2011 Yamaha F115 lower unit help

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I have a 20ft seafox and the previous owner had a 19p turning point prop. The the boat was not performing and took forever to get to plane.

Today I installed a new 4 blade 15p turning point prop. Right off the bat I notice a huge difference. Boat got to plane super easy and was hitting higher RPMs then i ever hit.

I was fishing the bay and went to put the motor in gear. Trying to speed up the motor was shaking like crazy. Anything over 6kts was very loud and lots of shaking. I cruised back to dock and noticed oil in the water. I raised up the motor and noticed gear oil dripping out.

Can anyone point me in the right direction? Was thinking my seals might have gone bad but this is the first time I've experienced anything like this.

Thanks in advance

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Easier to Drain, refill  while on motor. Put new  seals in.  Pressure test it.  If oil come out from upper side of lower unit you need to drop it. 


Pull it out of water . Make sure it's not motor oil drippin down. Once you know it the lower unit.  Pull it off the motor . 3 bolts each side (leave one bolt  barely threaded In to hold lower unit tell all bolt are out )15mm  maybe 14 ..  one under the black removable cap on top . Think 13 or 12 mm .tape it to your extension or  you will lose it. Leave bolt inside there no need to remove once lose. That drops anode  tab. One bolt under  anode tab I forgot size.   Now it will drop . Removing prop makes it's a lot lighter.



Asumming Hub kit was right for the  new prop you should have been ok. 


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