jei_s2k

Rick,
It's based on wear of the axles. If the inside of the CV's are pitted or have wear from excessive bind or load, it will vibrate when the car is lowered. So generally a car with higher mileage(depends on how the car was driven in the past) will have a higher chance of the feeling such vibration after the car is lowered. When this happens, invest in axle spacers or get new axles.

Example:
1) brand new s2k's lowering job - no vibration issues, no spacers needed
2) well kept 70k mile s2k lowering job - no vibration issues
2) used s2k with 50k miles. It had signs pointing to heavy autox or track. Lowered the car, experienced heavy vibration. Wheel spacers solved the the problem.

chetly

I had the vibration, it was coming from the driver side cv cup. I run a heavy amount of autox and car is set up for that. It wasn't legal for the class that I run to install the spacers so I bought a new cup from majestic. Actually I bought 2 so if it happens again I don't have to wait 10 days and miss a event because of vibration. I also put in a higher quality grease than what comes with the cups.

Voodoo_S2K

This is important.

s4play

Thanks fellas for chiming in

Mac, yes I read that thread and a few others when I searched! The odd thing is I never noticed this vibration before until after I put in the new ACT clutch setup....?

My car just hit 15,000 miles and certainly never tracked or abused, rarely driven hard so I was surprised to find this problem. I just realized my rear tires seem a bit worn on the inside too so I plan to fix things systematically:

New Tires

Axle Spacers (Megan Racing)

Better Grease as Vu suggested


Just remembered I need a new battery too! grrr


thanks again fellas!

chetly

The vibration can start at anytime. I didn't feel it on the way to an autox but during the 2nd day it started. So as far as I can tell it's not something that gradually happens. It's almost instantaneous...