Fogging of the crankcase throat and even the formation of individual drops in an amount not exceeding the norm indicated below is not a sign of leakage. With abundant droplet release, determine the condition of the stuffing box.
Determining the state of the gland
1. Put the car on a lift or a viewing ditch.
2. Clean the breather from dirt, check its condition.
3. Having unscrewed the control plug, check the oil level in the axle housing; if necessary, top up the oil level.
4. Clean the neck of the gearbox housing from traces of oil and wipe dry.
5. Hang the rear axle and place it on stands.
6. Start the engine, engage direct gear and, at a speed of 90–100 km/h, warm up the oil to a temperature of 80–90°С (within approximately 15 minutes).
7. With direct gear engaged, at a speed of 100 km/h, determine the amount of oil flowing out in 15 minutes.
Oil leakage exceeding 5 drops in 15 minutes is a sign of seal failure.
A damaged oil seal can be replaced without removing the gearbox from the vehicle, unless other gearbox parts need to be replaced.
Oil seal replacement
1. Drain the oil from the rear axle housing.
2. Loosen the rear wheel mounting bolts; place stops under the front wheels and hang out the rear axle; release the parking brake and place the shift lever in neutral.
3. Remove wheels and brake drums.
4. Unscrew the nuts securing the brake shield to the axle beam and use the ejector to remove the axle shafts from the differential box.
5. Disconnect the propeller shaft from the drive gear flange and move the shaft to the side.
6. Check the moment of resistance to turning the drive gear with a dynamometer and note its value.
7. Holding the flange with a special wrench, unscrew the nut securing the drive gear flange and remove the flange with the washer.
8. Remove the drive gear seal.
9. Install without distortion, with a mandrel, a new oil seal, having previously lubricated its working surfaces with LITOL-24 grease.
Attention! In order not to damage the oil seal during pressing, it is necessary to press it not to the stop, but to a depth of 2 mm (tolerance «-0,3») between the end face of the gearbox housing and the outer surface of the stuffing box.
10. Install the flange with the washer on the drive gear and, holding it with a special wrench, tighten the flange fastening nut, periodically checking with a dynamometer the moment of resistance to turning the drive gear. If the initial torque was 58.8 Ncm (6 kgf cm) and above, then the new moment of resistance to rotation should be 9.8–19.6 N cm (1–2 kgf cm) more than the original. If the initial moment of resistance was less than 58.8 N cm (6 kgf cm), then tighten the flange fastening nut until a moment of resistance of 58.8–88.2 N cm is obtained (6–9 kgf cm). If, when tightening the nut, the moment of resistance to turning is exceeded, then disassemble the gearbox, replace the spacer sleeve with a new one, after which the gearbox is assembled and adjusted (see subsection 7.4.7.6).
Assemble the rear axle in the reverse order of disassembly.