The gearbox of the MAZ-5335 car and its modifications during repair are disassembled in three stages: partial disassembly, general disassembly of units

For partial disassembly, perform the following operations

  • - The oil drain plugs are unscrewed, the bolts for fastening the intake cover 20 (Fig. 1) of the oil pump are removed from the gearbox assembly with the magnet, the gasket of the intake cover is also removed from the intake.
  • - Unscrew the nuts of the remote shift mechanism to the upper roof, remove the spring washers, the mechanism and the gasket of the remote shift mechanism from the studs.

MAZ gearbox disassembly

  • - Unscrew the bolts securing the top cover 13 to the crankcase 18 of the gearbox, remove the top cover assembly with the stem and forks and the cover gasket from the crankcase.
  • - Unscrew the bolts and remove the power take-off hatch covers and their gaskets.
  • - Unscrew the flange nut 16, having previously removed the cotter pin, remove the Belleville washer and remove the flange 16 (see Fig. 1) of the propeller shaft to the driven shaft of the gearbox with a puller (Fig. 2).

The bolts of the cover 15 of the rear bearing of the driven shaft are unscrewed, the cover with the oil seal and the speedometer drive is removed.

  • - Remove the clutch clutch spring 1, unscrew the nut that secures the hose for lubricating the bearing to the clutch housing 4, unscrew the hose assembly from the clutch clutch and remove the clutch assembly 1 with the bearing from the cover 3 of the rear bearing of the input shaft.</li >
  • - Unscrew the coupling bolt of the clutch release fork, remove the spring washer from it and, moving the shaft of the clutch release fork with the splined end forward, remove the fork.

Then, the key is knocked out of the groove of the shaft and the shaft is removed from the hole in the clutch housing 4.

During general disassembly, the following operations are performed

  • - Unscrew the bolts securing the cover 3 of the rear bearing of the drive shaft 2, remove the cover 3 assembly with the oil seal and remove the drive shaft 2 assembly from the gearbox housing 18, using a puller.
  • - Move the driven shaft 14 assembly forward until the rear bearing comes out of the socket, remove the retaining ring from the annular groove with flares and press the rear bearing and the worm 35 of the speedometer drive gear from the driven shaft with a puller.

After that, the gear box 18 is removed from the crankcase into the shaft 14 assembly and the first gear and reverse gears are removed from the splined surface.

  • - Unscrew the bolts securing the oil pump 25 to the gearbox housing, remove the pump 25 assembly and gaskets.
  • - Unscrew the bolts of the cover of the rear bearing of the intermediate shaft 17, remove the cover gasket. Remove the safety wire, two bolts securing the thrust washer of the rear bearing of the intermediate shaft 17 and remove the washer.

The axle 26 of the reverse gear block and the gear block 27 with bearings are taken out. Roller bearings and a spacer sleeve are removed from the block of 27 reverse gears.

The intermediate shaft 17 assembly is advanced until the intermediate shaft rear bearing exits the gearbox housing 18, the retaining ring is removed from the bearing groove with pliers, the bearing is pressed off the shaft and the intermediate shaft 17 assembly with gears is removed from the gearbox housing.

  • - Remove the splint wire, unscrew the bolts securing the clutch housing 4, remove the spring washers from the bolts and remove the clutch housing from the gearbox housing 18.

Then, the oil level control plug and oil channel plugs are unscrewed from the gearbox crankcase.

The final disassembly of the gearbox provides for the complete disassembly of the following components and mechanisms:

  • - driven shaft and rear bearing cap;
  • - intermediate and drive shafts;
  • - gearbox remote control mechanism;
  • - gearbox top cover;
  • - oil pump.

When disassembling the driven shaft and the rear bearing cover, perform the following operations.

Install the driven shaft 14 (see Fig. 1) complete with gears on the stand with the threaded end in a vertical position.

The spring thrust ring is removed from the annular groove, the front bearing, the synchronizer 5 of the fourth and fifth gears are removed from the shaft and the locking key is removed with the thrust washer of gear 8 of the fifth gear.

Insert a steel drift between the teeth of the internal gear of the fifth gear 8 and the thrust washer and, by rotating the gear, disengage the thrust washer from the splines of the output shaft.

