Roush UCA and NVH
I have a 2012 GT with Steeda sports amd Koni yellows, stock LCAs. I installed a Steeda adjustable UCA and HD mount to be able to adjust pinion angle. Part of the reason for choosing the Steeda was that they claim no increase in NVH. Despite their claim, I figured there would be some increase in NVH - it only seems to reasonable with the poly bushing.
The slight increase in road noise and small thumps over expansion joints and small bumps were aceptable to me. Despite several pinion angle adjustments, however, I still get what sounds like gear whine at about 40 to 50 mph and louder whine at 80 mph. It's too annoying for me and the wife.
I took the car to the dealer to have the rear end checked and took the technician with me on a demonstration drive. He heard the noise and agreed to check it out. The conclusion was that the rear end was fine and that the poly bushing on the UCA was transmitting vibration to the body. I trust the dealership and take them at their word.
I need to get rid of the noise but would still like to have a UCA that is a little better than the stock UCA. My questions are twofold: 1. change back to stock or try a roush UCA with their rubber bushing? 2. for owners with the Roush UCA, is it as quiet as the stock UCA?
Yes, the Steeda was installed and torqued properly.