Conducting the Symphony of Sounds from GT-R


As most GT-R owners are aware by now, there is a complex symphony of sounds that is produced by the front of your GT-R in addition to the wonderful orchestra of the VR38DETT engine, and hopefully by now, joined by a non-stock mid-pipe and/or exhaust.

Over the years, I have researched, investigated, and tried to solve every one of the annoying sounds by removing them from the orchestra. Unfortunately, the typical response from Nissan North America has been that these sounds are part and parcel of the package, which I frankly refuse to live with, at least some of them. As more owners experience these annoying sounds, it makes sense to identify and solve each one with or without the help of the dealership.

Therefore, I am going to cover each type of sounds that comes from the front wheel area of the GT-R, how to distinguish each one, and if you are willing and able, show how to solve them permanently or at least for an extended period of time.

Warning, If you ruin something on your GT-R I cannot be held responsible for a duration of 100 years and on while on planet Earth.

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.

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.

ANNOYING SOUND #2: CLANK CLANK CLANK - LOOSE ITEMS IN THE TRUNK SOUND

This is the second sound that I observed after many months of ownership of the GT-R.  

To re-create this sound, repeat the same procedure as above at the back of building i.e. windows down, ~5-10mph in Manual Mode - Gear 2, except go over as many bumps as possible in a straight line this time around.

Now while going over the same bumps, apply slight brake pressure. With pressure to the brakes, you should notice that the clanking sound is completely eliminated while on the brakes. If you were listening for something else, repeat the procedure and identify the the sound that is eliminated by pressing the brakes. This is it.

The sound have just identified is the sound of the actual brake pads bouncing up and down in the calipers. This sound originates from both the front and the rear brake pads. It becomes more apparent with time as the brake pads are used and wear down since they now have slightly more room to bounce up and down in the caliper. Applying the brakes, presses the pads against the rotor and prevents them from clanking up and down.

There is simply permanent NO FIX for this. To slightly reduce the sounds, one can use two cross spring clips in the front, which does reduce the chatter. On the rear, the cross spring can be slightly bent to add more force to the pads, thus holding them tighter. I have done both of these and it lasts temporarily as the cross springs always revert back to their original shape after a few days as they are tempered..

Nothing should be done to modify the pads temselves, such as adding shims to any surface of the pads i.e. top, bottom or outer. Brakes are an important safety component should not be modified. Safety is more important than this noise, in my opinion.

Nissan has changed the rear cross springs across the various year models of the GT-R for a total of 3 different parts. The original USMY2009 and USMY2010 Model year had rear cross springs that applied lateral counter force to the pads against braking force in addition to the perpendicular force to "quieten" the pads. These were the quietest by far as they reduced the clacking sound the most. I had previously reshaped them to quieten the pads.

2009 Rear Cross Spring

2009 GTR Rear Caliper with Cross Spring
In later year models, the rear spring clips were modified to apply only perpendicular force to the pads and no lateral counter-force to braking as Nissan must have found that the rear original spring reduced rear effective braking force. Unfortunately, not only are the newer type of rear spring clips much harder to remove and install, they also considerably leave the rear pads to make the most amount of noise. The latest one ('13+) looks like the '11 but has a slightly different shape and are yet again even louder.

Rear  Brake Pad Cross Spring Comparisons

Even though I have a set of the original '09 spring clips, and '11 spring clips, I run the latest part number from the '13, as I would rather have more braking power and deal with the clank clank clank noise. One can successfully bend the fins of the cross springs slightly towards the pad to increase the force, this will stop the rattle but in my opinion will reduce the rear braking force.

For those that want to upgrade to the 2013 for additional braking but noisier setup the Nissan part number is 44090-JF20B and they run about $2.50 a piece.




ANNOYING SOUND #3: SQUEALING - EEEEEEEEEEEEEEE!

You pull up to a stop light in your freshly detailed shiny GT-R, with a nice long fierce brake squeal. Everyone parked at the stop lights looks side to side expecting to see a crapy old beater minivan, instead they have to do a double take when they realize it some kind of fancy new sports car. How embarrassing!

To eliminate this noise we have to understand what causes it.

Most average modern cars today use ceramic compound based brake pads, with low metallic composition. They are designed for the average driver - one who will ride the brakes to come to a slow gradual smooth stop; will never warm up the brakes despite the outside temperature or wet conditions; will occasionally do a hard cold stop, usually in an emergency situation, when the brakes are also cold and expect excellent results (cold bite); one that will expect the lowest dust and noise possible; and want the brake pads and especially rotors to last forever. 

