During the operation of the car, the following malfunctions may occur: incomplete engagement (clutch slips) or partial disengagement (clutch drives).
If the clutch is not fully engaged with an increase in the engine speed, the car either (with the clutch pedal released) does not budge, or its speed increases very slowly,
In the cab, there is a smell of burnt friction linings of driven discs.
Slave drives are spinning as a result of:
- lack of clearance between the clutch release bearing and the thrust ring when the clutch pedal is released.
If there is no gap, the pressure plate is not fully pressed against the driven plate.
To eliminate this malfunction, ensure the clearance between the clutch bearing and the thrust ring by checking and adjusting the free play of the clutch pedal;
- oiling the clutch discs.
This malfunction occurs as a result of lubricant entering the cavity of the clutch housing through the seals of the input shaft of the gearbox or the rear end of the crankshaft of the engine, as well as excessive lubrication of the clutch release bearing.
The ingress of lubricant on the friction surfaces of the discs contributes to their slippage. The clutch must be removed and the discs washed with gasoline;
- wear of friction linings and friction surfaces of the flywheel of the middle drive and pressure plates. With a slight - wear of the linings, eliminate the malfunction by adjusting the free play of the clutch pedal.
In case of increased wear of linings, friction surfaces of the flywheel and discs, replace worn parts;
- shrinkage or breakage of pressure springs. Replace springs.
When the clutch is not completely disengaged, it is difficult to engage gears, accompanied by impacts of the teeth of the gears of the gearbox. A malfunction may occur for the following reasons:
- - the presence of a large gap between the clutch release bearing and the thrust ring. This is due to the fact that the clutch release actuator does not provide the necessary travel of the clutch fork shaft lever (reduced full travel, increased clutch pedal free play). The malfunction is eliminated by checking and adjusting the full or free travel of the clutch pedal;
- - skew or warping of the driven disk, uneven gap between the disks due to their warping, and in some places the absence of a gap. This most often occurs when the clutch overheats as a result of slipping. Fix the problem by replacing warped discs.
Destruction and breakage of friction linings. Pieces of the lining are wedged between the driven and driving disks and do not allow the cordon to be completely turned off. Replace damaged pads;
- skew pressure plate. When the clutch is disengaged, the pressure plate continues to be pressed against the driven disc with part of its working surface.
Remove the pressure plate with cover assembly, install on the fixture, check and adjust the position of the thrust ring.
Clutch removal
Remove the gearbox. Screw four tie bolts into the threaded holes of the bosses of the pressure plate 12 (Fig. 2)
8 until the heads of the bolts come into contact with the casing 10. Unscrew the bolts securing the clutch casing and remove the pressure plate 5 (see Fig. 1) complete with the casing.
Remove driven discs 3 and middle drive disc 2.
Adjusting the position of the clutch thrust ring. Install the pressure plate assembly with the casing on fixture 16 (see Fig. 2) or on the flywheel with an insert that provides an installation dimension "A" equal to 29 ± 0.1 mm.
Fix clutch cover 10 with bolts.
Loosen the tightening bolts 8 by unscrewing them two or three turns.
Unbend the edges of the locking plates 4 and unscrew the bolts 2.
Remove plates 4, 1 and lock washers 19.
Turn the nuts 3 to adjust the position of the thrust ring 7 of the release levers.
The “B” dimension after adjustment should be equal to 54 ± 0.3 mm, the runout of the end face T2 of the thrust ring relative to the end face T1 — no more than 0.4 mm.
In this case, the bearing surfaces of the ends of all pull levers 14 must simultaneously touch the thrust ring.
Adjusting the position of the thrust ring after installing the clutch on the engine is prohibited.
After completing the adjustment, install the (pre-straightened) lock washers 19. Install the opsupport plates 1, plates 4 and fix them with bolts 2.
Bend the ends of the locking plates 4, thus preventing the bolts 2 from unscrewing. Bend the lock washers 19 through the holes of the plates 4 and 1.
Tighten the tie bolts 8.
Remove the bolts securing the clutch cover and remove the pressure plate assembly with the cover from tool 16.
Disassembly of the pressure plate assembly with casing
Unbend the edges of the locking plates 4 and unscrew the bolts 2. Remove the plates 4, 1 and lock washers 19.
Install the pressure plate on the press and tighten the clutch cover 10. Unscrew the tie bolts 8 from the threaded holes of the bosses of the pressure plate.
Remove adjusting nuts 3.
Using a press, loosen the pressure springs and remove the clutch cover.
Remove the springs 9 and washers 11 mounted on the bosses of the pressure plate, together with the heat-insulating pads 13, as well as the thrust ring 7, the lock washers of the axles 18 connecting the release levers 14 with the pressure plate.
