I got the job done and the car runs fine. My mechanic said he has never seen a timing chain break in the 560 SELs but what usually happens is the plastic parts in the system get old and brittle and they do break...and drop into the chain/gear system and then all hell breaks loose. Valves hit the pistons, etc and you end up rebuilding the engine. He also said he has seen the chain break after the plastic gets in the links and the chain will blow right on thru the left valve cover. Spend the money now if you are over 100k miles and/or the car is over 10 years old.