g16e wont go up hill

[wes5314]

I have 96 G16e when going up hill with 2 people on cart cart does not want to move but goes slow if i get off and help push on level ground it will fly with two people on it and in reverse it will back up normal batteries have 37.2 v all batteries have been loaded tested and are good when pressing the throttle on level ground motor makes a screech or a squeal like noise and will go away once going also this is a 36v electric motor any help would be greatly appreciated