Knock out the axles and remove the lever assembly with forks 15 and springs 5.
Remove the rollers of the needle bearings from the holes of the levers.
Remove the lock washers of the axes 17 connecting the release levers with the forks 15, and the springs 5 together with the hinges 6.
Knock out axles 17 and remove the lever forks. Remove the rollers of the needle bearings from the holes of the levers.
The middle driving disk 2 (see Fig. 1) should be disassembled only if it is necessary to grind the working friction surfaces or to replace parts of the mechanisms for automatically adjusting the position of the disk.
Clutch housing disassembly
Unscrew the coupling bolt of the lever 19 (see Fig. 3) and remove the lever from the shaft of the clutch release fork.
Disconnect the hose 6 (see Fig. 1), springs 7 of the clutch release clutch and remove the clutch 8 from the guide cover of the bearing of the input shaft of the gearbox. Unscrew the grease fittings from the threaded holes in the clutch housing.
Unscrew the bolt 12 with a coupler and move the fork 9 along the shaft 11.
Remove the segment key from the groove - shaft.
Using a copper drift, knock out the shaft II of the clutch release fork together with the plug from the holes in the clutch housing.
If it is necessary to replace the bushings, press them out using a mandrel, having previously removed the parts of the oil seal of the clutch release fork shaft (cover, felt and rubber rings) from the hole of the left crankcase support.
Checking the technical condition and repair
Rinse the clutch parts after disassembly in kerosene, dry and determine their suitability for further operation.
In case of loosening of the hubs of the driven disks or friction linings, rivet the rivets or replace them with new ones.
If the driven disc damper springs break or the springs move axially in the disc holes, replace the driven disc assembly.
Replacement is also subject to:
- - friction linings of the driven disks in the presence of large scuffs, delamination or wear to rivets; pressure springs in the presence of cracks and breaks;
- - axes of pull levers with a brinelled working surface;
- - worn rollers of needle bearings. Dimensions of new friction linings and holes in them for rivets must correspond to those given in fig. 4.
When checking the condition of the parts, check the change in the elasticity of the clutch release clutch springs.
The tensile force of the spring to a length L = 115 mm must be at least 4.4 kgf.
The operation of the middle drive and pressure disks with through cracks and warping is not allowed.
At the same time, small thermal cracks on the friction surface of the discs are not a sign for culling.
Warping, scuffing, non-flatness and uneven wear of the friction surfaces of the middle drive and pressure disks can be eliminated by grinding.
The thickness of the metal removed when grinding the pressure plate should not exceed - 1.3 mm.
The thickness of the middle drive disc after grinding must be at least 23.66 mm.
If bushings 2 (Fig. 5) of the clutch release fork shaft are worn out over a diameter of 25.1 mm, replace the bushings.
Replace bushings with mandrels and a press.
When pressing, point the chamfered ends of the bushings towards each other, and align the holes in the bushings and crankcase bearings for lubrication.
Machin the inner surfaces of pressed bushings in a line to a diameter of 25+0.025.
Misalignment of machined bushing holes check with a caliber with a diameter of 24.99 mm.
The non-parallelism of the common axis of the bushings and the “T” end should be no more than 0.1 mm over a length of 100 mm.
In case of replacing the clutch release clutch bearing, press the new bearing against the stop of the inner ring into the end of the clutch.
Assemble the clutch housing and middle drive plate in the reverse order of disassembly.
When assembling the middle driving disk, apply Litol-24 lubricant to the friction surfaces of the axles and bushings of the release levers. After tightening the axes of the release levers, bend the lock washers on both sides.
After assembly, check the operation of the mechanisms for automatically adjusting the position of the middle drive disk.
When installing the disk on the plate with the release levers, the springs must not twist under the weight of the disk and must return the disk to its original position after pressing it until it comes into contact with the plate.
When installing lever 19 (see Fig. 3) on the splines of the clutch release fork shaft, make sure that the marked tooth of the lever enters the marked cavity of the shaft (marks b).
Assembly of pressure plate with casing
Parts must be dry and clean before assembly. When assembling, grease the spherical friction surfaces of the adjusting nuts 3 (see Fig. 2), the clutch cover 10, the release levers 14 and the working grooves of the thrust ring 7, as well as the rollers of the needle bearings, with Litol-24 lubricant.
In the process of assembling the pressure plate and adjusting the position of the thrust ring of the withdrawal levers, make sure that the working surfaces of tool 16 are clean.
Ingress of dirt and metal chips on the friction surface of the pressure plate and the flange of the clutch housing is unacceptable.
Assemble the pressure plate in the following order.
