11 28 020 Replacing tensioning device for alternator drive belt (N55)

2011 BMW 335is 2D Coupe, Automatic DCTSECTION 11 28 020 Replacing tensioning device for alternator drive belt (N55)

Special tools required: 

  • 11 0 390

Necessary preliminary tasks 

Drive belt route 

NOTE: Mark the direction of travel of the drive belt if it is to be reused.

Turn belt tensioner (1) towards the right until the bore hole (2) of the belt tensioner is flush with the bore hole of the crankcase.

Hold belt tensioner (1) under tension.

Secure belt tensioner with special tool 11 0 390.

Remove drive belt (3).

Fig 1: Drive Belt Routing Diagram
G09845196Courtesy of BMW OF NORTH AMERICA, INC.

Remove special tool 11 0 390.

Remove cover from deflecting element.

Release screw (1) on belt tensioner.

Tightening torque: 11 28 1AZ .

Fig 2: Identifying Belt Tensioner Screw
G09845197Courtesy of BMW OF NORTH AMERICA, INC.

Assemble engine.

RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • You smell fuel, burning insulation, or see smoke.
  • Brakes feel soft, pull hard to one side, or make grinding noises.
  • The engine overheats, stalls repeatedly, or misfires under load.
  • You are missing required tools, torque specs, or safe lifting equipment.
  • You are not confident in the next step or safety outcome.