Now that I had clearance for the spacer washers to sit, I had to figure out which thickness of spacers I needed to center the calipers. Others had posted using a fender washer on each bolt.
Yeah. That didn't work for me.
From Amazon, I purchased 3/8" ID x 1 1/2" OD stainless steel fender washers, that were listed as being 0.040" thick, as well as same size but 0.060" thick. This way I had some leeway for spacing. I was still under the impression I would only need one spacer per bolt. I drilled out a group of both thickness washers to 9/16" ID so the M14 caliper bolts would pass through.
Got a caliper mounted with a 0.060" spacer between the caliper and the spindle. Lightly torqued the bolts. And noticed immediately that the rotor was NOT centered in the caliper.
OK, take it back a part and rethink.
I measured each spacer washer with my calipers, and marked its size in Sharpie. So I knew what selection I had to work with.
I quickly realized I could not use my calipers to measure the gap between the rotor surfaces and the caliper pistons. Measuring point was too deep. Scratched my head for a bit. Until I remembered a little set of tools I bought years ago on a whim, and had never used. Snap gauges! Though finicky to use, they were perfect for measuring this gap.
Through several cycles of mounting, measuring gaps, demounting, repeating for each caliper, I ended up walking gaps into this:
Driver's upper outboard: 0.79"
Driver's upper inboard: 0.81"
This was using 0.063" and 0.061" thick spacers between the caliper and spindle.
Driver's lower outboard: 0.80"
Driver's lower inboard: 0.82"
This was using 0.065" and 0.061" thick spacers between the caliper and spindle.
Passenger's upper outboard: 0.80"
Passenger's upper inboard: 0.82"
This was using 0.063" and 0.055" thick spacers between the caliper and spindle.
Passenger's lower outboard: 0.80"
Passenger's lower inboard: 0.82"
This was using 0.063" and 0.055" thick spacers between the caliper and spindle.
I called 0.002" difference between outboard and inboard good and the rotor centered in the caliper.
Honestly, this is academic. I am using digital micrometers and snap gauges, and I don't do this for a living. There is most definitely some tolerance/error in my measurements. I was trying to get it as close as I could with what I had.
However...two things:
1) the brake pistons will 'self center' the pads on the rotor. A little misalignment will be OK
2) the numbers look good
![2024-02-15 019.JPG 2024-02-15 019.JPG](https://www.tahoeyukonforum.com/data/attachments/416/416853-69b399d069bf4b0e85be01a2c3788640.jpg)
Stainless steel fender washers used as spacers, shorthand marked with measured thickness. 58 = 0.058"
My digital micrometers are decent quality, and I am not a complete hamfist using them, but they are not lab grade. Good enough for what I am trying to do.
![2024-02-15 017.JPG 2024-02-15 017.JPG](https://www.tahoeyukonforum.com/data/attachments/416/416854-7f53d674262c24a610d2a6506ffd7ada.jpg)
The cutest little set of snap gauges. They were definitely the right tool for measuring the gap between the brake rotor surface and the caliper pistons.
![2024-02-15 021.JPG 2024-02-15 021.JPG](https://www.tahoeyukonforum.com/data/attachments/416/416855-914fb43d6bd3cb1f76c1ebce804b6882.jpg)
Top of driver's side caliper. Photo doesn't really show it, but the rotor looks centered in the caliper.
![2024-02-15 020.JPG 2024-02-15 020.JPG](https://www.tahoeyukonforum.com/data/attachments/416/416856-4475e478f5b240407efcbdaaed2b4801.jpg)
Bottom of driver's side caliper. Photo doesn't really show it, but the rotor looks centered in the caliper.