Is a spindle knuckle and a steering knuckle the same thing

Hi, this is Bo, an auto expert on RepairPal's Car Genius team! Yes, in many cases, the terms "spindle knuckle" and "steering knuckle" can refer to the same component, especially in the context of a front suspension system. This part connects the wheel hub and the suspension components, allowing for steering and supporting the weight of the vehicle. For your 2005 Scion tC, if you're looking for a complete knuckle for the passenger side, you should be searching for a "steering knuckle" or "front knuckle." Just ensure that any part you consider is specifically designed for your vehicle’s make and model to avoid any compatibility issues. If you're unsure, it’s always a good idea to check with your mechanic or parts supplier to confirm you’re getting the right part. If you need any further advice or want help finding a trusted RepairPal shop in your area, please feel free to call us at 877-913-1554.