Volume Calculations Off When Using Different Methods

using disk method and integrating for y

using shell method

So there was this question in openstax calculus where we needed to calculate the volume of a solid that is created by revolving the area between the lines y=3x, x=0 and x=3 around the y-axis. I got different results when using different methods. I think I made a mistake when setting up the integrals but couldn't figure where.