The transmission of torque to the drive axles is carried out by cardan shafts (Fig. 1) of an open type, each of which has a movable spline connection and two cardan joints

The design of the rear and front cardan shafts is the same.

Rear Cardan Shaft

Fig. 1. Rear driveshaft

They differ only in length, and also in that the rear cardan shafts have a thin-walled tube 13 (Fig. 1), while the front ones are made of a combination of a pipe and a shaft.

Splines of cardan shafts can be of two types - straight-sided or involute.

Maintenance

Periodically check the tightness of the bolts securing the flanges of the cardan shafts to the flanges of the transfer case and the drive gear of the final drive of the front and rear axles.

Check clearances at joints and splines, lubricate them according to the lubrication table.

Tighten the flange bolts to failure.

For lubrication, use a syringe with a special tip.

This tip fits over the syringe and is included with the driver's tool kit.

Excessive grease should not be injected into the splines, as it will be ejected from the spline connection, which will lead to premature failure of the glands and may knock out the sliding fork plug.

The cardan shafts do not require any adjustments.

Repair

The cardan shafts are dynamically balanced.

Remove the imbalance by welding the plates at the ends of the shaft.

In case of an individual repair method, install parts suitable for further work in their original places where they have run in.

Before removing such parts, mark them in any way that does not cause damage to them (paint, punching, etc.).

To repair, remove the shaft from the car.

Disassembly of the cardan shaft

Unscrew the clip 12 (see Fig. 1) of the stuffing box seal of the spline connection, having previously straightened it in the points of punching, and slide the seal towards the pipe.

Measuring the radial clearance of cardan shaft splines

Fig. 2. Measuring the radial clearance of the gimbal splines shaft

Measure the radial clearance of the cardan shaft splines (fig. 2) at a distance of 75–80 mm from the splined end of the fork in two perpendicular planes with an indicator and write down its value.

Disconnect the spline connection of the shaft, remove the rings 9 (see Fig. 1), 10, 11 and the clip 12.

Remove the circlips 2 with a screwdriver.

Using tool 71-2427, press the needle bearing cups out of the fork eyelets and disconnect the cardan forks.

Clean and wash all parts of the cardan shaft.

Assessment of the technical condition of cardan shaft parts

Measuring cardan shaft pipe runout

Fig. 3. Measuring the runout of the cardan shaft pipe

  • 1. Straighten or replace bent shaft. After straightening, the allowable runout of the shaft should be no more than 0.6 mm at any point along its length (Fig. 3). Straighten the shaft on prisms.
  • 2. Replace the D-pad if:
  • – stud diameter less than 16.26 mm;
  • - there are longitudinal dents on the spikes;
  • - the necks of the cross under the cuff are heavily worn.
  • 3. Replace the seals of the mechanical seals when their working edges are worn or damaged.
  • 4. Replace needle bearings if:
  • – bearings swing on spikes;
  • – one of the needles is lost or deformed.
  • 5. Replace the worn parts of the cardan shaft pin connection if the radial clearance in the splines exceeds 1.3–1.5 mm.
  • 6. Replace worn yokes if the bearing bore diameter is greater than 30.02 mm or the dimension between the fork lugs is greater than 60.1 mm.
  • 7. Replace the rubber or felt ring when worn or damaged.
  • 8. Replace the spline seal race if the internal threads of the race are stripped.
  • 9. In case of wear or breakage of individual parts of the shaft, replace the shaft if it is not possible to balance it.

It is allowed to replace a set of cross with bearings and seals as an assembly without balancing the shaft, if vibration does not appear.

Gimbal assembly

  • 1. Install the sleeve 12 (see Fig. 1), the felt ring 10, the rubber ring 11 and the rings 9 on the splined end of the cardan shaft.

Before Sat Lubricate the felt ring 10 with the spline tool and lubricate the splines.

  • 2. Assemble the spline connection so that the forks of the universal joints are in the same plane; deviation no more than 5°.

To do this, align the marks (arrows) made before disassembly.

  • 3. Screw clip 12 all the way and twist it in two opposite places so that the edge of the clip is slightly bent into the groove of the sliding fork.

Location of grease fittings when assembling the cardan shaft (view from the side of the bridge)

Fig. 4. Location of grease fittings when assembling the cardan shaft (view from the side of the bridge)

  • 4. Install the crosses and yokes of the joints so that the grease fittings of the spline connection and the cross located at the bridge are in the same plane and on the same side of the shaft, and the grease fitting of the cross of the opposite end of the shaft is 90 ° counterclockwise when viewed from the side of the bridge ( Fig. 4).
  • 5. Fix the fork with the cross in a fixture or vice and press the needle bearing cups into the lugs. At the same time, make sure that the working edge of the seals of the mechanical seals of the bearings does not wrap.

Install the retaining rings 2 in the grooves of the cups.

  • 6. Assemble the universal joint of the opposite end of the shaft in the above way.
  • 7. Lubricate the hinges with Litol-24 grease before assembling, for which fill each bearing with grease to 1/2 of its volume.
  • 8. After build check:
  • - ease of movement of the hinge forks.

The forks must move (without sticking) by hand;

  • - the value of the angular displacement in the hinges of the assembled cardan shaft.

The amount of angular movement for one hinge must not exceed 0.3 mm (nominal value 0.23 mm) at a radius of 35 mm under the influence of a torque of 98-117 Nm (10-12 kgf m).

When replacing flanges or forks, balance the assembled shaft dynamically. Permissible imbalance after repair is no more than 26 gf cm.

Gimbal failures

Failure cause - Remedy

Propeller shaft vibration (manifested as a hum and intermittent noise that increases with vehicle speed)

Shaft out of balance - Balance the shaft. If this is not possible, then replace the shaft assembly with a hinge

Bent cardan shaft - Straighten or replace shaft

Great wear on the trunnions of the cross. Longitudinal dents on the trunnions - Replace the spider complete with bearings

High wear on spider needle bearings - Replace bearings

Great wear on propshaft spline - Replace shaft

Worn holes in the yoke ears and flanges of the cardan shafts - Replace the shaft, flanges or sliding yoke (in case of heavy wear of the holes in its ears)

Knocking or weak knocks in the driveline that appear when shifting gears or when the car coasts

Loosening the bolts securing the cardan shaft to the flanges of the transfer case and drive axles - Tighten the bolts

Wear of the splines of the flanges of the cardan shaft to the drive axles and transfer case - Replace the flanges

Great wear on propshaft spline - Replace shaft