I had one do that from Hurricane Ike. It's a red maple about 24" in diameter. After extensive research and consulting with an arborist here in Houston, I put two 3/4" threaded rods 90 degrees to each other thru the trunk and used 1/4" galvanized cable stretched between the major limbs, mounted with eye lag bolts and turnbuckles. The rods prevent further splitting, and the cables keep the tree from stretching apart in wind. After 5 years, my tree has almost absorbed the rods and the cables are still there doing their job. If you want to chat about it, my email is in my profile.