Clunky and rattling suspensions fix
After installing my Intrax springs in place of my ST springs two weeks ago, I was blessed with some rattling/buzzing and overall noise from my suspension over rutted and rough surfaces, They never made any noise over big bumps which led me to think it was something to do with the coil themselves. I was perplexed because I had installed everything correctly. Tonight while screwing around with my car (as usual), I jacked up the front end and inspected the front coils. Sure enough, it was very clear to me that the upper two coils were rubbing each other as observed by the worn paint on the coils. This makes complete sense to why I got noise over rough surfaces, but not on bumps. When the springs are only slightly compressed over rough surfaces they rub and rattle on each other, but on big bumps they are fully touching each other. I fixed this problem by cutting some clear vinyl tubing and placing it over the rubbing coils. I did the same in the rears. Sure enough on all the surfaces the springs moan/rattle/buzz were all gone. They were solid. No noises. The car also rode better which leads me to believe the coils were transmitting vibration. It was 40 degrees outside and the car felt solid. I am very happy.
Simply put, if you are going to use some of the lower springs available (Sprint/Intrax), it may be necessary to add spring isolators to the upper coils too.
I've got this done to rear springs as well. This tubing is available at any home improvement store. I used 1/2" clear vinyl tubing. You'll find it in the plumbing section. Cut the tubing in a spiral shape so that it stays on the spring. You don't have to remove the springs or anything.
What the supplies should look like: