No way does a M12 bolt qualify as "thin." Unless you are working on a locomotive.

the book is not wrong you just looked in the wrong place! i did the same thing and broke mine off. its in part B of the engine chapter.

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84 300sd 2.47 dif 360k
26 mpg needs lots of love
given to me in pitty

89 civic hatchback auto 140k
33mpgs soon to be low to mid 40's
been in the family since mile 1

85 300d with unknown knock. driven over 30k with knock and still going. sold for $800