Checking the output flange on the rear transfer box

WARNING: This page is about a different car, the 2025 BMW M4, 2024 BMW M4, 2023 BMW M4, 2022 BMW M4, and 2021 BMW M4. However, it is still accessible from the selected car via links, so may be relevant.

Preliminary work

Refer to DISCONNECTING ALL BATTERY GROUND LEADS .
Refer to REMOVING THE CONNECTING SUPPORT FROM THE TUNNEL .
Refer to REMOVING EXHAUST SYSTEM .
Refer to REMOVING THE TANK COVER .
Refer to REMOVING THE LEFT THRUST FIELD .
Refer to REMOVING THE REAR HEAT SHIELD .
Refer to REMOVING FRONT HEAT SHIELD .
Refer to REMOVING TRANSMISSION CROSS-MEMBER .
Refer to PARTIALLY LOOSENING THE PROP SHAFT .
Refer to REMOVING THE RADIAL SHAFT SEAL FOR THE OUTPUT FLANGE .

NOTE: RISK OF DAMAGE
Damage to the transmission.
Damage to the transmission due to unapproved transmission oil.

Use only the approved transmission oil.
Check the transmission oil level after completing the repair.

NOTE: TECHNICAL INFORMATION
Always replace the output flange with a new radial shaft seal.

Determine the thickness of the new shim before the installation of the output flange.
Determine and note dimension (A) of the old and new output flange.

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Determine and note dimension (B) of the old and new output flange.

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Determine the dimension (C) (= thickness of the shim) of the old shim.

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Calculate thickness of new shim:
- Step 1: (Dimension A. (previous output flange) + Dimension C. (previous shim) - dimension B (previous output flange)
- Step 2: Dimension A. (new output flange) - dimension B. (new output flange
- Step 3: Result step 1 - result step 2

Follow-up work

Refer to INSTALLING THE RADIAL SHAFT SEAL FOR THE OUTPUT FLANGE .
Refer to FASTENING THE PROP SHAFT (PARTIALLY REMOVED) .
Refer to INSTALLING TRANSMISSION CROSS MEMBER .
Refer to INSTALLING FRONT HEAT SHIELD .
Refer to INSTALLING THE REAR HEAT SHIELD .
Refer to INSTALLING THE LEFT THRUST FIELD .
Refer to INSTALLING TANK COVER .
Refer to INSTALLING EXHAUST SYSTEM .
Refer to INSTALLING THE CONNECTING SUPPORTS ON THE TUNNEL .
Refer to CONNECTING ALL BATTERY GROUND LEADS .