Place 20 rollers of the needle bearing of the axle 17 in the hole of the release lever 14.
To facilitate the assembly of the needle bearing, apply a thin layer of Litol-24 lubricant to the hole wall of the withdrawal lever and install six to eight rollers in the hole.
Then, insert a split textolite sleeve into the lever hole (Fig. 6) and install the remaining rollers.
When installing a new needle bearing, complete it with rollers of the same size group.
Aligning the holes of the fork 15 (see Fig. 2) and the lever 14, insert the axle 17, while pushing the split sleeve out of the holes of the lever and the fork.
Similarly, using a split sleeve, assemble the second needle bearing and install the release lever into the groove of the pressure plate boss.
Aligning the hole of the lever with the holes of the boss, insert the axle 18, while pushing the split sleeve out of the holes of the lever and the boss.
Install lock washers in the annular grooves of axle 18.
Install spring 5 together with hinge 6 on axle 17, and lock washers in the annular grooves of the axle.
In the same way, install and secure the rest of the release levers and thrust ring springs. Install and fasten the thrust ring 7 with hinges 6.
Install the assembled pressure plate on tool 16 or a flywheel with an insert that provides an installation dimension "A" equal to 29 ± 0.1 mm.
Install washers 11 together with heat-insulating pads 13 and pressure springs 9 on the bosses of the pressure plate.
If the working surface of the pressure plate was subjected to grinding, then to save the total force of the pressure springs, place metal washers under the thermal insulation pads.
The thickness of the washers should be equal to the thickness of the metal removed during the grinding process.
Install the clutch cover onto the pressure springs. Ensure the vertical position of the forks of 15 release levers and compress the springs using a press.
Fix the clutch cover with bolts. As a means to ensure the vertical position of the forks of the release levers, tubes installed through the holes of the clutch housing on the threaded ends of the forks can be used.
Tighten the nuts 3 and use them to adjust the position of the thrust ring 7 of the release levers.
After completing the adjustment, install the (pre-straightened) lock washers 19. Install the support plates 1, plates 4 and fix them with bolts 2.
Bend the ends of the locking plates on the verge of the mounting bolts. Bend lock washers 19 through the holes of plates 4 and 1.
In the threaded holes of the bosses of the pressure plate, screw four coupling bolts 8. Unscrew the bolts securing the clutch casing and remove the pressure plate assembly with the casing from the tool.
Mounting the clutch on the engine
Before installing the clutch, put 15 g of lubricant 158 into the cavity of the rear end of the crankshaft (under the front bearing of the gearbox input shaft).
With a clean cloth slightly dampened with gasoline, wipe the friction surfaces of the flywheel, middle drive and pressure plates.
Install the driven disc in the flywheel to 3 (see fig. 1) so that the longer part of the disc hub is directed towards the engine.
Apply Litol-24 lubricant to the friction surfaces of the squeezing levers of the middle drive disc 2 and insert the disc into the flywheel. In this case, the spikes of the disc must enter the grooves of the flywheel.
When you press the disc, it should move easily in the grooves of the flywheel and return to its original position under the action of the release levers.
Install the second driven disk 3 with the long part of the disk hub away from the engine.
Center the driven disks relative to the axis of the engine crankshaft using a splined mandrel, inserting its end into the hole in the front bearing of the gearbox input shaft.
Install the pressure plate assembly with the cover and secure the clutch cover with bolts. After securing the casing, unscrew the four tie bolts.
Install and secure the gearbox.
Check the quality of mounting the clutch and gearbox on a running engine at a crankshaft speed of 1800-2000 rpm, checking:
- - lack of jamming of the parts of the mechanism (drive) of the clutch;
- - the cleanliness of the clutch disengagement when the pedal is fully depressed. In this position of the clutch pedal, the inclusion of I gear and reverse gear should be carried out without grinding, and when the gear is on IV, there should be no rotation of the secondary shaft.
Adjustment of full and free travel of the clutch pedal. The full stroke of the pedal 2 (Fig. 3), which should be 195 mm, is regulated using the limiter 12.
To adjust the free play of the clutch pedal, disconnect the rod 17 from the lever 19. Loosen the lock nut of the link fork.
By turning the fork in the required direction, change the length of the rod 17 to increase or decrease the gap between the ends of the thrust ring and the clutch release clutch bearing.
Connect the rod to the lever 19 and check the free play of the clutch pedal. If it corresponds to 30-40 mm, tighten the fork locknut.
It is allowed to rearrange the lever 19 by one spline of the shaft (relative to the b marks located on the ends of the shaft and the lever), if the thread of the rod 17 is fully used during adjustment.
We also look at the article "Clutch of a KamAZ car", since the clutch is basically the same.