Connecting rod caps only have 36ft/lb torque, but not likely to come loose unless something else is wrong.
You can't(shouldn't) reuse connecting rod bolts and nuts from a connecting rod with a bad bearing, or broken connecting rod, they have often been stressed and could break.
Bearings are soft metal, oil is not used strictly for lubrication, its the cooling system for the bearings, if flow decreases bearings heat up and get too soft, that's what causes a bad bearing, the heat from less cooling.
And rod bearings especially because they absorb the explosive downward pressure when a cylinder fires, if rod bearing is hot and soft it flattens a bit because of the force..........
And you start to get the knocking noise because there is now a gap.
Crank bearings can be effected by low oil flow as well but they need to get very hot, at that temp the soft bearing metal starts to fuse with crank journal metal, like welding, then the bearing "spins" inside the cap, this blocks the oil holes so bearing gets even hotter, engine can grind to a halt at this point but one thing is for sure, once it is shut off and cools down the crank will be frozen, welded in place by the spun crank bearing.
Bearings like these do not spin, like some other bearings, these bearings are in a fixed position held in place by the connecting rod and cap, or the engine block and cap, this keeps the oil holes lined up all the time, the crank is the part that spins, and that area, between bearing and crank journal, is the part that heats up from friction.
Thats just FYI stuff.
Bearings can be looked at and cap reinstalled, they are not like a gasket that shouldn't be reused, a good bearing will last as long as a new bearing.
You just need to look at the bearing 1/2 that is in/on the cap, it will tell the story for the whole bearing.
Google: worn engine bearing images
Have a look at the differences, it will help you ID any issues
Last edited by RonD; 05-13-2016 at 07:42 PM.