Boogie Bar

This is just a guess, but I think this device is designed to hold the axle in place while working on either a U-Joint or an airbag. I am looking at that photo and see a lift (blue thing to right of the truck) so I suspect something is about to get lifted up. I am not a mechanic so I can't speak from knowing this. That phrase boogie or whatever is most likely a slang word much like the word stinger is used. I doubt you will ever find it online. I know there are people that visit these forums who can better answer that question.

 

This device is used to support the weight of the axle when the truck is being lifted by the frame or by one drive axle. It keeps the suspension from over extending and pulling the airbags and shocks apart.