broken rocker bolt
09-10-2007, 04:17 PM
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broken rocker bolt anyone know what would cause a rocker bolt to snap in half while driving? car has 69,000 miles on it and they werent over tightened. the big mystery is where the other half go. it didnt fall out when i opened the valve cover.
09-10-2007, 07:17 PM
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thats what im saying i have NO idea on how or what path the broken end would find its way to the oil pan or where ever it is if its inside the motor
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09-10-2007, 07:22 PM
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Originally Posted by vettenuts
Do you have a photo of the broken end, it can help detect the failure mode (bending, tensile, etc.)? Improper preload can lead to bending, which could cause it to fail much like a bobby pin when you bend it back and forth.
improper preload now theres an idea thats may shead some light on the subject. before the stud bolt it was believed by David (mighty mouse) i may be experiancing some improper preload do to the length of my pushrods which was causing the tapping noise that started after i installed my cam. i changed my pushrods to 7.425 the day before my rocker stud snapped. and no i dont have a photo of the broken end thats one mystery im still trying to figure out where it went since i cant think of any way it could find its way inside the motor where people are suggesting it is.
09-10-2007, 08:28 PM
#9
One would think that if there was insufficient preload the installer would notice it when approaching zero lash. That's not likely in this case since the pushrods are longer than stock. Besides if one wasn't tight enough they would all be loose and that condition would surely have been caught during the torqueing sequence. I can see losing a valve retainer keeper in the head, but a rocker bolt. That's a stretch. It has to be in there somewhere. Clean your glasses and take another look.
09-10-2007, 09:19 PM
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what im saying is that could it be possible that before i changed the pushrods i had stock size 7.4's i wasnt getting proper preload and over time the rocker stud just got weak from stress and snapped? and it just be weird luck that it breaks a day after me changing the pushrods
