I will tell you now to save you tons of time, and issues… Its important to assign your materials prior to mesh/combine. I name my materials. Not phong, or lambert. Select all mesh with object tool, and goto edit/delete all by type/history, and also non deformer history before exporting anything to unreal. Once thats out of the way. Drop down the file menu, and you should see " send to unreal. " Use the fbx format as listed, and your axis will be automatically corrected. Once in the engine simply click import. If youve never used this function before maya will have created a folder in your ue4 project titled import. Navingate to your unreal project and open the content folder. You should find your import folder, and fbx file. Simply select your fbx and your done.