Shower diverter adjustment
	
	
		Let me start by saying I an a renter suffering from half-assed maintenance.  
They recently installed a shower diverter, but it requires an awful lot of water pressure in order to stay "open".  As a result we are running out of hot water without being able to get through 2 short showers in the morning.  With the water turned on hard, I can feel the diverter catch when I pull it open, but with less water it doesn't catch.  
I have taken off the knob and the chrome tube covering the brass fitting itself, but don't see anything that can be obviously adjusted.  I don't know for sure the make, but the hot and cold knobs are from Kohler.  
Anyone have any idea?  Thanks.