@FastDriver
I appreciate the links. Next time I'll search more thoroughly before posting but the premise of the probability matrix I offered does have some value when it comes to evaluating your drive train odds of survival. Why was it so poorly received?
Not all u-joints are made of material so brittle that they fail without any evidence of the pending failure before it happens. I suggested this as a test of how much strain was being put on the drive train, not a recommendation of use so I don't understand the venom. You can only learn new things if you're willing to challenge what's accepted practice, it shouldn't be a reason to go off on somebody.
This is what I am thinking:
I'm thinking that in the 48 years you've been here on Earth, you've never, ever been to a drag strip.
You've never had a car that you beat on as a kid,....you've never done something stupid and heard the loud bang that comes as a direct result of the bad choice. You've never actually laid underneath one to see some puddle forming because fluid that was once contained in one of the drivetrain parts of that car, is now compromised, and pouring out of the hole or crack caused by your bad choice.
U joints come in two categories...stock, and heavy duty. Typically the stock one will/might have a grease fitting that compromises its structural integrity. It's made of low carbon steel and rated to withstand a significant amount of time and stress doing its job.
They wear out after doing their job for tens of thousands of miles...and ONLY after tens of thousand of miles.
When one breaks, it doesn't bend, twist, or stretch. It shatters or shears. It would never give you any visual clue as to its impending failure before that happens. You could be as diligent as you want, put the car up on a lift, inspect your stock joint, and give it your thumbs up.
Then go out, put a set of 8" drag slicks on the car, put it on a track, rev the engine to 5,000 rpm, sidestep the clutch, and
BAM!
No warning, no signs, no noise, no vibration before to warn you.........just one loud assed bang, followed by you laying on the ground looking at that stick thing that has now dug itself into the drag strip, and probably tore the hell out of the floor of the car at the same time.
There's no chart to gauge this,...and the probability factor is certain...it will break.
Either as a result of excessive force, repeated abuse, or stupidity...one, or a combination of all three will be the determining factor as to how soon.