I worked just down the hall from the engineers developing the 1994 7.3L PowerStroke diesel for Ford. One day I noticed a large metallic object one one the guys desks. As I approached his desk, I realized it was the end piece of a drive shaft with about 180° tWist in it !
As I stood there dumb struck he said, "This is what happens when you take an F350 dually, load it to the max, rec the engine to 2000 RPM and side step the clutch ! Something has to give !"
"We have exploded clutch, U-joints and broken or twisted axles. This was the first driveshaft we twisted !"
