Here are your parts
Replacement parts for LG WM2277HB Washer | AppliancePartsPros.com
Here is a service manual just in case you do not have it.
http://appliancedigest.com/index.php...service-manual
You have to join the site to download the manual but it is free and this is a very good site for manuals and other info for the appliance repair DIYer.
It does sound like a pump problem to me.
I am assuming that you have already cleaned out the filter basket.
I had one a while ago that had what looked like orange algae growing in the drain hose. It had reduced the size of the drain tube considerably and I think this is what took out the pump. Took me a better part of an hour to get the drain tube clear of this gung.