ok so heres the deal,
we are under there replacing the ball joints attempting to remove the hub/wheel from the truck. this is 2wd 97 so pretty simple (pressed in), only the hub is frozen to the ball joint after we loosen the nuts. lots of hammering and cursing and prying, no luck. out comes the propane torch and we cut the top joint in two between the upper a frame and the hub. we then try to do the same on the lower to completely free the hub/wheel. Just before the bottom joint is completely cut in-two, BOOM! a loud explosion as the hub lands on the floor.
only thing i could think of was the grease in the joint got hot enough to ignite and perhaps it was sealed good enough to explode rather than burst into flames. just curious if this was a common mistake made by EDIT like me who try this with a torch. Any body ever heard of this? Is my theory correct about grease exploding? luckily nobody or nothing was hurt or damaged in the proccess.

 

You should have rented or borrowd a ball joint press. It's like a big fat c clamp made special for removal and installation. Our Autozone will let you borrow tools for free if you buy the parts from them. It makes this task very easy.

 

The old plastic injected u-joints use to do that when you heat them up ...LOL ...
Like CharlieZ said ...Big C-clamp press is the trick .

Greg -

 

Just a guess but I think it was right to the edge of coming out and the contracting of the mount and the expanding of the joint (from heat) just pushed it over the edge. If it went bang and the thing just fell down I doubt it was serious. Shrapnel is serious
Grease doesn't explode without enough O2..Like LOX, what's inside a joint wouldn't be enough to make a pop.