From Citroen SM Wiki

There are three chains in the engine:

  • One primary chain from a sprocket pressed onto the crankshaft to the intermediate shaft (jackshaft)
  • Two secondary (upper) chains from jackshaft to camshafts

Chain Dimensions

Chain Type

  • Both chains are 3/8 pitch double-row (ISO 06B-2) automotive quality.

Primary Chain

  • 74 links -> 29.750" long continuous.

Secondary Chain

  • 102 links -> 38.50" long with split link.
    • (each)


  • Renold
    • Formerly known as "BRAMPTON"
      • Chains marked this way are likely NOS and should not be fitted as they are early technology
    • "Synergy" is their state-of-the-art version chain (but is NOT) automotive quality.
      • It will serve if you are unable to find automotive quality.
  • "IWIS"
    • As used on 1991 Mercedes 420 SEL

  • Chains are still supplied by SM Club de France in the more recent but NOT latest technology.

See Also