I'm going to attempt this over the weekend. I think it might be a combination of old diff/tranny/engine fluid too, so i'll have to flush and fill up that over the weekend too. I'll post up the results. Again spec-01 thanks for the help! I think this is what i'm looking for since it is hard to shift into gear even though my clutch is fine, but we'll see. I also have a service date on Monday, maybe a new transmission on the way, maybe..

 

Keep us posted! Thanks...

 

does/did any of your trans make a metallic bearing/diesel like sound at low RPM before or after the replacement?

My replacement trans is making a rather loud bearing/diesel like noise when under 2krpm or so at accelerating moderately+ which my original did not have any sounds like this atleast not to this sound level.

 

I am really beginning to think that there are a number of issues relative to these widespread transmission woes. I say this because the sound you describe seems to be gear noise, which is generally not an issue when using the stock dual-mass flywheel. I assume that you are currently using the stock clutch and flywheel assembly, is this correct?

If my above assumption is right then you really shouldn't have any gear noise, as this is one of the things that the stock flywheel is intended to dampen. This means that it is possible that you are hearing this noise as a result of several other possible causes. These could include, low fluid levels in the transmission, lesser tolerances in the transmission gear set (which would allow for more movement and thus increase gear noise), a dual-mass flywheel that is no longer functioning properly, or it could even be completly unrelated to any of these things and be the result of a heat-shield that is loose and vibrating.

I would start trying to narrow these things down to determine the actual cause. The easiest way to do this would be to take the car back to the dealer and let them have a look and listen...see what they think and go from there. I hope this info helps. Let me know if you have any further questions. Thanks!!

 

lots of good information there. I know that the tranmission is new and replaced, not sure if that has any affect on anything. You are correct I have the factory clutch and flywheel, which was replaced at the time of the trans replacement as well. My shifts are better than the original unit, however now I have what seems to be gear noise and occasional clutch chatter (which I never had before), today it actually seemed to chatter the most than it has in the past while.

It is like I went from one extreme to another; quiet with some shifting issues to better shifting but noise an annoying as hell. I don't know if it is just me thinking to much but it almost seems like it feels slower and the exuast tone might be a bit different....Who knows.

I will have to call the dealer and see when I can bring it in and hopefully get good news from them rather than bad.

Thanks again, I will keep you posted.

 

I've learned to live with the chatter and rattling noises coming from these transmissions. The more you worry about the sound the more you go crazy. Mine made strange noises since the day I drove it off the lot, and I've driven several Z's that did exactly the same thing. Unless it is *grinding* when you shift, you're fine. And now that I have a lightweight flywheel the thing sounds like a mack truck under 2k rpm and chatters to all hell when engaging, but it shifts and drives just fine. Get a louder exhaust or maybe a honda accord if it's the noise bugging you

 

Mine sounds like a mack truck and it is using the OEM clutch and flywheel. The part the annoys me is the original clutch and transmission never made any such noise, and now the new setup is loud as hell. That is what annoys me, if it had it always that be one thing.

Before this I had a 99 infiniti G20 that had 115k miles on it at the end, that started giving me problems with a small exhaust link check engine light about misfire and it sounded like a mack truck too. Now my new replacement car is begining to sound the same and sound like it is tearing itself apart when I leave every stop or accelerate gently out of any turn.

I thought maybe I am wrong in my assestment and maybe the engine is pinging, but I dont think it would sound this way but I dont know anymore. Maybe they never filled it with enough fluid. I know when I first got the car back I found the White insulation from under the shift boot on the passanger side floor, when I took the shift **** off to put it back on it came off real easy. I found the spacer ring was placed upside down as well. Who knows what else may have been missed/forgotten ....

 

Ive had the same problem on my 05. I Had a tech tell me the same thing. I called Nissans consumer affairs and had an regional service manager hear me out. There was about five infiniti representatives in the office at the time of my rant. Needless to say, with all my prior clutch complaints and calls to consumer affairs, they replaced my throw out bearing, pressure plate and master cylinder for free. Im still under warranty though. It took me about a year to get this done as well. I do agree with your statements. My tranny does sounds like rocks grinding when shifting, 1st gear going to 2nd feels like there's something blocking the shift and I do here a loud clunking noise at times when I put it in neutral. After having this car for over two years, I still feel like i'm learning how to drive my car. Sadly, most techs and some members hear can vouch that these trannies are loud and it "normal." That said, all I can say is get used to it, get an aftermarket clutch/rebuild your tranny, or sell it. Good luck

 

Yeah, that is why I figure. I remember hearing alot about that before. I can live with it for sure, i just don't understand how my last setup could of been so much quieter compared to this new setup, from a logical standpoint it should be reverse.

