From my previous post a while ago, I made my OEM shift knob solid by filling it with resin, this reduced a lot of the rattle I was experiencing... Friday night I put in a modified intake that has no resonators on it, my shifter seems to no longer rattle under acceleration at any RPM range.

This leads me to believe that this rattle is due to harmonic resonant frequencies since mine would only rattle between 4000 - 6000 rpm under certain loads. Brought me back to memories of my old mustang, it was the king of all my cars for rattling at certain frequencies coming from the exhaust and intake.

It could be a fluke of nature that both these items stopped my issue, however, still unacceptable that a manufacturer cant figure it out properly based on all these posts. It could also be that slight manufacturing variances within the min-max acceptable quality levels changes which car rattles and which does not.

I'm hoping that my next mod (read UEL header) will solve this. I have the same thoughts that this rattle is frequency dependent.

Certain rpm and load sets it off. Let's see.

Reviving a dead thread... but did the UEL header solve the problem?

Well harmonics do cause vibrations, but dampening the sound is not fixing anything.

The rattle is from loose parts or parts just not fitting together properly. It could even be a damaged part such as my case where my shifter was actually made with a defect.

Sorry for not updating the thread. I wonder if I responded somewhere else...?

So the TSB made things worse?

Sure did. They eventually replace the transmission and then they replaced the clutch assembly for a rattle there. It still rattles pretty badly.