Wildwood rear brake caliper centering

[HotWheelsKid]

I have the Wilwood 140-7146 rear brake set.
I am trying to center the caliper onto the rotor. I am unsure of what is acceptable or unacceptable with regards to just how centered the caliper is.

Here is where I am at right now.
I am using a small metal scale to measure the distance from the side of the rotor to the inside wall of the caliper.
https://thefactoryfiveforum.com/attachment.php?attachmentid=166574&d=1652239941


“Is the rotor in or out?” I believe the rotor on the passenger side is in. I believe I need to move the caliper more to the outside/farther away from the center of the car/axle/driveshaft. I currently do not any shims installed between the caliper bracket and caliper, but it seems like if I had one more I could remove, It would be perfect.
Outside rotor to side of caliper is just under 0.1", and inside rotor to side of caliper is just over 0.1"
https://thefactoryfiveforum.com/attachment.php?attachmentid=166581&d=1652240022
https://thefactoryfiveforum.com/attachment.php?attachmentid=166580&d=1652239984

I believe the driver side rotor is well centered. I used one shim between the caliper bracket and the caliper.
Outside rotor to side of caliper is just at 0.1", and inside rotor to side of caliper is at 0.1"
https://thefactoryfiveforum.com/attachment.php?attachmentid=166578&d=1652239984
https://thefactoryfiveforum.com/attachment.php?attachmentid=166579&d=1652239984

Can this bracket spacer on the passenger side, between the caliper bracket and the wilwood back plate be surfaced to remove material and help center the rotor? Or, is the passenger side caliper centering acceptable?
https://thefactoryfiveforum.com/attachment.php?attachmentid=166576&d=1652239984
https://thefactoryfiveforum.com/attachment.php?attachmentid=166577&d=1652239984

[HotWheelsKid]

Here are some additional wide shots
This is the passenger side, which I feel like the rotor needs to move left/out more.
https://thefactoryfiveforum.com/attachment.php?attachmentid=166583&d=1652241148

This is the drivers side which is pretty well centered.
https://thefactoryfiveforum.com/attachment.php?attachmentid=166582&d=1652241148

[Gordon Levy]

That is an inherent issue with the mosier rear end. Their axles tend to be 1/8" too long or longer than a standard fox 29" length. I don't know why but they are. The way to address it with that brake kit is to pull that block shim and mill it down or replace it with individual shims under each of the bolts. You won't be giving up any strength, it's a rotational load. The other thing to make sure is that you have absolutely no in and out axle play. What a fixed caliper brake setup it will cause knock back. Feel free to call me if you want to talk about setting up that kit. I have sold and set up thousands of them.

[HotWheelsKid]

Thank you sir. Exactly the information I needed!

[HotWheelsKid]

That is an inherent issue with the mosier rear end.

Well, you nailed it. Just removed and measured the axle, 29.125"


The other thing to make sure is that you have absolutely no in and out axle play.
I'm measuring about 0.07" in in/out play on the axle.
https://thefactoryfiveforum.com/attachment.php?attachmentid=166603&d=1652279110
https://thefactoryfiveforum.com/attachment.php?attachmentid=166602&d=1652279110

[Gordon Levy]

You can try it but i usually shim to 0 or even a little preload. As the posi wears the axle play will increase. Just something you need to be aware of.

[HotWheelsKid]

You can try it but i usually shim to 0 or even a little preload. As the posi wears the axle play will increase. Just something you need to be aware of.

I will go for zero, and will call to discuss next steps. thanks!

[J R Jones]

IMO clearance is the caliper issue. It is bolted and maybe shimmed to have clearance inside and outside. The pistons and pads find the rotor from there and self-adjust for wear which can be uneven.
The initial deviation which looked like 0.020-0.040 looked acceptible to me.
Sliding caliper clearance is also not critical, but the mount bracket straddling the rotor is.
jim

[HotWheelsKid]

Thanks Gordon Levy!


With his advice, I machined the Wilwood mounting bracket spacer to 0.400" and we sitting right in the middle of the rotor now!

https://thefactoryfiveforum.com/attachment.php?attachmentid=166872&d=1652734165

[HotWheelsKid]

You can try it but i usually shim to 0 or even a little preload. As the posi wears the axle play will increase. Just something you need to be aware of.

Thank you again Gordon!

I used your recommended alternating stacking method for the Shim/Friction/Steel in the drive gears of the rear end. Worked like a charm! Absolutely ZERO endplay!

I was too excited to get it together and forgot to take a picture of the alternating method, but here's a shot of the factory method before disassembly.

https://thefactoryfiveforum.com/attachment.php?attachmentid=166873&d=1652734427

I was super hesitant to crack that brand new trac-Lok open, the whole time I'm imagining Johnny 5 "no disassemble!". Gordon had absolutely no responsibility to help me out with this issue as I didn't even purchase any parts from him. But he did me a solid and he's reputation is spot on!

https://thefactoryfiveforum.com/attachment.php?attachmentid=166874&d=1652734659