[Chevy 350 Fan]

Ok I am no transmission expert but I was looking into a book I have on the th350. In there is a chart showing the mechanical power flow. In D1 it says it uses the forward clutches and the low roller clutch. In L1 it uses forward clutches the low roller clutch AND the low/reverse clutch. Here's where my lack of expertise may be showing. But I'm guessing normally in low, power is distributed between the low roller clutch and the low/reverse clutch. Assuming my roller clutch is the problem all the power goes to the low/reverse clutch. But since D1 doesn't utilize the low/reverse clutch I have no power to the wheels and it makes a whining noise. Is that perhaps the issue????????