Symphony of Sounds of the GT-R - Part #1 of 4

ANNOYING SOUND #1: CHING CHING CHING - SHAKING OF LOOSE CHANGE

This is the first sound that I observed on my GT-R very soon after I purchased it and drove me nuts. It seemed to be very prevalent when driving over a moderately bumpy road and most noticeable at lower speeds, due to reduced wind noise. Although my local GTR master technician tried very hard to fix it, there was no resolution from him or NNA. The important thing was that it was not a suspension component issue, thus I started to troubleshoot it myself.

Adding Cross Spring to Upper Pad Pin

To re-ceate this sound distinctly, here is what I recommend:

1. Find an empty back alley or the back of a wide building/warehouse along which you can drive as close to the wall and as safely as possible. The wall will help amplify the sounds. 
2. Put the windows down and drive ~5-10mph along the building, without pressing on the brakes as much as possible. To keep transmission shifting sounds to minimum, switch to Manual Mode, gear 2.
3. As you go over any bumps on the road, you will hear an amplified version of what you may have previously heard. Sounds like some loose change jingling in the wheel well. This sound will minimize, but not go away completely when the brakes are lightly applied.

This sound is caused by the upper Pad Pin rattling in the brake caliper assembly, and sound like this:

As you have observed, the upper pad pin does not have a Cross Spring Clip installed on it. This is apparently by design and normal as per Nissan. I cannot comment if other similar Brembo brake packages also use a single cross spring clip or not.

The resolution is rather simple.

1. Order Quantity 2 of Part # 41090-JF20C from your Nissan Dealership Parts department. It should cost ~$6.00 each.
2. Remove the front wheel.
3. Remove the upper pad pin by using a punch and a hammer. Place the punch on the outer side of the pad pin, hammer it back about an inch until the pin can simply side out from the back.
4. Install the new cross spring clip by first snapping it on the tie rod.
5. Insert the pad pin back from the inside of the caliper, through the new spring clip and to the outside of the caliper. Hammer the pin from the inside gently so that it is flush against the caliper and resembles bottom one or the picture below.
6. Repeat for other side.

Adding Cross Spring to Upper Pad Pin

There are two possible downsides to this modification/fix:

1. I have noticed that the brake pedal feel changes slightly, the initial brake pedal force that is required for the same amount of brake bite goes up slightly. This means that I have to press the brake pedal slightly harder for the same initial bite. The braking force or brake effectiveness does not change though. This means sense because the pads how have to overcome the force of 4 total cross springs rather than 2. If this is an issue, especially when going to the track, these can be simply removed before tracking.
2. Perhaps this affects brake cooling slightly since more area is covered now, but I have not been able to empirically prove or disprove that fact, so I am not worried about it.

On the positive, side, I have NOT noticed that pads wearing down unevenly due to the additional cross springs as I have been through 3 set of pads since installing additional cross spring clips and this specific noise has been eliminated completely. Also the second noise discussed next is reduced somewhat.