Remove the 8th gear of the fifth gear of the driven shaft and the thrust washer of the fifth gear.

The gear 9 of the third gear and the synchronizer 10 of the second and third gears are removed from the shaft.

Gearbox puller

Having rested against the gear 11 of the second gear, they press the bushing of the gear 8 of the fifth gear, the bushing of the gear 9 of the third gear and the spacer bushing of the gears of the second 11 and third 9 gears on the press from the shaft.

The gear 11 of the second gear is removed from the driven shaft, the thrust washer of the gear of the second gear and the segment keys are knocked out of the grooves of the shaft.

After removing the splint wire, the bolts for fastening the replaceable gears are unscrewed from the cover 15 of the rear bearing of the driven shaft, remove the cover and cover gasket.

The cap of the interchangeable gear cover is unscrewed, the gasket is removed, the shaft of the driven spur gear of the speedometer drive is removed and the speedometer drive gear is removed from the cover.

Having installed the cover 15 on the stand with the plane of connection with the gearbox housing, the oil seal assembly is pressed out of it.

When disassembling the intermediate shaft, do the following:

  • - remove the thrust ring of the front bearing from the intermediate shaft 17, compress the front bearing and remove the thrust ring of the gear 24 of the intermediate shaft drive;
  • - pressed from the intermediate shaft in turn: gear 24, gear 23 of the power take-off drive, gear 22 of the fifth gear and gear 21 of the third gear.

In each case of pressing the gears, the keys are knocked out of the grooves of the intermediate shaft;

  • - remove the spacer sleeve, press the gear 19 of the second gear and knock out the segment key.

When disassembling the drive shaft 2, unscrew the ring nut, remove the retaining ring from the annular groove of the bearing with pliers and press the rear bearing with the puller, and then press the oil seal out of the cover 3.

When disassembling the gearbox remote control mechanism, perform the following operations.

Having fixed the mechanism in a vice, unscrew the bolts securing the crankcase cover 30 of the mechanism, remove the cover and gasket from the crankcase.

The lock washer is bent, the rod head bolt 28 is unscrewed, the rod and rod head are removed.

Disassembling the upper cover of the MAZ gearbox

The set screw is unscrewed, having previously removed the splint wire, the shaft 34 is pulled out of the mechanism housing 30, while simultaneously removing the gearshift lever 6 from it, and the segment key is knocked out of the groove on the shaft.

Having removed the splint wire, unscrew the set screw of the intermediate gearshift lever 29, remove the intermediate lever and knock out the segment key from the groove of the roller.

Unscrew the oil filler and oil drain plugs from the crankcase.

The locking screw with a washer is unscrewed from the crankcase 30 and the bushing, limiter pin 33 and limiter pin spring are removed from the crankcase.

Stem O-ring 2 is removed from crankcase seat 30

If necessary, remove technological plugs from the crankcase

When dismantling the top cover of the gearbox, do the following:

  • - the breather and oil filler plug 14 are unscrewed from the cover 13;
  • - turn out the glass 4 of the spring fuse for turning on the stroke together with the spring;
  • - unscrew the nut of axle 5 of leash 3, remove the spring washer, knock out axle 5, remove the leash from the axle and remove the pin of the gear lock from the crankcase;
  • - install the gearbox cover with the gearshift forks up;
  • - remove the plugs 1 of the rods, advance the rod 17 of the fork 20 of switching the third and fourth gears forward to the extreme position;
  • - unscrew the locking bolt 21, knock out the stem 17 from the fork 20 and remove it from the socket of the cover 13;
  • - unscrew the locking bolts from the reverse fork 15 and the stem head 2 and knock out the stem 12 from the fork 15, head 2 and cover sockets 13;
  • - unscrew the locking bolts of the fork 16 of switching the first and second gears and the head 8 of the stem, having previously removed the splint wire, and knock out the stem 8 from the fork 16 and the head
  • - remove the pin and balls 7 of the stem lock from the cover 13, having previously knocked out the plug 18, balls 9 and springs 10 of the locking rods of the gear shift forks.

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After disassembling, thoroughly rinse all gearbox parts in kerosene, blow with compressed air and inspect

Possible pump malfunctions may include: leakage of the diaphragm and valves, decreased elasticity or breakage of the diaphragm spring, wear of pump drive parts