Not a good weekend for the cart need help

[hawgsalot]

I've got a 2004 48v precedent, batteries good voltage good, stock controller upgraded motor not sure the brand.

Over the weekend noticed a very small rear end leak, filled it up with fluid and figured I need seal kit. Played golf after it was full and I've never had a rear end roar or any noise coming out of the rear end. At the end of the round all of a sudden I'm getting a power up then hard motor power loss, let off the pedal power up and power loss. Goes down hill fine again no rear end noise so in my mind the seal leak and power issue is two different things but need your help and thoughts to trouble shoot. Thanks,