The GT-R uses semi-metallic compound based brake pads with a high metallic composition. They are designed for very quick hard stops and absolute last minute braking, not a gradual stop. They are meant to work well under extreme temperatures, dissipate heat quickly and in fact work better when warmed up. Every stop is basically an emergency stop and no design thought is given to the life of the pads or the rotors. They are absolutely horrible when wet. (Recall the brake feel immediately after coming out of the car wash.)

There is a compromise scale in play here:
More metallic composition = greater squeal = greater hot stoping power = worse cold emergency stopping power.

I now use Endless MX72 pads with stock rotors, which are slightly more aggressive than stock and believe this is what Nissan should have delivered with the car. As a comparison, the Endless ME20 pads have a higher metallic compound and have better bite for track but squeal way more on street. And the Hawk HPS have lower metallic compound, low dust, great cold stopping power but do not last on the track. Is the pattern of what traits go together slowly developing?

If you use the GT-R for daily driving, the OEM pads are abrasive enough, due to the high metallic composition, that the pads actually grind down the rotors ever so slightly (fractions of micro-millimeters). This metallic pad compound to metal rotor grinding is actually what causes the squealing noise. Mystery Solved.

How do we stop it? Simple. We stop it by Bedding-In or Burnishing the pads against the rotors. This means putting some pad material onto the rotor by heat transfer.
  1. I assume you start with a clean washed wheels all brake dust removed, and at least 50% pad life. 
  2. Find a nice long country road with no traffic and a 10 minute route for no stopping right afterwards. Read the rest of the instruction to realize why.
  3. Turn your MFD Screen to "B".
  4. Check your front and rear view mirror for traffic. Accelerate to 70 mph quickly and slow down very quickly to 10 mph, and DO NOT STOP completely. It should be hard enough braking that you can almost feel the ABS kick in. It's okay if it does, but avoid it next time. My MFD braking "B" screen with the G-meter shows almost 1g of braking force.
  5. Check for traffic! Do it again 4 more times for a total of 5 times. You might smell some burning and even see smoke from the wheels. This is normal. DO NOT completely STOP the car. You will notice the GT-R brakes bite more progressively i.e. 1.1-1.3g and result in shorter stops. 
  6. Now drive at 50-65 mph for 10-15 minutes to cool the brakes down. This should not be stop-and-go traffic as it will scrape off pad material that was just laid down.
  7. Of course if at any time you need to use the brakes to stop or in an emergency, use them. 
  8. I have noticed that the brakes might still squeal a little, but will absolutely stop squealing after the GT-R has been parked and the brakes are back to ambient temperature.
I have done this procedure countless times, especially the evening before the track day to optimize the braking, or if the squealing is very bad, and it has stopped the squeal every time. The rotors should have a nice bluish (MX72) or brownish color (Stock) on them instead of the shiny silver color or new rotors. As per the pictures below.
Pad Material Transfer But Fading after 3 weeks of daily Driving
However, what happens over time with daily driving is that, with the repeated cold stops and gradual stops, the burnished layer get scrapped off the rotors slowly exposing the shiny naked rotor surface again, essentially the semi-metallic pads are turning the rotors and now we are back to the squeal.  Time for a repeat of the procedure. You can minimize the "un-burnishing" by making harder daily driving stops, but you run the very likely risk of someone rear ending you. 

Also one might  wonder if re-bedding-in or re-burnishing is eating up pads, indeed that is true, but relatively speaking each front rotor (one side) is about $1100 (stock) and set of pads (one side) is about $245 for MX72. I would rather go through 4-5 sets of MX72's before having to pay for complete rotors and avoid the noise combined with exceptional stopping power.

Once you understand these braking concepts, you may actually be okay with moderate squeal, as I am now, on a daily basis and recognize what needs to be done to solve the problem if it becomes too much.


ANNOYING SOUND #4: CLICK CLICK CLICK WHEN TURNING

Ever encounter a vehicle with bad or worn out CV joints. When a full lock low speed turn is made, a horrid click-click-click sound emanates from the front wheels. This sound is very similar to what is heard from the GT-R under similar conditions i.e. full steering wheel lock turns at slow speeds e.g. pulling in and out of a parking spot or maneuvering around a parking lot. Personally this is the worst of the noises covered thus far. I can live with #1-3, but not this one. This is not the attention I want. It never seems to happen on high speed turns.

