Well, as luck would have it, one of my rear driveshaft u-joints decided to crap out while I'm on a trip about three hours from home... For peace of mind, I'd like to replace it before heading back tomorrow, but do I need a vise to do this? I seem to remember reading some other posts about guys changing them on the trail or roadside. What's the deal? I have the sockets to pound out and recieve the caps, as well as a big hammer. Will that do on the ground somehow?? Thanks in advance.