Busted rocker stud

[CowtownCobra]

Broke an exhaust rocker stud up at the start of the threads for the adjuster (hydraulic roller). At first glance nothing else seems wrong. Valve appears to be fully closed and not bent. Engine has about 14k miles on it. I just can't understand what would cause it to break. Might be a manufacturing flaw, or it might be ????

[bobcowan]

Check the others for signs of contact.

[playtimeover]

Hi bobcowan. What shall next thing to do after checking the other signs of contact? And if there is no other signs of contact, what shall do?

[Z-linkCobra]

Originally Posted by CowtownCobra

Broke an exhaust rocker stud up at the start of the threads for the adjuster (hydraulic roller). At first glance nothing else seems wrong. Valve appears to be fully closed and not bent. Engine has about 14k miles on it. I just can't understand what would cause it to break. Might be a manufacturing flaw, or it might be ????

So Im assuming the stud broke in between the adjuster and the rocker? Allowing the rocker to come off obviously. Does it look like it was broke off to one side or another...or does it look like it was pulled apart?

Check both contact points on the tip of the rocker, valve end as well as pushrod end. Any signs of damage?

Could be it was just a faulty stud. I cant imagine you having a clearance issue after 14,000 miles..but you never know.

[bobcowan]

Originally Posted by playtimeover

Hi bobcowan. What shall next thing to do after checking the other signs of contact? And if there is no other signs of contact, what shall do?

Then I would install a new set of rocker studs and drive on. KC has a reputation of using quality parts. But if one broke, I would be worried about the others every time I turned the key. Rocker studs are cheap, and the job is easy.

[Mark O'Neal]

Rocker studs whip like spaghetti.

Put a girdle on it.

[zrayr]

may be worth the expense of going to 7/16" studs and rockers. They are considerably more stiff than the 3/8" variety

Z.

[HeadDoctor]

2 Things are consistent here
1) Like mark said the the studs move around a lot - In fact the entire valve train looks like spaghetti when viewed on the stroboscope with engine running
2) It takes about 370 to 400 lbs of open pressure to control the valve train with a good hyd roller
3) Consider changing the studs to 7/16ths and putting a stud girdle on it you may have to get taller valve covers