Last month I bought an HFT 1/2 240 ft lb electric impact wrench for $38. Works great. At first I did not like it b/c I could not get a hub nut off then I remembered I put it on with a breaker bar with a pipe over the end that I then stood on, which I weigh 220lbs. They also have a battery powered version impact think is around 330 ft lbs.

1/2 in. Electric Impact Wrench

I use Ridgid because of the lifetime service agreement and performance. Here is my new 1/2" impact driver I got several months ago the day it released. Notice the 300 ft.-lbs of torque. It hasn't met a tight nut or bolt yet it couldn't handle with the 3 or 4 Amp/Hour batteries installed. a LOT OF BANG FOR THE BUCK! http://www.homedepot.com/p/RIDGID-1-...5yc1vZc88jZ18g