at least one revolution. To prevent the engine from starting, press the fuel pump shut-off lever with a screwdriver. While turning the engine with the starter, inspect the belt along its entire length until the mark you made appears. Cracked, worn or burnt areas indicate the need for replacement.
To remove and install the drive belt, perform the following operations:
Figure 143. Drive belt tensioner mechanism parts: 1 - tension lever; 2 - nut; 3 - return spring; 4 - tension roller; 5 - plug; 6 — tension roller lever; 7 — damper; 8 - Upper damper mount
Figure 144. Weakening of the belt drive tensioner: 1 - spring; 2 - shock absorber; 3 - tension mechanism fastening
- loosen tension lever nut 1 (figure 143) and insert the rod into the tensioner lever as shown in the figure 144. For example, a metal rod with a diameter of 12 mm and a length of 180 mm can be used as a rod;
- press the rod slightly to the left to release the bolt;
- now press the rod slightly to the right, loosening the tension spring;
- press down on the tension roller so that the belt can be removed.
The belt is installed in the reverse order. First pass the belt through the tension roller, then put it on all pulleys in sequence. Lastly, the belt is placed on the coolant pump pulley. If the work has been carried out correctly, the belt will be installed in a tensioned state.
Removal and installation of the belt tensioning mechanism is performed in the following sequence:
- free the front of the engine to access the mechanical parts;
- remove the drive belt as described above;
- remove tension lever 5 (see figure 142) springs and spring 6. When assembling, install the spring with the color mark facing up;
Figure 145. Location of the tensioner damper (unscrew only from the cylinder head)
- unscrew the damper from the cylinder head (figure 145);
- remove plug 15 (see figure 142) and unscrew bolt 1 of tension lever 13. When unscrewing bolt 14, press the tension lever in the direction opposite the plug. Before reinstalling, thoroughly clean the threads of bolt 1. Apply sealant to the threads of bolt 1. Before installing the tension lever on bolt 1, lubricate the space between the bearing bushings of the lever;
- remove tension lever 13 together with damper 2 from tension roller 9. Do not lose washer 12;
- disconnect damper 2 from tension lever 13. When replacing the damper, release the air by pressing the rod several times. The damper is installed with the rod down, as shown in the figure 142;
- remove plug 11, unscrew bolt 10 and remove tension roller 9 from tension lever 13.
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Assembly is carried out in the reverse order, taking into account the following tightening torques (Nm):
- tension roller to tension lever - 30;
- tension lever - 100-110;
- damper to the cylinder head - 21;
- damper to tension arm - 20;
- tension lever to the cylinder head - 21.