[[email protected]]

I'm not to GTR's and new to this forum but have seen some very helpful posts on here. I have an '09 JDM, which I bought in sept'13 with 22000 miles. It was stock when I bought it and it has now done 28000 miles. I have never racked it or launched it but I have not doubt it has had both done (probably lots) prior to me purchasing it. It has always had a prominent 'binding' noise (most noticeable in low gears at low speeds - probably due to reduced cabin noise) which I have been told is one of the many 'normal' noises. I changed the bell housing but this did not help significantly. After its 24000 mile service (including TM oil change) I noticed a 'squawk' when changing from second to third at 4000-6000 revs and maybe a slight delay in the change. I had Litchfield look at the gearbox; they could not find anything obvious but replaced the cir clips, solenoid and ends?, as well as the 3rd gear and synchro. Unfortunately the noise persisted. They suspected it may be noise from the clutch (due to play in a part, the name of which I can't remember) - maybe the same noise as the 'binding' but at a higher frequency (maybe even resonant frequency?). They upgraded by TM software (2010?) but this made no difference. They also played with the clutch settings but this did not significantly effect the noise.

More recently I have noticed that the delay when changing 2nd to 3rd is more pronounced and on 2 occasions I have noticed changing into 4th is abnormal. This happens when I am accelerating moderately (75%). The change to 3rd is a bit slow and then when changing into 4th there is a loss of power and then 4th gear clunks into place with a jolt.

On another occasion it was as if there was no gear selected briefly (when changing 3rd to 4th), the engine revved, I reflexly took my foot off the gas and then 4th gear clunked into place with a jolt.

I have never seen any warning lights regarding the transmission and the car seems to drive fine afterwards. It has happened in auto and manual.

I wonder if this could be a clutch issue - maybe having difficulty binding/releasing?

Should I get a new clutch? Any recommendations for a clutch which has less 'binding' noise and room for modest power upgrades? Any other suggestions and opinions welcomed.

 

[Flash]

Maybe try a clutch relearn? That should help your 2nd to 3rd gear shift.

 

[[email protected]]

Already had a relearn a number of times although this was prior to the recent issues going into 4th gear.

I have disconnected the battery briefly to remove the seats - could this affect the clutch settings?

 

[Jacks Transmissions]

No, disconnecting the battery will not change anything.

I know what the problem is. My problem is I see a lot of people with your issue and when they take it to someone else, they can never figure it out. I am a nice guy, or really stupid, so I guess I'll share what it is to put you out of your misery. I just hope anyone that reads this with the issue will help support my free info in buying the needed parts from me.

The issue is with the clutch pressure plate. In the early trannies, the B clutches (or odd R, 1, 3, 5 clutches) have a clutch pressure plate at the top which measured between 2.3-2.5mm in thickness. This is too thin and will cause a vibration when the clutch is engaged at the perfect friction zone point. I call it the 'errr' noise. It doesn't hurt anything, but can be annoying for some drivers. The fix from Nissan was to increased the thickness of the pressure plate to 3mm. Due to this change, you see a lot fewer newer units making the noise, but some will still do it due to the design of the OEM frictions. The mix of a thin plate and poor design of the frictions cause the noise.

I have a fix for this. What I do is machine the clutch carrier, B piston and oil pump drive plate so there is more clearance inside the assembly. I then add thicker steels all the way down from top to bottom. I also upgrade older units to the 3mm thick pressure plate steel at the top and use my frictions that are a different design which will cause less noise at the 'friction zone'. I also have my own fluid which I helped develop to work better at high friction conditions to cause less noise.