To re-create this noise. Simply find an empty parking lot or similar structure, windows down, turn the GT-R steering wheel fully in one direction and perform a slow turn ~5-10 mph in the forward direction. Now perform it in reverse. Turn the steering wheel fully locked in the opposite direction and perform the same procedure - forward and reverse. In 1 up to maybe all 4 directions, you may hear a distinct click-click-click noise emanating.

The first time I heard this noise, I was certain that one of the front CV joints was gone, on account of the GT-R being a 4WD. I took it in to the dealership, the GT-R master technician double checked all drive and suspension components and found nothing awry. TechLine's suggestion was to clean the surface between the wheel and the rotor, as there is visible silver deposit from the wheel allay material on the black rotor surface and re-torque the lugs to 98ft-lb, the specification. 

Surely it went away, but to return a few weeks later. The suggestion was again to clean and re-torque to 102 ft-lb, then 104 ft-lb, each time the noise would go away for a few days. At this point, the stud holes on the alloy wheels were developing a small but distinct lip from the additional re-re-torquing of the lugs. I had enough and decided to get to the bottom of the mystery myself.
Continual Re-torquing eating away wheels 
I considered and experimented with multiple causes including but not limited to:
  • Changing out various front brake pads types Stock to MX72 to ME20 to Stock.
  • Tightening the hat bolts on the rotors.
  • Smoothing the back surface of the wheel with an orbital sander and high grit sand paper, trying it with and without lubricant.
  • Removed the little cylinder and bolt that is attached to the outside of the hub and prevents the rear wheel from being mounted to the front hub.
  • Putting high temperature brake lubricant on the back of the brake pads and on the top and bottom surfaces of the pad that slot into the calipers.
  • Making a mark on one wheel stud and always ensuring the wheel went on the same way.
  • Swapping wheels left to right, swapping from my summer set to my winter set i.e trying different wheel sets.
  • Putting a small amount of lubricant on the wheel surface that makes contact with the hub.
The Hats cannot be the reason because the rotor simply doesn't have much room to make that noise:

Ironically, everything seemed to work but only temporarily and the noise came back the only lowest common denominator was that the wheel was removed and put back. It then dawned up me that that every time the wheel is removed or any work is done floating rotors move ever so slightly. So as a paid service to my dealership, since it is not considered a warranty fix, I had GT-R master tech removed the rotors completely off the hub and realized that there was a considerable amount of rust on both the hub and rotor; the back of the rotor which looked like nooks and crannies of an english muffin. 

Rust on the Back of the Rotor
Due to all these hardened 'rust bubbles' the rotor never makes good contact with the hub even at 104ft-lb. Over time more rust develops due to the gap and causes the clicking noise. This is considerable rust, on the left rotor the rust was at least 1mm thick, which is too much for surfaces that should be flush.
Rust on the Hubs
Why is it more pronounced after a track day or the day after a wash? Simple. High temperatures and water accelerate the rust process considerably. Chemistry 101.

I asked the GTR master technician, to clean the surfaces of the hub and rotor with a wire brush wheel and put some Permatex 24125 Extreme Brake Parts Lubricant, and put everything back. The shiny show how much rust had to be removed to make the surface smooth:
Rotors Rust Cleaned Up
Front Hub Rust Cleaned & Permatex Added
This was done in back June 2012. 

The vehicle had exhibited absolutely no signs of of the click-click-click noise for about one whole year. It has been through two track events, multiple spirited driving events, multiple brake re-bedding-in, changed wheels to winter, driven through rain, snow, salt, and finally multiple car washes including pressure washer to the wheels; and finally a change to summer wheels.


Recently (May 2013), I had the tires changed on the summer wheels from Dunlop to Michelin PSS. After that, a faint clicking noise started and progressively got louder in the coming weeks. Ironically, the wheel to hub surface was already cleaned and "re-greased" by my dealership technicians when the tires were changed, and the clicking noise was still present. 


As usual the solution was to clean the wheel, re-lubricate and torque to 104ft-lb. I could pay for a time-based service to ask for hub re-greasing, but instead I decided it will make for a great DIY as I estimate al least 50% of GT-R owners probably have this issue.


