Drive shaft failure.

[Ziegelsteinfaust]

I was driving my K20 to get pizza, and my DS failed. My truck is stock height with a stock DS. With 2.5 inches of compression on the slip joint available.

So as I went through a dip about 15 mph, and about 150 feet later my truck went pop.

I found a few pieces of broken cap on the street.

The U joints were on the frame I got the DS from, and all I did was grease them up with the install. When I inspected the DS I found plenty of grease in there.

So what should I look for as a failure point to prevent another tow home.

[NEWFISHER]

U joints fail. Maybe it was time?

[crossfire84]

The answer can be that the u-joint series is too small for the application. Or possibly you are using an inexpensive parts store u-joint that does not offer strength. Maybe you are using a greaseable u-joint and it is breaking across the grease fitting hole. The corresponding yoke is damaged or distorted and causing premature failure.

[Ziegelsteinfaust]

The DS was greaseable u-joint from the project frame I got, and likely what was installed in 1979. If a aftermarket u joint was used it would of been in the late 80's before it was parked from a tree hitting the cab, and parked. I do not see evidence of the u joint being anything but old though, and used. The cap that failed was broken in pieces, and I do not see damage on the + piece. I only quickly inspected as it was getting dark.

I will pull it off in a few hours when the chores are finished up. Of course it could of been the sound of 260HP 350 crate motor with bolt-ons that scared it to death.