4.3.1. Maintenance

Periodically check and at need adjust bearings of naves of wheels. Check existence of a gap in bearings rocking of the hung-out wheel. Pay special attention to correctness of adjustment of bearings of naves of wheels of the new car.
Periodically check and tighten fastenings of flanges of half shafts and couplings of shutdown of wheels.
Systematically change lubricant in naves of wheels according to tab. 1. For replacement of lubricant remove a nave from a pin, remove old lubricant and carefully wash out kerosene bearings and an internal cavity of a nave. The lubricant layer in a nave between bearings has to be 10-15 mm thick. Do not put in a nave lubricant more norm in order to avoid hit it in the wheel brake mechanism.
When washing and replacing lubricant do not remove a cuff in order to avoid its damage and violation of consolidation. Press off a cuff only at strong pollution of lubricant and replacement of hug bearings.
Periodically examine wheels and check an inhaling of nuts of fastening of wheels. The moment of an inhaling of nuts of 100-120 N · m (10–12 kgfs · м). For providing a uniform inhaling wrap nuts through one. For the prevention of jamming of nuts grease their each time at removal of a wheel. At detection of malfunction repair a wheel or replace.
Periodically check a condition of tires and pressure of air in them, on a measure of need rearrange tires and balance wheels with tires in collecting. Check pressure on cold tires. At need bring it to norm.
You watch that wear of a protector of tires did not exceed extreme size (to wear indicators).

Fig. 242. Scheme of shift of wheels


At uneven wear of a protector rearrange tires in the sequence shown in fig. 242.
Shift of tires has to be pobortovy: forward and back wheels on one board are interchanged the position. The spare wheel does not participate in the scheme of shift.
At intensive uneven wear of forward tires check and at need adjust a convergence of wheels which has to be 1,5–3 mm.
The order of adjustment is specified in the section "Peredny Bridge".
At emergence of "spotty" wear of tires or the increased vibration of a steering wheel check and at need carry out static or dynamic balancing of wheels with tires in collecting. Wheels it is recommended to balance for prevention along with shift of tires to prevent the increased wear of tires and details of steering.

Balancing of wheels with tires assembled
Before balancing the wheel needs to be cleared of dirt. For simplification of installation of a spring of a balancing small weight pressure in the tire is recommended to be reduced to 50 kPa (0,5 kgfs/cm2).
The wheel imbalance in collecting with the tire should not be more than 1600 · cm (40 g on a wheel otbortovka from each party).
Dynamic balancing of wheels is carried out on the special machine.
At lack of an opportunity to carry out full dynamic balancing it is possible to execute static balancing on the adaptation imitating rotation of a wheel on a nave and providing the greatest ease of rotation.
Wheels are balanced by means of the special small weights and springs established on an otbortovka.
Balancing on adaptation is carried out the next way:
1. Bring a wheel into rotation. After a stop of a wheel put with chalk a tag on its top "easy" part.
2. Repeat operation, rotating a wheel in the return direction, and put the second tag on the top part.
3. Halve distance between tags and make the third (average) tag which will define the "easy" place of a wheel.
4. Establish one or several small weights near the third (average) tag for a full equilibration of a wheel. If the mass of small weights precisely does not manage to be picked up, then instead of originally established small weights on both sides from a tag put even number of in pairs identical small weights which total mass exceeds necessary a little, and then, moving apart them on equal distances from an "easy" point of a wheel, achieve position of stable equilibrium.
5. Divide whenever possible equally the picked-up small weights on weight and establish from both parties of a wheel opposite the friend's friend.

Adjustment of bearings of naves of wheels
Carry out adjustment of bearings carefully. At a weak inhaling of bearings in them in time of the movement there are blows destroying bearings. Besides, big gaps in naves of forward wheels increase the brake pedal course. At too hard inhaling there is a strong heating of bearings owing to what lubricant follows and bearings leave an operation.
You carry out adjustment of bearings in the following order:
1. Lift a jack a wheel which bearings need to be adjusted.

Fig. 240. Nave of a back wheel: 1 – wheel;
2 – nave bolt; 3 – nut of fastening of a wheel;
4 – adjusting nut; 5 – bolt of fastening of a half shaft; 6 – lock washer; 7 – lock-nut; 8 – persistent washer; 9 – half shaft; 10 – pin; 11 – laying; 12 – bearing; 13 – nave; 14 – persistent ring of the external bearing; 15 – brake drum; 16 – maslootrazhatel; 17 – laying of a maslootrazhatel; 18 – persistent washer; 19 – cuff; 20 – persistent ring of the internal bearing


2. Turn off bolts 5 (see fig. 240) fastenings and take out a half shaft of the 9th back bridge (or remove the coupling of shutdown of a wheel of the forward bridge). For removal of a half shaft wrap two bolts strippers in openings of its flange.
3. Unbend a mustache of a lock washer 6, turn off a lock-nut 7, remove a lock washer.
4. Turn off a nut 4 adjustments of bearings on 1/6–1/3 turns (1–2 sides).
5. Turning a hand a wheel, check ease of its rotation. In case of hard rotation eliminate the braking reason (for example, a drum zadevaniye for brake blocks, jamming of cuffs, etc.).

Fig. 243. Adjustment of wheel bearings: 1 – neck; 2 – a key for adjustment of bearings


6. Tighten a nut of adjustment of hug bearings by means of a key of 2 (fig. 243) and a neck 1 with a length of 300-
350 mm by effort of one hand before hard rotation of a wheel. When tightening a nut press a key neck smoothly, without breakthroughs and turn a wheel correctly to place rollers on running paths of rings of bearings.


Fig. 244. Latching of nuts of wheel bearings


7. Turn off a nut on 1/4–1/3 turns (1,5–2 sides), establish a lock washer 6 (see fig. 240). Tighten a lock-nut 7 and stop both nuts, bending washer moustaches on a side of a nut and a lock-nut (fig. 244).
8. Check adjustment of bearings after a lock-nut inhaling. At the correct adjustment the wheel has to rotate freely, without jammings, a noticeable axial gap and rolling.
9. Establish into place a half shaft of the back bridge (or the coupling of shutdown of wheels of the forward bridge), then bolts with spring washers and tighten them. Moment of an inhaling of 60-70 N · m (6–7 kgfs · м).
Check correctness of adjustment of bearings on heating of a nave of a wheel at the movement. If the nave heats up strongly, turn off a nut on 1/6 turns (1 side), observing the sequence and rules stated above.
When checking adjustment of bearings on heating of naves do not use working brake mechanisms as in this case naves heat up from brake drums (disks).
At emergence of cracks on a lock washer 6 replace it.