Bob's Resource Website

Disk Brake Stoneguards

If you look at any modern disk brake application, you cannot see the inside face of the rotor from underneath the car. They are protected by disk rotor guards, which are stamped circular sheet metal plates bolted between the spindle and the rotor. The guards should NOT be taken lightly and were provided by the factory for of a number of good reasons
  • A) protect the rotor from debris flying around between the wheels while you're cruising down the road.
  • B) keep water splash from 'lubricating' the rotors when you may need them the most. The outer part of the rotor is protected by the rotating action of the rim.
  • C) The inside center of the guard fits over the inner wheel bearing hub and seal and has a sluice, which will redirect any leaking grease onto the outside of the guard, instead of your rotor, which would severely negate any braking action.

The refitting of the shields is not rocket science and takes just a little bit of tweaking. You'll be surprised at the outcome.

No where in the installation instructions for the front disk brake kit were the rotor guards mentioned. They didn't fit the install as the new calipers are on the opposite side of the rotor. Thus, many of us have removed and discarded them. In the case of the rear, there weren't disk brakes to begin with and no provision made for adding them.

It was decided to retro-fit the stone guards in the front and fabricate new ones for the rear. It takes a bit more than just reversing them and bolting them on, however..

Also, see
Reworking the rotor guards
to fit the Turner Kit

(Jan 2008 - GT Hawk)

for an updated pictoral


The profile of the Turner caliper was just a bit larger than the original so a small piece of the guard had to be Removed and an additional hole drilled.

The guards bolted right back on in Reverse this way, BUT the new rotor is about 3 times as thick as the original and the inside area where the rotor vents start will contact and rub on the stone guard. So they required a little coaxing to get them to flare out and clear the inner rotor vent edge. I used the time tested technique called 'panel beating' ( ball peen hammer, lead dolly, patience and a light touch) to accomplish this and now they fit without any clearance problems.

The result is a very professional looking install.

Here's the outside passenger side and the inside driver side

REAR: The rear had to get the same treatment. These were much easier and were cut from 3/32" flat aluminum stock using the front guards as a pattern. The rear guard thickness also was adequate enough to replace the 'backing plate spacer' that was supplied with the rear disk kit. This only applied to one side tho because removing both would require the collar that adjusts the endplay to be screwed in too far, making the adjustment impossible. I wound up with a spacer and a stone guard on the driver side and just the stone guard on the passenger side. After some cutting and filing, the guards looked fairly decent and I have peace of mind now that all the rotors are protected.

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These pages and programming contained therin are © 1996 - , Bob Johnstone and may not be reproduced without the permission of Bob Johnstone All Rights Reserved.
Some technical opinions are my own from experience, other informational data is from online sources with credits when available and while care has been taken to be as accurate as possible, it is offered only as a guide and caution should be exercised in the application of it.