Product review (5 stars): LG Trom WM2677HSM - Door Boot Gasket Part # 4986ER0001C
My washer is a LG Tromm model no. WM2677HSM. The door gasket part number stamped on the original gasket is 4986ER0004 No. 2...I could not find this replacement part anywhere, and went with this one (4986ER0001C) as it was cross-referenced to the washer on various sites. This substitute part works fine except for one detail. There is a drain formed into the bottom of the gasket which does not apply to WM2677HSM... Warning: It must be plugged! One just needs to plug it either with silicone, or a small shut-off valve clamped to the one inch long drain.

If you are replacing the gasket and have found that your door hinge is stiff, and doesn't open and close like it used to, the door hinge is probably worn out or corroded and will also cause leaks, and the hinge springs probably have failed. That part number is LG...4775ER2002A. Don't replace it with a used one on Ebay, as it may be half worn out at best, or totally useless at worst.

Edit: If you're going to go through the trouble of replacing the boot gasket, consider replacing the door hinge, as they usually fail simultaneously. Otherwise, you may find yourself doing so a short time later. The hinge is a pressure zinc casting, and when mated to the steel front panel, the two dissimilar metals react as a battery and cause a electrochemical reaction which is known as galvanic corrosion. Eventually the hinge pin, and the mounting screws seize up, contributing further to the boot gasket leaking problem, as the door can longer fully close. It's $30 well-spent...