Cylinder head bolts with higher tensile strength - BT01.30-P-0003-01A

WARNING: This page does not describe the selected car, but rather 42 other vehicles, including the 1999 Mercedes-Benz S600, 1999 Mercedes-Benz S500, 1999 Mercedes-Benz S420, 1999 Mercedes-Benz S320, and 1999 Mercedes-Benz CL600. However, it is still accessible from the selected car via links, so may be relevant.

ENGINE 601.91, 602.91 up to 1.1.91, 602.96, 603.96 /97 up to 1.5.90

Modified cylinder head bolts have been installed in order to increase the pretensioning force of the cylinder head bolts.

The modified cylinder head bolts differ from the previous version in having a larger cylinder head contact surface and higher tensile strength.

Marking: code and ribs on bolt head.

Fig 1: Identifying Bolt Head Diameter

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Implementation of the cylinder head bolts with additional ribs as an identification were phased-in (2 ribs on bolt head, arrows).

Only the modified cylinder head bolts will be available as replacement parts. If it is necessary to replace one bolt on an engine with the previous cylinder head bolts, all of the cylinder head bolts should then be replaced in this case.

It is necessary to measure the length (L) each time before re-using the cylinder bolts, and to replace the bolts if necessary.

Fig 2: Identifying Cylinder Head Bolt Ribs

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.