Launch Shudder, Already Dropped Carrier Bearing

Hello Everyone,

I have a 21 TRD Pro which is completely stock aside from some Pro Form 1.5” lift shackles in the rear. After I put the shackles on I had some noticeable shudder from the rear under mid or heavy throttle from a stop. I ordered a coachbuilder carrier bearing drop kit. It’s the 0-2” kit. After installing it the shudder is about 75% better, but still there. I then tried adding washers to increase the drop, this only made it gradually worse. Then I tried going down to three washers and slowly adding back up to the original thickness of coachbuilder spacer. Still with no luck. It was worse with just three washers. Any idea what else I could try? Thanks!