i was replacing the rear shocks. old one came out, new one in, good so far. tighten the upper mounting nut to spec (63ft-lbs per bentley). all of a sudden the mounting bolt snaps! WTF! it's not even to spec yet.

fortunately the mounting bolt is a through one and i can get a replacement at the yard tomorrow...

weather,

This sounds like metal fatigue especially if the bolt snapped where the inside of the shock meets the body. In this configuration, the bolt is in double shear so that area work hardens over time (shock cycles) and becomes brittle.

Had the same thing happen while driving in a 70s Ford, front shock bolt sheared and made one heck of a dent in the hood.

I would recommend replacing not only the upper shock bolts but the lower ones that go through the trailing arms, they are subjected to the same forces plus more rust.

jorrell
--
92 245 291K miles, IPD'd to the hilt, 06 XC70, 00 Eclipse custom Turbo setup...currently taking names and kicking reputations!

What does the fracture surface look like? Rust? Was it cracked before?
Oval pattern perpendicular to direction of shock travel?
--
George Downs, Bartlesville, Heart of the USA!

the bolt is pristine underneath. no stretches no rust. that's what i can't figure out.

Cheap after market fake bolt? Yeah they are out there.

Bet you never guess where they come from..........


Regards,

Paul