He was spinning that thing to 7k and running above factory limits. Which is what the driveshaft was balanced for, stock, factory limits. It happens all the time

 

Lmao Did you consider that engine rpm's have nothing to do with driveshafts rotating speed. The 6900 is what it spiked to after it broke. Shift points are 6400

 

In 3rd gear the transmission gearing is 1:1. Im guessing his converter wasnt locked but we will say it was just for fun. The driveshaft was spinning..... 6938rpm

 

Reread what I posted.. That was not the rpm in which the driveshaft broke. That was fuel cut rpm. But I guess the factory driveshaft can't handle that and people like skeet who run stock driveshafts are on borrowed time, the fact of the truck bottoming out had no affect in breaking the ds?..

 

I had a 2000 RCSB and everytime i went over 100-110 it would vibrate like hell

 

All I saw was like five pictures posted with some words around them. "Where it broke" was in the middle of the output shaft picture and a picture of your laptop. So be more clear on which picture "where it was broke". PrtSC does print screen, instead of taking pictures of the screen.

Won't be able to tell one way or the other what caused, but ive seen the SAME twists in regular cab driveshafts and they never hit a bump. Ill stick to the idea that the factory driveshafts are not perfectly balanced from the factory, and so anything above the factory limits is on borrowed time unless re-balanced.

I heard that hours before I had a friends driveshaft blow up on me while I was driving behind them

 

Heck, with all that happening, where did the weeds grow out from?

 

Dude was lucky.. I've seen a dirt track car flip over front wards after dropping a driveshaft with no safety loop..

 

Hey brother! Good to see you over here!! How's NC been treatin ya?

Had to be something like that... there had to be damage done to it prior that compromised it's integrity. Good to see all are ok.

 

No one will know for sure what caused the failure... however, running lower rear end gears will certainly spin the driveshaft faster than before and I believe you hit critical speed of the shaft. Critical speed is the max speed a shaft can spin before becoming unstable.