Any ideas how THIS could happen?
#11
03-19-2009, 11:42 PM
Breakage of studs is usually from excess movement, which is usually from looseness. Although those c15's have so much torque they might be flexing the block slightly. I know you can break brackets that way on some engines.
Studs will slowly stretch from heat cycles, creating looseness. Of course it might be impossible to tighten them after a while. 
#12
03-19-2009, 11:52 PM
Join Date: Feb 2007
Location: Somewhere North of 60
Posts: 887
I don't think the bolts are defective, just not strong enough.
They are hardened studs and nuts, best and strongest you can use, apparently they are just not strong enough, just like the exhaust manifold studs, strongest you can get in that size, but they break anyway. Exhaust studs won't cause anything to happen except a blown exhaust gasket, and they always break one at a time, there are 12, I usually wait till at least 4 maybe 5 break, then change them all, if you've never broke any its not IF they will break, just WHEN. Keep your eye on the exhaust manifold studs,although you WILL hear the leak. But I have had ALL of my exhust bolts changed, a couple broke around the time I took my truck in for the last factory warranty check up...I took it in for a total go over...just before the factory warranty came off...cause it's bumper to bumper. LOL they fixed ALOT of stuff! All minor, but broken bolts, that sort of thing.
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#13
03-19-2009, 11:54 PM
Join Date: Feb 2007
Location: Somewhere North of 60
Posts: 887
Breakage of studs is usually from excess movement, which is usually from looseness. Although those c15's have so much torque they might be flexing the block slightly. I know you can break brackets that way on some engines.
Studs will slowly stretch from heat cycles, creating looseness. Of course it might be impossible to tighten them after a while.
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Be the kind of woman that when your feet hit the floor each morning the devil says "oh crap, she's up!"
#14
03-20-2009, 12:06 AM
Breakage of studs is usually from excess movement, which is usually from looseness. Although those c15's have so much torque they might be flexing the block slightly. I know you can break brackets that way on some engines.
Studs will slowly stretch from heat cycles, creating looseness. Of course it might be impossible to tighten them after a while. Cat solved the block flexing by the steel spacers one under the head and one above the oil pan. The exhaust studs are definitly temp related, but not outside temp, just the manifold and turbo heat, those twin turbos put out some unreal heat, have you cooked the air cooler boots by the turbo yet? And yes, the manifold "moves" the studs are too small at 3/8" Cummins use 1/2" on theirs. The jake studs like you broke are also exposed to high torque from the jake, and are probably too small also.
#15
03-20-2009, 12:11 AM
Thing is the manifold needs to move. Not under the studs though.
If the manifold(all I've seen are 3 piece style) seizes together, you're going to have massive broken studs/bolts. |
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