Cars with ZMZ-4025 and ZMZ-4026 engines are usually equipped with a lever-type clutch with a peripheral arrangement of springs or a reinforced clutch with a diaphragm spring

For cars with engines ZMZ-406 and ZMZ-405, only a clutch with a diaphragm spring is installed.

The clutch release drive is the same for both types of clutches.

Only the working cylinder is located on the ZMZ-402 engines on the left side of the clutch housing, and on the ZMZ-405, ZMZ-406 on the right side.

- Cause of malfunction

Remedy

Incomplete disengagement of the clutch - the clutch “leads” (gears do not engage or engage with difficulty):

- When the engine is idling, the direct gear is engaged and the clutch is disengaged, the secondary shaft of the gearbox should not rotate

To carry out the test, the driveline must be removed and a separate sliding driveline yoke must be inserted into the rear gearbox housing to prevent oil leakage

- The presence of air in the hydraulic clutch

Bleed the hydraulic system of the clutch drive, make sure that the movement of the fork end is at least 14 mm

- Jamming of the hub of the driven disk on the splines of the input shaft

Remove jamming on splines (clean splines)

- Warping of the driven disk

Replace the driven disk or straighten it

- Non-simultaneous pressing of the clutch release bearing on the clutch release levers

Adjust the relative positions of the ends of the clutch release levers

Incomplete engagement of the clutch - the clutch slips (a specific smell is felt, the acceleration of the car worsens, the speed drops, it is difficult to overcome the slope):

- Weakening of pressure springs

Replace springs with new ones

- Oiling the friction linings of the driven disk

Replace the driven disc or friction linings.

In case of slight oiling, wash the surface of the linings with kerosene and clean with fine sandpaper

- Excessive wear of the friction linings (to the rivets), the working surfaces of the flywheel and the pressure plate

Replace friction linings or driven disc

Replace the flywheel or pressure plate or remove scoring and ring marks on them by machining, taking into account the recommendations

- The compensation hole of the master cylinder is clogged or blocked by the edge of the cuff due to swelling of the cuff

Rinse the master cylinder with working fluid or replace the cuff

Unsmooth clutch engagement:

- Oiling the friction linings of the driven disk

Replace friction linings

- Wear of friction linings (before rivets)

Replace driven disc or friction linings

- Jamming of the hub of the driven disk on the splines of the input shaft of the gearbox

Remove spline jam

- Non-simultaneous pressing of the clutch release bearing on the levers

Adjust the relative position of the levers

- Loss of elasticity of the leaf springs of the driven disk

Replace driven disk

- Jamming of the clutch release levers in the supports or the protrusions of the pressure plate in the casing windows

Remove jamming (smooth mating surfaces)

Vibrations and noises in the transmission while driving:

- Breakage or wear of parts of the damper device of the driven disk

Replace driven disc assembly

- Wear of the friction washer or weakening of the pressure spring of the friction damper

Replace friction washer or damper spring

"Squeak" and noise in the clutch when the engine is running:

- Failure of the clutch release bearing

Replace the bearing. Check and realign clutch housing and crankshaft

Squeaking when pressing the clutch pedal when the engine is not running:

- There is no lubrication or the plastic bushings of the clutch pedal axle are worn out

Lubricate plastic bushings with a colloidal graphite preparation (OST 08-420-74) or replace worn bushings with new ones

Clutch disengagement occurs only when the pedal is pressed hard. When gently pressed, the pedal easily reaches the stop, the clutch does not turn off:

- Pollution or heavy wear of the master cylinder mirror. Excessive wear of the master cylinder piston cuff

Rinse and replace the master cylinder if worn. Change cuff

Lower fluid level in clutch master cylinder reservoir:

- Wear or hardening of the cuff of the piston of the working cylinder - fluid leakage

Replace cuff

- Violation of the tightness of the pipeline connection with the main and working cylinders - fluid leakage

Tighten connection Nuts