Pre-tensioning the timing chain with the special tool

• Ensure that the timing chain is correctly  pre-tensioned with the special tool 2 455 654 .

  The pin (1) must close flush  with the housing (2).

  Courtesy of BMW OF NORTH AMERICA, INC.

• Ensure that the timing chain does not have too low  of a pre-tension.

  The pre-tension is too low if the pin (1) of the special tool 2 455 654 does not close flush with the housing (2).

  The timing chain is not pre-tensioned correctly. 

  Courtesy of BMW OF NORTH AMERICA, INC.

• Ensure that the timing chain does not have too high  a pre-tension.

The pre-tension is too high if the pin (1) of the special tool 2 455 654 does not close flush with the housing (2).

The timing chain is not positioned correctly. 

Courtesy of BMW OF NORTH AMERICA, INC.