Thank you Will. 
Here are the three scholars' descriptions of what Rawat wanted to do as he grew older -
1. not allow others to dictate the direction and management of the movement.(Geaves)
2. manifest his own vision of development and growth. (Downton)
3. decide what direction the movement should take.(Melton)

and this desire caused

1. a deep rift in Prem Rawat’s family.(Geaves)
2. he had to encroach on his mother's territory and, given the fact that she was accustomed to having control, a fight was inevitable.(Downton)
3. a split between Maharaji and his family, ostensibly caused by his mother's inability to accept Maharaji's marriage to an American follower(Melton)

So how about "As Rawat turned 16, his desire to decide to dictate the direction of the movement led to split with his mother. His marriage to an American follower in 1974 caused a permanent rift and his eldest brother gained control of Indian DLM in a lawsuit whilst Rawat retained control of Western DLM.