Did my 1998 M600 belts yesterday using the allen key method. Ended up setting them much slacker than last time when I used the twisting 45 degrees method! After 3 years the Exact belts that came off still looked basically mint, maybe a bit hardened.
I did manage to crack the "Horizontal rubber cap" a bit where the bolts go in. See pic below. Do I need to remove the cam gear to change this?