7.3.1. Adjustment of bearings of naves of back wheels

It is necessary for adjustment of bearings:

Fig. 6.19. Back nave: 1 — an epiploon; 2 — a persistent washer; 3 — the internal bearing; 4 — the external bearing; 5 — an adjusting nut; 6 — a lock washer; 7 — a lock-nut; 8 — a half shaft; 9 — laying; 10 — a nave; 11 — the brake drum




• to lift wheels a jack so that tires did not concern the support plane. To turn off nuts and to take out a half shaft of 8 (fig. 6.19), to turn off a lock-nut 7, to remove a lock washer 6, having weakened a nut of the 5th fastening of bearings on 1/3 — 1/2 turns, to check ease of rotation of a wheel. In case of braking of a wheel to remove the cause of its hard rotation (a zadevaniye of a drum and brake shoes) and only after that to carry out adjustment;
• to tighten a nut of the 5th fastening of bearings a special key with a neck (600 mm) the moment from 70 to 100 N · m (7 — 10 kgfs · м). When tightening a nut it is necessary to turn wheels for uniform placement of rollers in bearings;
• to turn off a nut 5 on a corner 22 — 45 ° (on 1 — 2 cut, no more, on a lock washer 6). To establish a lock washer and to be convinced that the lock pin entered a washer cut;
• to tighten a lock-nut the 7th moment of 150 — 200 N · m (15 — 20 kgfs · l);
• to check adjustment. At the correct adjustment the wheel has to rotate freely, the axial side play should not be;
• to insert a half shaft 8, to put spring washers and to tighten nuts of hairpins of fastening of a half shaft. To lower a wheel;
• to check adjustment of bearings on extent of heating of a nave of a wheel at a control run of 8 — 10 km. Strong heating of a nave (over 70 °C, the hand does not suffer) is inadmissible and has to be eliminated with repeated adjustment.
Bearings of naves of back wheels are oiled, arriving from a case of the back bridge on casings of half shafts. Therefore after adjustment of bearings it is necessary to check oil level in a case of the back bridge and if necessary to add oil. For filling of a cavity of naves lubricant it is necessary to lift serially right and left wheels on height not less than 300 mm and to hold not less than 6 min. at a temperature of oil and air not less than 15 °C.
The sizes of the interfaced details of naves of back wheels are specified in tab. 6.2

Table 6.2. The sizes of the interfaced details of naves of back wheels, mm