So here it is:


DIY - HOW TO ELIMINATE THE HORRID CLICK CLICK CLICK NOISE FOR A VERY LONG TIME

STEP 1: Preparation and Tools


You will need the following tools for the job:

- Jack, Jack Stand, Chucks, etc.
- Hammer and Punch
- 3/8" Ratchet and 2 1/2" extension, 10mm, 12mm and 13mm socket
- 10mm HEX 1/2" drive with 1/2" Torque Wrench
- 2"-3" 1/2" drive extension and Lug Nut Socket
- 2 to 2 1/2 Ft Bungee Cord
- Permatex 24125 Ceramic Extreme Brake Parts Lubricant
- Cordless Drill with 2" Wire Cup Brush
- Small Screwdriver
- Fine Grit sandpaper
- 2-3 Cans of Brake Parts Cleaner
- Rags
Tools for the Job

STEP 2: Removal and Marking of the Wheels


- Put some chucks on the back wheel

- Loosen the lug nuts on one front wheel 
- Jack up the side of the car
- Remove the wheel.
- One of the five studs, there is a black mark. I always make sure to place the wheel on the same stud by using the valve stem to match the stud with the black mark. See picture below.
Anatomy & Removal
STEP 3: Removal of the Pad Pins, Tie Rods & Brake Pads.

- Using a Punch remove the two pad pins from the caliper by hammering them inwards.

- Remove the Cross Springs from the tie rods.
- Unbolt the tie rods from the back and slide them outwards.
- Slightly press the brake pads against the pistons, wiggle them to loosen them i.e. away from the rotor and then slide them out of the caliper. Wiggling them slightly pushes the caliper pistons in. Mark which one is the inner and outer pad respectively, they should go back the same way.
- Next, slide the rubber grommets  that hold the ABS Sensor out of the bracket as shown by #1 &; #2 in the picture below.
- Separate the 2 brackets, by removing bolt marked #3. This may cause the entire bracket to bend, avoid that. you may need a few drops of penetrating oil on that bolt #3, then work it out slowly.
- Remove the bolts holding the bracket to the suspension arm marked #4 & #5 below.
Removing The Brackets

STEP 4: Removal of Brake Calipers (without draining the brake fluid)


This is the trick to making the whole procedure easy. The service manual will state that all brake fluid must be drained but who has time for that.  We are not going to do that. Instead, we already unbolted the bracket that holds the brake fluid lines.

- Get the bungee cord and carefully slide it through the middle part of the caliper and then loop it around the suspension arm and connect it to itself. The bungee cord cannot be too short long, cannot be too weak or too tight. The objective is to keep the caliper (and therefore the lines) as close to the original position of the vehicle as possible. See below.

Install Bungee and Note reference of rotor position on hub
- Next loosen (not remove) the 3 bolts - 2x 10mm Hex bolts and the other bolt holding the caliper.
- Now Remove the bolts in the order shown 1, 2 & 3 completely. 
Caliper Removal Bolts
The Caliper should be able to hang freely, off the rotor and the rotor should be able to be removed very easily off the hub as shown below. 
Important: Note the relative position of the rotor on the hub, use the stud with a black mark & steel cylinder bolt on the rotor for reference (or if you have removed it then use the hole). As you can see most of the old Permatex from a year ago has melted or been washed off, hence the clicking has started again.


Rotor Removed.

STEP 5: Removal & Cleaning or Rotors, Hubs, Calipers, Pads, Studs & Wheels

- Clean off the hub (old grease)with brake parts cleaner and a Rag
- Now Using a Using the Cordless Drill and cup brush clean the hub surface thoroughly by running the brush on each stud. Then clean the surface once again with some brake parts cleaner. Be sure to clean the threads of the studs with the rag and cleaner.
Cleaning Wheel Hub
- Clean the back & front surfaces of the rotor that make contact with the hub and wheel with the brush. Then clean with brake parts cleaner, make sure to get the inner surface of big hole in the center of the the rotor that slots into the hub. Now would also be a good time to also use a small screw driver to unplug any clogged cross-drilled holes of the rotor.
Cleaning Rotors
- Feel free to clean the brake dust on the calipers, inside the grooves of the calipers that are usually hard to get to with the wheels on, but be sure to NOT move the calipers must as undue stress on the brake lines is to be avoidedAlso do NOT spray brake parts cleaner onto the calipers directly to avoid having the cleaner make any contact with the 6 rubber seals of the caliper pistons. Now would also be a good time to make sure all seal are in good working order. One of them was showing signs of slight wear. Not too worried as they are dust boots.
Clean Rotors, Examine Seals
- The back, top and bottom surfaces of the brake pad backing plate can be cleaned too. Do not spray any cleaner on the actual pad material.
- The wheel surface with a fine grit sand paper lightly, clean any lubricant and dirt from the stud holes in the wheel as you want to prevent that from depositing on the studs when reinstalling. Use brake parts cleaner and rag to wipe off everything.
- It is worth cleaning the threads inside the lugs too with brake cleaner. Basically the threads of the lugs, studs and wheel holes should not have any lubricant present.
Clean Wheel Inner Surface.
STEP 6: Re-Installation of the Rotor

