car-rut, rumbling of a cart
輘 centers on the deep track left by a cart wheel and the heavy, rumbling sound it makes while moving. Both meanings connect to the forceful passage of a cart.
輘 combines 車 (cart, vehicle) with 夌, which likely contributes the sound and may suggest a sense of rising or crossing over, fitting the image of a cart making deep ruts and rumbling along.
A cart (車) rolling over the ground leaves a deep track, and the right side 夌 looks like a series of rising and falling marks, like the ruts and the rumbling sound they produce.
For リョウ, imagine a cart rumbling so loudly it echoes like a lion's roar: lion -> リョウ, and the cart's rumbling is as deep and powerful as that sound.