Exploding ball joint!

[SUBBYRU89]

Thank goodness you ducked when you did.

Seems this is not a freaky Tom thing as I had thought...

"Acetylene Torch & Exploding Ball Joint
2002 F250 SD 4X4 CC

My son and his friend were changing the driver's side ball joints on my truck today. The castle nut on the upper joint was hard to remove, and the ball joint's shaft began to spin with the nut. ViceGrips, etc did not work, so he used the torch to cut through the shaft, just below the threaded area.

It cut though easy enough. The rubber boot (he assumes) was burning and he extinguished it. He removed the knuckle from the truck and laid it down next to him. Approximately two minutes later .... super loud boom. The remaining part of the ball joint's shaft exploded out of the joint's body, punched through the wood overhead door about 20 feet away, and lodged deeply into the garage's block wall. My son's friend saw the knuckle jump about a foot off of the ground as it happened. Both boys ears' were ringing from the blast (even though they were outside in the driveway).

The knuckle was sitting on the ground between them, as they were kneeling down working on the truck. If that steel projectile would have hit one of the boys in the leg ....... or in the chest ....... or in the head ........

I was in the house at the time. I heard the blast .... thinking that maybe the oxygen tank exploded or something. I said .... Oh My God. Then I heard the boys laughing, and I said .... Thank you God.

I'm only writing this as a friendly precaution to everyone. The ball joints were original .... therefore sealed (no grease fitting). But when things are "sealed," like joints, roller/thrust bearings, etc .... it is done with hard rubber (I think). But, someway, somehow .... the ball joint became so tightly sealed, and I assume the internal grease was cooking from the heat and producing gas/pressure, and it turned into a potentially tragic accident. I would have never thought it."

[svxistentialist]

Tom

I'm glad you were out of the firing line and you were OK.

Melis, is that account of yours from another forum? The rationale of gas buildup seems to be a good one. I would doubt if it is only pressure buildup from heated air or gas inside the joint. To my mind the amount of trapped gas within the joint should not have enough energy to deploy so much mass at force. I'm thinking it may be that the heat ignites the rubber and/or grease and this causes a fast release of gas propellant, rather like a bullet cartridge.

For safety sake maybe clamp a heavy vise or something on the outer end?

Joe