ZF final drive units - Disassembling and reassembling the swivel housing

Remove the wheel hub. Remove pin (1). Unscrew nut (2) and extract the ball joint (3) from swivel housing (13).
Unscrew the nut and extract the ram ball joint.

Take out bolts (31) and take off the spindle (30). Remove the universal drive shaft (12). Take off grease nipples (22) (25) located on the upper and lower swivel pins (16). Take out bolts (21) (24). Remove arm (18) and the lower cover (23). With the assistance of another operator, hold the swivel housing.

Remove the swivel pins (16) from the housing (13) using an inertia extractor beginning with the lower swivel pin. If necessary, match shims (17) with their respective swivel pin.
Separate the bearing cones (4), deflectors (6) and O’rings (7) from the swivel pins. If needed, extract the bearing cups (5) inserted in axle housing (1) and match them with their respective cones (4).

 Clean and inspect the components. Replace any parts found to be defective.
Insert bearing cups (5) in the axle housing (1) using an appropriate fixture.
Assemble on each swivel pin (16):
- a new O’ring (7)
- a correctly positioned deflector (6)
- a bearing cone (4)
With the assistance of another operator, reinstall the swivel housing (13).
Position the pre-assembled upper swivel pin (16) in order to align swivel housing (13) and axle housing (1).

Replace the shim (17) removed during disassembly. Check for the presence of the Mecanindus pins (19) (20) and check that their slots are diametrically opposed. Install arm (18) by partially fixing it with two bolts (21).
Assemble the pre-assembled lower swivel pin (16). Place shim (17) removed during disassembly and Install cover (23). Assemble and tighten bolts (24) to a torque of 190 Nm.
Install all the bolts (21) and tighten to a torque of 190 Nm.
Turn swivel housing (13) several times from one stop to the other in order to seat the cones in their cups.
Using a torque wrench installed with a dial and an appropriate fixture that respects the axis of the swivel pins, check that the resistance of bearings (4) (5) is between 21 and 28 Nm. Otherwise, carry out adjustments.

- The adjustment principle consists of adding or removing shims (17) on the lower or upper swivel pins in order to obtain the previously stated bearing resistance.
Reinstall the universal drive shaft (12). Introduce a guide through the housing filler hole (1) in order to align the right-hand side transmission with the differential.
Install spindle (30). Lightly smear the threads of bolts (31) with Loctite 241 and tighten them to a torque of 295 Nm (Fig. 14).

Install the grease nipples. Using a grease gun, lubricate bearings (4) (5) on the upper and lower swivel pins. A 45º grease nipple is installed on the lower swivel pin.
Insert the steering ram ball joint and tighten the nut to a torque of 440 Nm.
Insert the ball joint of the steering rod and tighten the nut to a torque of 290 Nm. Lock it using a new pin. Install the wheel hub.
Adjust the steering lock stops. On the APL 5052 ZF front axle, the maximum allowed steering lock is 50º.
- The steering lock stops are located on the upper part of each swivel housing.

Replacing the seal and transmission Bushes

Extract the steering ball joints and the coupling bar.
If only the dust covers (10), seal (9) or bush (8) on axle housing (1) are to be replaced, integrally remove swivel housing (13) and the final drive unit.
- The removal of the lower and upper swivel pins is carried out in the same way as the disassembly of the swivel housing alone.
Using a suitable sling, hold and remove the entire drive unit assembly as well as the universal drive shaft.

Locate the position of dust covers (10) and seal (9) and drive them off the axle housing (1).
Carry out the same operation for bush (8).
Clean the components. Check that the seal and bush carriers are free of scratches and dents.
Lightly smear the rim of the bush with Loctite 620 or its equivalent and insert it into the axle housing using the service tool made up from drift, ref. 5870 058 026 and handle, ref. 5870 260 002 in accordance with the position marked during disassembly.
Insert the seal and the dust covers using a service tool made up from drift, ref. 5870 055 006 and handle, ref. 5870 260 002.
Lubricate the lip of the seal.
- For the replacement of the dust covers (27), seal (28) and bush (29) on spindle (30), in addition remove the planetary carrier and sun gear as well as the universal drive shaft.
- Then use the same method as described in operations 84 and 85 for disassembly and then operations for reassembly.
Install the entire final drive unit assembly using the same safety precautions taken during its removal.

Removing and install – disassembling and reassembling the universal drive shaft

To gain access to the universal drive shaft, it is necessary to:
- remove the upper and lower swivel pins and remove the housing assembled with the final drive unit.
- remove the planetary carrier and the sun gear.

Disassembling the seal of the universal drive shaft 

Hold the external section (12) of the universal drive shaft in a vice fitted with soft jaws. Remove the grease nipples and four circlips (3) at the ends of the universal joint. Using a soft hammer, drive the centre yoke (2) downwards until the bearing sleeve is visible.
Remove the opposite bearing sleeve in the same way and remove the protruding section of the shaft.
Turn the whole shaft through 90º, then repeat the operations to disengage the universal joint from the shaft.
Tighten the internal section of the universal drive shaft in the vice and repeat operations.

 Reassembling the universal drive shaft
Clean and inspect the components. Replace the entire universal joint including the spider, seals, bearings, sleeves and circlips.
Smear the needle bearings with bearing grease and ensure that they are all in the sleeves.
Position the universal joint in the yoke and push it as far as possible to one side so that the end of the spider serves as a guide for refitting the sleeve with the needle bearings. Push the sleeve deep into the yoke while holding the spider in order to Install the circlip.
Assemble the other sleeves and spider in the same way and Install the grease nipples. Using a grease gun, lubricate the spider.
Special point
- A 45º grease nipple is installed on the external spider.
Reinstall the universal drive shaft, carry out operation in reverse order.

Replacing a wheel stud

Chock the rear wheels. Apply the handbrake.
Lift the side concerned with a jack. Take off the front wheel and position an axle stand. Drive out the defective stud.
Install a new stud in the hub flange with its serrated area lightly smeared with Loctite 270. Reinstall the wheel and remove the axle stand and jack. Tighten the wheel nuts to a torque of 575 Nm.