Crossflow rocker post bolt snapped

[Martin v]

No 1 post bolt snapped, luckily at walking speed. No other visible damage, ran ok but noisy at top end. Easily replaced but any idea why it may have snapped, anything else I need to check.  It may have just worked loose through use as no obvious cause. 

Car has steel posts, regular tappets and steel shaft. 

 

[Martin v]

.. and what is the rocker bolt spec please? Length I know and assuming Grade 8 but what thread?

Thanks

[Bricol]

The markings on the bolt head, assuming standard hex-head bolts will tell you grade.  Unlikely to be metric markings (such as 8.8) as I think crossflow is old enough to be using UNC threads - which if your location is correct, are more easily available there than in the UK.  As for size, a quick measure across the outer diameter of the threads will tell you.

 

[OliverSedlacek]

Unusual failure, unless there was some other problem (like not torqued up properly). I'm assuming you will replace all four.

[Martin v]

No idea of the cause. Yes, four new and torqued correctly should do it. 

[Martin v]

Bolt out easy, touched with a drill thinking I'd need to use an extractor and it moved. Managed to get out by hand amazingly which may explain why it snapped as it was pretty loose.

I am replacing bolts with correct ARP's. Maybe overkill but no harm. Two Questions.

1. Loctite or not? If so which?

2. With steel posts would torque setting of 30 ft lbs seem right?

thanks in advance.