I got ours from Rock Auto, but I don't know if they still carry them. I think NAPA also has, or can get, them.
I did a little surfing to learn more on runout. This link brought out the potential in indexing the rotors to minimize hub/rotor runout. I copied a particularly useful discussion below the link.
https://g35driver.com/forums/brakes...rotor-shims-what-they-how-do-they-work-3.html
Sorry for reviving such a relatively old post, but I would like to contribute from my own experience.
- Instead of turning rotors when you get a vibration from rotor runout, indexing the rotors to a position of minimal runout can temporarily reduce or eliminate the brake vibration for another thousands of miles before you turn them. Let's say, my existing rotors now have 10,000 miles on them and runout has gotten to 0.007", causing a very slight vibration. I would index them and achieve back to 0.0015". Yes, I REALLY did that, from ~0.007" to 0.0015" on my G35 on BOTH front rotors. I saved $40 on resurfacing and extracted another 10,000 miles out of them before they had to be resurfaced. This prolonged the life of my rotors because I did not shave any metal out of it, I restored trueness by simiply rotating them!!!
- Rotors that are not perfectly true can work to your advantage if your hubs have a slight runout. If your hubs have a little bit of runout from age and wear, a tiny amount of rotor runout will allow you to index them and balance out the runout on both items.
- The quality of the lathe can greatly determine your rotor runout. Many people incorrectly suspect that their hubs or rotors are junk because the shop that resurface the rotors have done such a poor job on them. Dirty or rusted mounting points, or even a piece of hair could have a profound effect on the trueness of the rotors!!! The diameter of a hair is approximately 0.004". If that is stuck on your rotor, then you MAY have that kind of runout.
- Clean not only the hubs and the back side of the rotors before mounting, but also the mounting surface of your wheels!!! You will notice smoother braking and smoother ride by cleaning the backside of the wheels during a brake job.
- When indexing rotors, tightening a couple of lug nuts or torquing all five to specification made no difference whatsoever. I did many experiments and found that there was no observable difference between torquing all five lugs or just tightening two. Even if there was a difference, it wasn't detectable by the typical dial gauge used for rotor indexing. Furthermore, the FSM only instructs to use two or more lugs when measuring rotor runout. Statistically speaking, whether you use all five lugs or just two, that woudn't change which position you use: you only have five positions to choose from (or four if you have 4 lug hubs).
- The FSM suggests a runout of 0.0014" for the G35 (0.0028" for most other Nissans such as the M45, Maxima, etc). This specification is for installing new rotors. As the rotors go through regular usage, they would NOT remain at 0.0014". However, you want to maintain runout to a minimum as you install new rotors, so that you will have more headroom before you experience vibrations from runout. As you use your brakes, runout develops from normal use. Typically, 0.005" of runout is still tolerable for used rotors and can still be used without having any other work performed as long as you are not getting vibration. If you measure excessive runout from your used rotors after 10,000 miles, don't panic, that is not an indication of underlying problems. It's just regular wear. Don't turn or change your rotors just yet, try indexing them to gain more life from them before turning or replacing your rotors. Save your time and money.
- Excessive runout doesn't always cause vibration. Sometimes excessive runout is experienced through uneven pad wear. On a S550 I worked on, the rotors had about 0.01" of runout, but no brake vibration whatsoever. Don't you wish all cars are like that?
- Some skeptics may argue that indexing used rotors is not a good practice because the FSM doesn't mention it anywhere. The FSM would NEVER advise technicians to index rotors to restore trueness. They advise the technician to turn them. This is because machine work translates to revenue for the dealer. Indexing rotors does not generate as much revenue. Many people, including myself, have saved a considerable amount of money just from indexing rotors at home.
Finally, indexing both new and used rotors depends on a lot of variables and requires a lot of luck. You can have brand new hubs and rotors and still not achieve rotor trueness. This is why manufacturers have on-car lathes to correct such phenomenon in the assembly lines.
