OOps, my bad, 1/2" socket fits tighter. 13 MM was rounding the head too much. Got new bolts and will check out if I still have shudder later today.

Ok, wheel bearing replaced but still shudder. Doesn't seem like a real bad shudder. I can let go of the wheel. Will now see if R1 Concepts will replace. Have already sent several e-mails but no reply. Will call them on Monday. Anyone know what is the acceptable amount of runout?

also,,,, make sure you install the wheels with a torque wrench and not just impact them on

I've done the torque wrench thing and found that my impact setting matches very well the correct torque setting. But double checking with a torque wrench is always recommended.

I have heard that your rotors can warped if the wheels are not torqued correctly and I also read that sometimes a hub that has too much run out can cause the rotors to warp.

Did you verify that the lower balljoint had play or not? you stated that you had play at 12-6

R1 Concepts is shipping me a new set of front rotors. For me that is a sign of a good company. They stand behind their product. Will tear it down this weekend and inspect some items again.

I'm hoping this will solve the problem but I have to wonder if there is something else that is out of spec that causes rotors to warp. I've always had problems with this car and have read a lot of posts on this site about shudder. Perhaps calipers? I have two new hubs. Or perhaps when rotating and balancing tires they apply uneven torque?

Calipers won't cause shudder unless they aren't bolted down tightly.

Let us know how those rotors work out, and if those fix your shudder problem.

Have you had your axles inspected? I suspect that mine on my Bonneville are bad as I had all of the other suspension components inspected and I'm still having a vibration at higher speeds.

Very true. My old rotors were perfect until the day I cross-threaded a couple of lug nuts. After that… well, there'* a reason why I only have one rotor and one set of pads in my spare parts box.

EDIT: I'm now watching this thread, as I upgraded to R1 slotted rotors.

I've had the R1 rotors, drilled and slotted, on the Bonneville GXP for 40k miles now, and I've always torqued everything down perfectly and had the wheel hubs replaced when they went. I am very curious to see how this turns out.

Got the new rotors on today. Examining the old parts the Left driver side has more wear than the right passenger side, about .025" Rotors don't seem to have much wear .1mm or so. Pads seemed about half worn. Pins were a little sticky so I greased them up until the would go in and out freely. Will test the rotors later today/tonight.