[Blue70SS]

Originally Posted by Stealth 2010 2SS/RS

The pfadt diff bushings are the street version.

Here's what I would do if it were my car

1st - Experiment with Pedder's street version of diff bushings. Obviously more work, but you can always sell them easily for 15 bucks or so less to another member if needed. If completely pulling the diff to do this, then I would inspect the inside - but I doubt you'll find anything, since the problem didn't show up till after the changes. It's nice to say I have a Pfadt car or Pedders car, but sometimes it's just what works the best. You might also try contacting Aaron Pfadt to see if they're experimenting with something different on the rear diff bushings. They do change things based on feedback. You might even mention the differences I noticed between brands of bushings.... he might experiment for you.

2nd - Try running 85w-140w rear diff fluid. Jannetty had mentioned to try this and helped some. I'm not sure if different brands work better, but heavier wieght makes sense - solely based on the colder diff seems to be quiter until the fluid gets warmed up and thinner.

3rd - Dynomat the trunk and below the rear seat. Might as well realize harder bushings are better for performance, but will transmit noises that were not noticeable beforehand. (not that they always transmit noise.... it has to be a "hidden" noise getting amplified)

Other things to consider.... outside temps. Minnesota is obviously colder right now, but your noise level comparisons should be done at roughly the same temps. Colder will be louder and suspension will be stiffer. So again, make sure you compare at same temps, same roads, and don't be fooled by the first few minutes of comparison on 1st drive of the day. I've notice rear end noise not being there at first, then once the rear is diff warmed up, noise comes back.

Hope this helps...