U-joint adapters let you stick sockets in places you woudn’t imagine they’d ever fit. For example, I once saw Sean plug together four extensions and two u-joint adapters to reach the top bolts on a GM transmission bell-housing. But with ass-saving capability comes damn-why-won’t-this-stay-where-I-put-it frustration: Most u-joint adapters flop around, making it difficult to maneuver the socket into place.
GearWrench thinks they’ve solved the problem by installing a small internal spring that lets the u-joint move, but holds it in place when you let it go — so you can bend your crazy extension-tree into place then jockey it into the abyss right onto the nut.
They’re including the spring u-joints in seven of their various kits, and they sell ’em separately as well in a three-piece set containing 1/4″, 3/8″, and 1/2″ sizes. Street pricing for the three-piece kit starts around $33 and you’ll pay about $16 for individual adapters.