31 21 180 Replacing bearings (wheel hub) for front wheel

WARNING: This page is about a different variant/trim than selected.

Necessary preliminary tasks:

Remove FRONT WHEEL

IMPORTANT: Expand turning lock sufficiently to avoid damaging thread when releasing collar nut.

Press brake pedal.

Unfasten collar nut (1).

Tightening torque 31 60 2AZ

Installation note:

Replace collar nut (1).

No oil permitted on thread of shaft journal or collar nut.

Secure collar nut on flattened area (2) of drive shaft by positive peening.

Fig 1: Identifying Collar Nut

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Remove BRAKE DISC .

Remove FRONT PULSE GENERATOR .

Release screws (1) and remove bearing from output shaft.

Tightening torque 31 21 1AZ

Installation note:

Replace microencapsulated screws.

Fig 2: Identifying Output Shaft Bearing Screws

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Use special tools (see BMW Workshop Catalogue).

Hydraulic unit - BMW part number 81 64 2 155 744
Adapter kit 1 - BMW part number 81 64 2 155 745
Adapter kit 2 - BMW part number 81 64 2 155 746
Adapter - BMW part number 81 64 2 318 661

The following operations describe the procedure for pulling the wheel bearing/wheel hub off the output shaft:

The following tools are required to pull the wheel bearing/wheel hub off the output shaft; see Fig 3 for arrangement:

Vehicle components:

I	Drive flange hub
II	Wheel carrier/swivel bearing

Required special tool components:

1	Hydraulic unit
E3	Washer M24
F3	Spindle M24 (length 270 mm)
C1	Holding sleeve
K2	Screws M14 x 1.5
B1	Adapter

Fig 3: Removing Output Shaft/Wheel Bearing

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Pull wheel bearing off the drive shaft using the hydraulic tool.

IMPORTANT: Secure wheel bearing with flange-mounted special tool to prevent it from falling.

Installation note:

Keep contact surface (2) of wheel bearing and swivel bearing clean and free from grease.

Fig 4: Identifying Contact Surface Of Wheel Bearing And Swivel Bearing And Threaded Holes

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The following operations describe the procedure for fitting the wheel bearing/wheel hub onto the output shaft:

The following tools are required to fit the wheel bearing/wheel hub onto the output shaft; see Fig 5 for arrangement:

Vehicle components:

I	Drive flange hub
II	Wheel carrier/swivel bearing
III	Output shaft

Required special tool components:

1	Hydraulic unit
E3	Holding sleeve M24
D1	Washer
F2	Spindle M24 / M20 (length 335 mm)
G4	Adapter M22 x 1.5 to M20

Fig 5: Identifying Required Components

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IMPORTANT:

Risk of damage!

The G4 special tool sleeve used has relatively thin walls due to its technical requirements. So that the load limits of the clamping sleeve are not exceeded when pulling in the output shaft, the adapter 81 64 2 318 661 must be used together with a torque wrench.

Fit adapter with torque wrench to hydraulic unit (see illustration).

Set torque wrench to 20 Nm.

Pull wheel bearing/wheel hub with hydraulic tool onto output shaft until the torque wrench is triggered.

Fig 6: Fitting Adapter And Torque Wrench To Hydraulic Unit

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