The other day I installed an authority short shifter into my evo IX, everthing went smooth with that. Yesterday I got around to sanding down the kartboy shifter base bushings and installing them. After I was done installing everything I double checked everything and made sure it was all put back together properly. I then went for a drive to check it out, I left the interior pieces out (the console pieces with the shifter boot and the cup holder) just incase i had to make any changes. As i started to drive I noticed and little bit of a rattle as I started in first gear and shifting into 2nd. I'm sure its there in 3,4,5 just cant hear it as well with engine rpm being higher. When in any gear and letting off the throttle the same noise is heard. So i parked at a car wash and gave it a slow rev with it in neutral and the clutch engaged, the noise started to be apparent at 2500 rpm. When the clutch is disengaged there is no noise what so ever just the engine rpm. I held the throttle down at about 2500 rpm and engaged and disengaged the clutch the sound it made while doing this did not sound good at all( a very pronounced rattle) I then re-installed the original shifter base bushings and took it for a drive with the same symptoms happening. I'm not too technical savy with engines but I'm thinking something with the clutch. I also did some reading around the forums and people with similar problems were getting responses about throw out bearings. I'm not sure if the installation of the short shifter and bushings could have cause this problem. I think I may have heard this noise before I ever installed the stuff. But it wasn't as appearent as it is now. If any body has some good sound technical help they can provide it would be very helpful thanks.