IOW, if you buy a clutch and fluid from me, I go through all of the details to assure no chatter, no noise, and proper clearance and fitment. I am well aware of the issues which plague a lot of owners and have found ways of eliminating it. My clutch also shifts faster too

The way to verify you have the issue is if you hear the noise ONLY in the R, 1, 3, and 5 gears, or if you perform a simple test:

1. Find a steep hill and park on it with the front of the vehicle pointing down.
   
2. Put the car into reverse gear and try to back UP the hill.
   
3. Stop and go several times giving it more or less throttle each time.
   
4. You should hear the errr noise.

The reason this aggravates it to make the noise is due to the fact that R gear is taller than 1st gear. This puts more strain on the clutch and will upset it to make the noise. Trying to back up a steep hill will definitely piss it off.

If you hear the noise, then you just need the clutch reworked with the correct steels and frictions. It is not worn out or bad, but just a little noisy. If you don't mind it, then leaving it alone will not hurt anything. If it bothers you, then I have options below:

To remove the assembly from the trans is easy.
Oil Pan:

• Remove the pan first by removing the 21 pan bolts which use a 10mm socket

• Pull the oil filter DOWN an out. Nothing is holding it in, just pull:

• Locate the 16 pin connector circled in the picture below. Remove the connector bracket using a 10mm socket
• Disconnect the green 16 pin connector (located on the clutch cover side corner of the assembly)

• Jam the connector (coming in from the front cover) down into the front cover assembly cavity. This is to prevent it from snagging on the housing when the front cover is removed (prevent damage)

Front Cover:

• Remove the 20 bolts with a 12mm socket
• With a pry-bar, very carefully pry the case apart using the case areas designed for this

Removal:

• Very carefully pull the assembly out of the trans straight and out
• Be careful with the 16 pin connector and do not damage it
• TIP: Note the washer which is on the output shaft (the shaft which is sticking out of the trans). The washer needs to be installed with the tapered end facing toward the gear. If there is no washer on the shaft, it is still sitting inside the FWD unit. Pull it out and put it on the shaft (3rd picture).

Clutch Assembly Removal:

• Remove the 4 T30 bolts from the clutch valve body (arrows show which ones below):

• Very gently and evenly pull the valve body away from the case. It will be a bit tight.
• Remove the small clip from the input shaft found at the center of the clutch basket (circled below):

If you ship me the assembly you see in the picture above (arrow pointing to it) then I can perform my magic to it for a clutch that not only works like it should, but will also live longer. Here are options and prices below. Note, my price to machine, fit and test the whole clutch assembly is less than most clutch kits sell for alone. You get a real bargain from me with a lot of additional labor and machine work

We have the following below designed to hold at factory oil pressure levels:

Economy Series of clutches which include major machine work, laser baskets, new frictions and new steels:

600ft/lbs 12 plate $600
700 14 plate $1000
800 16 plate $1400
900 18 plate $3200 (includes billet baskets) Warning- this clutch is noisy!

Full 'Billet Series' which include lifetime redesigned piston seals (will last the life of the car), billet A and B pistons, 1-piece billet baskets, and 1-piece billet carrier:

600ft/lbs 12 plate $5400
700 14 plate $5900
800 16 plate $6400
900 18 plate $6900
1200 18 plate $7500
1400 20 plate $8500

I believe your 3rd and 4th gear issue has been aggravated with people replacing synchros and trying to change things unrelated to the clutch noise. With your description of the shifting issue, a few things come to mind:

1. Your Touch Points are set too high. Put it down to 0, 0. If it is already there, try going down to -1 or -2 and see if the shift quality changes.
   
2. What are you using for relearn? COBB, ECUtek?
   
3. What fluid do you have in the trans?
   
4. Have you ever seen a clutch overheat warning in the dash?
   
5. Could be a warped clutch plate. Very rare in the GT-R, but it happens. A warped plate will put the synchros through a lot of strain and they will not be able to synchronize properly.
   
6. Valve body TSB been performed?

That's all i have for now. More info would help.

Good luck!

Jack

 

[lecsoman]

I had the errr noise and, after seeing the clutch first time it was clear why its present. I cant understand why someone working on the gtr clutxh cant see this...

Anyway, can you check mails jack? I sent about 6.