Rosehill Performance Parts

Aluminum Register Centering Rings

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After completing a rear disk brake conversion like the Ultrastang Mark VII Conversion kit or several other aftermarket kits, there is a possibility of a "Less than ideal situation" that arises from using the Mark VII rotors or other Ford Rotors that have a larger center hole on the disk compared to the register hub on the axle of most stock Mustang axles. If you put on rear disks and bolt on the wheel and leave it on, it is not really a factor. But if you are the type that will be removing the rotors for other upgrades, measuring, test fitting other products or other reasons then it is possible that the rotor could be put back on and the pads not ride in the same wear area, losing maximum braking efficiency.

Most people doing conversions will need the rings if the Mk VII rear disc conversion is done on a stock vintage 8- or 9-inch rear end, because the hub in the center of the axle flange is smaller in diameter than the opening in the center of the Mk VII rotor.
If you have swapped a Granada/Monarch 9-inch drum brake rear end into your early Mustang and are doing the Mk VII conversion, then the rings would not be needed since these rear ends have the larger diameter center hubs that match the diameter of the Mk VII's rotors.

All Ultrastang Rear disk brake kits now come with the solution for this situation!!

The above photo depicts a rear disk brake on a mock up axle. There is a 0.34" gap between the disk and the axle hub. Even with the axle studs centering the disk, there is room for the disks to move around when the wheel is removed. Notice the gap around the wheel stud at the 9:00 position.

We have now started producing an aluminum spacer ring (With info. and assistance from valued Mark VII customers)

Here is a photo with the ring installed on the same mock-up.

This ring will ensure that the disks centers on the same wear pattern every time!!

These rings are CNC'd from high quality 6061 aluminum stock and will give you many years of Mustang service.

New and reproduction parts

If you need to order replacement reproduction parts for your Mustang make sure you check out Steve's Mustang Parts.

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