Auxiliary belt replacement: BMW E70 B30A; F10, 31 drive (N55B30A)

Step-by-step auxiliary belt replacement for the BMW E70 B30A; F10, 31 drive (N55B30A): 10 steps. What to remove, in what order, and what to check after.

Workshop procedure for BMW — the exact step sequence and torque figures, straight from real workshop data.

10 steps 1 engine code

🧭 Before you start

Fits: platform codes 335I, -XDRIVE, |, 535I, XDRIVE, 35I

Timing position: the crankshaft or camshaft is set and locked during this job
Special tools named: locking pin, locking tool

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At removal, mark the direction of rotation; when refitting ensure the drive belt rotates in the same direction

🔧 Engine codes this applies to

N55B30A

📋 Procedure

Special tool:
Remove the fan cowling
Note: At removal, mark the direction of rotation; when refitting ensure the drive belt rotates in the same direction
Turn the tensioner pulley clockwise until the locking pin fits
Hold the tensioner pulley in position

N55B30A? Steps differ between engine variants — check this job against your exact car before you commit to it. Check my car — free →

Lock the tensioner; use a locking pin
Remove the ancillary drive belt
Refit the ancillary drive belt
Remove the tensioner locking tool
Refit the fan cowling

Other BMW procedures

Who makes these pages, and how

TorqFix was built by a mechanic — after a 2,700 km drive with five roadside repairs that no diagnostic tool could explain.

The figures on this page come from manufacturer workshop documentation and are shown as they are. The page is assembled automatically from that data — it is not written by an AI. The AI works in the chat, where it answers for your specific car. It writes nothing here.

Variants of the same model differ. Cross-check torque against the factory manual for your engine before final tightening.

Seen a figure that does not match your manual? Write to us — we correct it and note when. support@torqfix.com

The story behind TorqFix →

Workshop data on this page last updated 20 Sep 2026.