It is necessary to regularly add grease to the axles and replace it as indicated in the grease chart

Pour oil into the crankcases of all vehicle axles through the filler (inspection) hole located in the upper wall of the gearbox housing, closed with plug 29, until oil leaks from the open control hole.

It is possible to add oil to the front axle housing, except for the filler hole, through the control hole located in the axle housing cover.

Maintenance of MAZ bridges

Check the oil level in the rear and middle axles during operation using a special level indicator 1 (Fig. 1) available in the tool kit.

To check the oil level in the rear and middle axles, unscrew the bolt indicated in fig. 1, fasten the gearbox to the axle housing and insert the oil level indicator into the bolt hole until it stops against the flange of the gearbox housing.

The correct oil level is marked with a mark on the oil dipstick.

When the oil level drops below the mark, it is necessary to add oil to the crankcase to the level of the control plug.

To release used oil from the front axle housing, there is a drain hole 48 (Figure 2) located in the lower part of the axle housing.

Drain holes for the crankcases of the rear and middle axles are located at the bottom of the crankcase covers.

In addition, there are additional drain holes for removing oil residues from the gearbox housings: a hole with a plug 30 (Figure 3) located in the lower wall of the front axle gearbox housing, and holes with plugs 36 (Figure 4) made in the front walls gear housings of the rear and middle axles.

Picture 4

Drain the used oil after preheating the unit through all available drain holes.

The control holes must be open.

If necessary, add grease to the steering knuckle housing for the bearings of the kingpins and the front drive axle pivot.

It is necessary to fill the grease in a heated state through the grease fittings 17 (Figure 5) located in the upper lining of the right steering knuckle housing and in the swing arm mounted on the left steering knuckle housing; you need to fill it until the grease starts to come out through the control hole located at the bottom of the ball joint.

Picture 5

Plug 27, which closes this hole, must first be turned inside out.

When changing the lubricant, all parts of the steering knuckle and the axle shaft joint must be washed.

Fresh grease is placed directly inside the ball joint, in the kingpin bearings and in the axle shaft joint.

The wheel hub must also be washed when changing.

When adding fresh grease, thoroughly lubricate the bearings.

Torques for bolted connections in kgm

Nuts for the bolts of the differential cups and the driven spur gear 12-14

Nuts for the studs of the differential bearing caps 17-19

Studs for securing differential bearing caps (when installed in the gearbox housing) 22—25

Bolts for securing the gear roller bearing caps - 6—8

Bolts for fastening the gearbox to the axle housing - 9—11

Nuts for fastening the semi-axes of the rear and middle axles of the flanges of the semi-axes of the front drive axle to the wheel hubs 7—9

Nuts for the studs for fastening the steering knuckle lever to the body and studs for fastening the ball joint to the front axle housing ... 16—18

Nuts for front, rear and middle trunnion fastening studs backbone 5.5—6

Nuts for fastening the flanges of the drive bevel gear shaft 20-25

Spur gear shaft bearing nut 35-40

Locknut for fastening wheel bearings 12-15

Tie rod ball stud fastening nut 23-27

Bridge breathers should be cleaned regularly.

Breathers for communicating the internal cavity of the axle housing with the atmosphere are located in the upper walls of the axle beams: on the front axle - to the left (along the way) of the gearbox, on the rear and middle axles to the right (along the way) of the gearbox.

Picture 6

In addition, there are additional breathers 19 (see Figure 6) for air outlet in case of failure of the head seals 22 for air supply to the wheel tires.

These breathers are located: on the front axle in the steering knuckle housings, above the steering link arms, on the rear and middle axles - in the end flanges of the axle housings.

The appearance of grease from the holes of these breathers indicates an air leak from the tire pressure control system.

The cause of the leak must be found and fixed. In case of leakage, it is necessary to replace the air supply heads to the tires.

It is necessary to check the absence of oil leakage through the glands and flange connections.

