Product review (4 stars): Fixed our LG WM0523hW Washer In About 20 Minutes
Our LG washer began acting funny, making odd noises and eventually stopped spinning.  Being mechanically inclined but with ZERO experience with appliances, I took to the web to find out what was happening.  After some digging I found a nice video by an appliance store that walked through the very easy replacement process of this part.
I cross-referenced the part number, found it very cheap on Amazon with Prime Shipping and ordered it up for replacement 2 days later.  As another reviewer mentioned, the most difficult part of this job is pulling the washer out.  I left all the hoses hooked up but disconnected the power.  You will need an extra set of hands to have someone hold the drum from spinning while you loosen the main drum bolt.  Everything else spins off quickly and easily.  The stator (the big round thing with all the copper coils) has a bit of weight to it so you'll want to balance it on something while unplugging the connections from it.
The position sensor itself was far smaller than I thought it was going to be - maybe 3 inches long.  It comes off the stator easily with a quick pry from a flathead screwdriver.  The new one just snaps right on.  Tighten up all the bolts you took off in reverse order (getting a little help again to hold the drum while you tighten it up) and you're back in business!

A cheap $13.00 and seriously no more than 30 minutes of your time round trip and you'll be ready to wash your clothes again.  It's nice to find quick, easy and cheap fixes like this!