- Put a layer of Permatex compound on the hubfirst, be sure to cover the round center part of the hub, but be sure to NOT to put any on the stud threads, if some does get on, clean with a rag damped with brake parts cleaner. (
See the picture a few paragraphs above to see the quantity) Useing a finger is best to spread it evenly rather than the brush.
- Put a thin layer of Permatex on the inside of the rotor, be sure not to get any in the stud holes of the rotor. 
Permatex on inside of rotor
- Put the rotor back onto the hub in the same position that it was removed using the bolt & cylinder (or bolt hole) and black marked stud as a reference.

STEP 7: Re-Installation of the Calipers


- Put the longer 10mm HEX bolt on the top hole of the caliper, the shorter one at the bottom. Then the center one. In that order. Tighten in the same order to 74ft-lb for the top and bottom Hex bolts an 18 ft-lb for the center bolt.

- This is a little tricky as the bungee will have moved to the top of the caliper, unhook the bungee cords and work the hooks out without damaging any piston seals. This might require some stretching wiggling.

STEP 8: Re-Installation of the Pads, Retaining Parts


- Put a very light layer Permatex on the thin top and bottom surfaces of the pad i.e. the surfaces that slide into the caliper. Put a very light layer of permatex along the backing plate of the pad that makes contact with the 3 pistons. This may help with somewhat with squealing sound. See below. Make sure no Permatex comes onto the pad surface.

- Slide the pads back into the caliper in the same position that that came out from i.e. inner and outer ones as marked before. You may have to wiggle the rotor to get the pads back as we did not compress the pistons back. Be careful not to let the pads catch on the pistons when sliding them back.
Note not to press any one piston in or all or them in considerably as this may cause brake fluid to overflow in the reservoir.
Permatex on Pads
- After cleaning the tie rods, insert them back in. Outside to inside. Attach the bolts and torque to 22 ft-lb.
- You may choose to put a slight amount of Permatex on the center part of the tie rods where the cross springs attach to the tie rods.
- Snap the cross spring(s) back onto the tie rods, if only one then it goes on the bottom with the arrow pointing down.
- Insert the Pad pins, one at a time from the inside of the calipers: through the inner pad, through the cross spring, through the outer pad and finally through the caliper hole. Hammer gently from the inside without damaging the calipers until the pins are all the way secure.
- Tighten the bracket bolts that were removed in Step 3 in the reverse order 5 --> 4 --> 3
- Return the ABS sensor cable grommets which were removed in step #3 back # 2 --> 1.


STEP 9: Re-Installation of the Wheel


- Apply a very light layer of permatex on the inner surface of the wheel/rim that makes contact with the hub, ensuring that none of it goes into the wheel hole studs. If it does clean it out.
- Re-Install the wheel in the same position as it was removed using the stud with the black mark as a reference point. For my GT-R the marked stud always coincides with the valve stem.
- Torque the wheel lugs in an alternating pattern  1 --> 3 --> 5 --> 2 --> 4. Or in other words skipping a lug until you come all the way around, they need to go to 98 ft-lb. I prefer to do this while the wheel is still up in the air. It is a little tricky as I have to hold one of the spokes with 1 hand and the torque wrench with the other.

STEP 10: Testing

- Repeat the Procedure Steps 1-9 for the other side.
- Test by performing the turning procedure highlighted on the top of the topic by performing full lock turns in each direction.

I can't provide any guarantees, but personal experience has shown that this is the been the only fix that has lasted the longest time without the issue coming up again in a short time.

When you start hearing little rocks and debris being kicked up and hitting the wheel well instead of the horrid clicking noise, hopefully it will bring a smile to your face too.