I just got back from my Indie for an oil change, and got some advice on a vibration in my front end and wanted to run it by you folks here for input.
Since I got my new Michelin summer tires early last Spring, I had a vibration in my front end that start at over say 50 mph that smooths out around 95 MPH. I first noticed this with my new tires I had installed at the same time I took off my winter Pirellis (I hate them), so I immediately took them back to the tire shop and they re-balanced them telling me they were out (from two days before). The vibration was substantially lessened but I still have it even today. I know, I should have been more aggressive with them but I was stupidly busy at the time.
At the middle of last summer, my indy put the front tires on a balance machine and it came up zeroes. Today, he put them on a Hunter with road pressure and one wheel was 1/4 ounce off. This did smooth it out considerably despite being so little weight.
Now the mechanic really thinks the issue is the front control arms. I am not sure what you call these, but they are the fat arms that are lowest, and shoot out perpendicular to the car - not angled. He showed me the bushing on the inside part of the arm and he could put his screwdriver in between a sliver of rubber and the metal. He said this is normally bonded and if he can do this, there must be more wear inside where it counts. So... he thinks the vibration is from these arms and not the tires. I am not so sure but I can't argue with seeing the rubber delamination.
These arms are original on my 180K miles chassis. What do you think? The tires or the arms? If the arms, why didn't I notice it with my winter Pirellis? I just hate spending the big bucks to replace the arms and get a realignment if it is a defect in one of the tires.