Why are equatorial forests located only in the western part of the African mainland?

Wet equatorial forests are formed in places where precipitation falls evenly throughout the year. In such places of the planet, moisture enters in the form of both rains and fogs, which are brought by the wind from the side of the ocean. And in the eastern and central parts of the African continent, there is a fracture of the lithospheric plate, which is why chains of volcanic mountains have arisen on this territory, which block the path of moisture to the east. Precipitation falls on the western part, where equatorial forests have formed.