Faulty glands and gaskets must be replaced, and the bolts and nuts of flange connections must be tightened in a timely manner.

It is necessary to constantly monitor the tightening of the bolted connections, especially the gearbox mounting bolts, the nuts for securing the axle shafts to the wheel hubs, the nuts for attaching the ball joint to the flange of the axle housing and the nuts for attaching the steering knuckle lever.

It must be remembered that two of the twelve gearbox mounting bolts are located inside the gearbox housing. In order to tighten them, you must first remove the cover 26 of the gearbox housing.

Tighten the trunnion nuts each time the brake drums are removed.

When assembling bridges, the following requirements must be met to ensure tightness when a car overcomes fords:

  • 1) all flange connections, both with and without gaskets, must be lubricated with sealing paste during assembly;
  • 2) steel shims must be washed and lubricated with spindle oil (GOST 1642-50) or other similar liquid oil before being replaced;
  • 3) thin shims must be installed on both sides of the shim set;
  • 4) the control plug 27 of the drain hole (see Figure 5) of the ball joint must be lubricated with UN-25 brand paste before installation.

It is necessary to remove and insert the axle shafts very carefully so as not to damage the sealing glands and rubber seals of the air supply head to the wheel, located inside the trunnions.

Before installing the axle shafts of the rear and middle axles, the journals of the axle shafts under the oil seals and under the air supply heads must be lubricated with the grease indicated in the grease chart for wheel bearings. The thickness of the lubricant layer is 1-1.5 mm.

At the axle shafts of the front drive axle, the necks for the oil seals should be lubricated.

Before installing the front drive axle steering knuckle trunnions and the rear and middle axle crankcase trunnions, the working surfaces of the seals and the surfaces of the centering holes of the air supply heads should be lubricated with a thin layer of the same lubricant.

The inside of the air inlet head must be filled with grease; at the same time, the hole for the fitting must be free of grease.

For the front drive axle, in addition, the necks under the air supply head and under the bronze bushing at the knuckles of the axle shafts must be lubricated.

The inner cavity "a" (see figure) of the half shaft oil seals and the space "b" between the air supply head and the support ring must also be filled with grease.

For the rear and middle axles, the following must be filled with the specified grease: space "a" (see Figure 6) between the air supply head and the protective sleeve of the stuffing box, space "b" between the axle shaft seal and the bearing side of the crankcase, and also the cavity "c » between the flanges of the trunnion and the axle housing.

When installing the trunnions in place, it is necessary to ensure the correct position of the air supply holes in the necks of the trunnions.

The hole should be facing:

  • a) for the front axle - up and back, behind the second pin for attaching the trunnion from the vertical;
  • b) for the middle bridge - up and back, behind the first pin from the vertical;
  • c) for the rear axle - up and forward, behind the first pin from the vertical.

Assembly and disassembly of the hinges of the front axle shafts The blowing axle is made with some effort when installing and removing the drive ball and requires a special skill, so the hinge should be disassembled only when absolutely necessary and this should be done in the workshop.

When disassembling, you should mark with chalk or paint the relative position of the drive and driven forks and drive balls, and when assembling, install all the parts in the same relative position that they had before disassembly.

To facilitate the removal of the semi-axes of the rear and middle axles and the removal of the flange of the knuckle of the hinge of the semi-axle of the front drive axle, there are bolt-pullers wrapped in the flanges of the semi-axes and locked with lock nuts.

For the same purpose, threaded holes M12 (pitch 1.75 mm) are made in the flanges of the following parts: steering knuckle pin; ball joint of the steering knuckle; trunnion beams of the rear and middle axles; a glass of bearings of the leading bevel gear of the reducer; bearing seat of the driven bevel gear of the reducer.

As a puller for these parts, you can use any mounting bolt with M12 thread (pitch 1.75 mm) used for fastening parts of bridges.

Removal of the upper kingpin bearing cover mounted on the steering knuckle housing is facilitated by tapping it with a hammer on the side, on the rough surface.