Removal and installation of the ZMZ-402 connecting rod-piston engine
- 1. Remove the cylinder head. (Cylinder head ZMZ-402 GAZ-3110)
- 2. Remove the oil pump.
- 3. Unscrew the nuts 1 of the connecting rod bolts and remove the connecting rod cover 2. Since the cover is tight, knock it down with light blows of a hammer.
Remove the connecting rod bearing shell from the cover.
- 4. Push the piston into the cylinder so that it comes out of the cylinder, and then remove it along with the connecting rod.
Remove the connecting rod bearing shell from the lower end of the connecting rod.
Remove the piston with the connecting rod from the cylinder carefully so as not to damage the cylinder mirror.
Check the marks on the connecting rod and connecting rod cap. If the marks are not visible, mark the connecting rod and cap with the cylinder number.
- 5. In the same way, remove the remaining pistons with connecting rods.
- 6. Using a puller, remove the piston rings.
7. Remove the circlips from both sides of the piston.
- 8. Press out the piston pins with a special tool.
If there is no fixture, you can knock out the piston pins with light hammer blows through the mandrel 1 - this must be done by weight so as not to damage the piston. Remove connecting rod 2 from piston 3.
- 9. In the same way, remove the remaining pistons from the connecting rods.
- 10. After disassembly, wash all parts in gasoline. Clean the pistons from carbon deposits.
Clean the piston ring grooves with an old piston ring or a broken ring.
Inspection, verification and repair of parts of the connecting rod and piston group are carried out similarly to operations on the engine mod. 406. Differences are shown below.
- 1. The clearance between the oil scraper ring and the groove on the piston must be between 0.135–0.335 mm.
- 2. The gaps in the locks of the piston rings should be within 0.3–0.7 mm for compression rings and 0.3–1.0 mm for oil scrapers.
- 3. Pins and connecting rods are marked with paint: a finger in a hole, a connecting rod on a rod near the upper head. The piston head is stamped with a Roman numeral showing the piston group.
The pin should not fall out of the connecting rod head when tilted at about 45°.
- 4. The difference in mass between pistons assembled with connecting rods, pins, piston rings installed on one engine should be no more than 12 g.
Build and install
The assembly and installation of the connecting rod and piston group are similar to those on the engine mod. 406.
When installing the nuts of the connecting rod bolts, lock them with Unigerm-9 sealant.