I also noticed that they had way too much clutch fluid too from when they must of bled the line. cause it was filled to the cap (this was checked in the morning before the car was even run)

Oh well, I will still contact the dealer and see what they say, can't hurt to check since I am still under warranty

 

The guide plate fix didn't seem like it worked for me. Thanks for trying spec-01. Instead I took the car to another dealership. I dropped it off two days ago, and still no word. Not sure what they'll tell me, I know they probably found the problem, but we'll see..
Updates to come.

 

I want to make sure that you all understand the potential causes for a few of the issues you have mentioned, in hopes that it may help you to better understand the associated problem and the suggestions/recommendations made by your dealers.

To begin, let’s define a few terms:

-Clatter: a.k.a. gear noise, "concrete mixer", "marble in a tin can"
This sound originates in the transmission and results from weak tolerances that allow for increased harmonics. Most OE manufactures will use a dual-mass flywheel to help dampen this noise. It is important to note that this sound doesn't evidence an issue...but that it can be annoying. Use of a thicker (more viscous) transmission fluid can aid in reducing this noise.

-Chatter: a.k.a. shudder
This sound (which is often accompanied by a vibration that can be felt through the pedal, the shifter, the seat and the steering wheel) originates as a result of several causes and can be more prone when using higher-friction coefficient disc materials and higher-clamp pressure-plates. This symptom can also result from a disc that is not fully seated and in these instances it will generally reduce as wear-in occurs. Chatter is normally felt when leaving from a stopped position (1st and Reverse) and will generally be felt during clutch engagement (while you are releasing the pedal) only.

Other possible causes for Chatter are: bent clutch disc or cover, contamination on the friction surface, damaged or worn engine or transmission mounts, etc...

Chatter is not a common occurrence with stock clutch kits. If more people report this issue after having new stock clutches installed then it is safe to assume that a change has been made in regards to the materials or the pressure-plates used by the OE provider. Keep in mind that these cars are now equipped with a SAC adjusting pressure-plate (see below), a change that occurred between 2004 and 2005. All 2005 models should have been equipped with this type of plate. As far as I know all replacement clutch assemblies from Infiniti are of this design.

-SAC (Self-Adjusting-Cover) Pressure-Plates: no known alias
This type of pressure-plate is becoming the norm with many luxury automakers. Pressure-plates of this type have a sprung adjustment mechanism that is intended to maintain a consistent engagement point as wear occurs, eliminating the tale-tell high-pedal commonly seen in cars that have a worn clutch. SAC Pressure-Plates have a potential for miss-adjustment when installed with used flywheels, as flatness affects the adjusting mechanism. Miss-adjustment will lead to a clutch that does not fully release or engage. SAC-Plates can also increase the chances for Chatter (described above) if miss-adjustment occurs. Most aftermarket clutch assemblies will be based around non-SAC Plate designs.


-Dual-Mass Flywheel: a.k.a. boat anchor
Dual-mass flywheels were developed to dampen gear noise and clutch engagement. These units have a much higher weight than similar single-mass flywheels. The name "Dual-Mass" refers to there two-piece design that comprises two halves (Planetary and Secondary) that are joined by a series of torsion springs and cushions. Dual-Mass flywheels provide maximum isolation and frequency dampening of engine vibration, gear noise and engagement...but they also sap the transmission of power from the engine to the wheels because of their excessive weight.

Now that we are on the same page when it comes to the terms being used we can proceed with further application of these terms to the context relative to the widespread transmission woes mentioned here.

As I said previously I suspect that there are several different issues that are causing problems with the Getrag Transmission used by Nissan and Infiniti. The sound and vibration that some of you have experienced are potentially related to issues of failed or improperly functioning Dual-Mass flywheels and/or transmission fluids that are not meeting the demands or requirements of the transmission. Other possible cause are relative to the transmission itself and as previously discussed Nissan and Infiniti are currently replacing transmissions rather than rebuilding them.

Though there is little to no likelihood that the common issues of problematic gear selection are related to the dual mass flywheel there are a number of other possible causes. These include but are not limited too: improper lubrication or insufficient lubrication by the specified gear oil; weakness of the specified synchronizer (material or design) and subsequent premature wear; weakness of the specified transmission selector forks; misadjusted/misaligned shifter guide plates; weak slave or master cylinders or air in the hydraulic system; etc, etc, etc...

Ultimately any of the above issues could cause problems with gear selection. At this point Nissan and Infiniti are replacing transmissions under warranty and because the majority of these cars are likely still within the 70,000 mile/7 Year Drivetrain Warranty the problem has been masked. It is my guess that as these cars age we will see a much louder outcry for resolution to the problems at hand. Eventually people are going to have to buy these transmissions as replacements because they aren't under warranty any longer and when this occurs...we may finally find out what the cause actually is.

I hope that this post has benefited someone...as it took forever to write. I will let you all know if I personally experience any other issues with my G and I will also help you all with trouble shooting as needed. Please feel free to contact me with any questions you may have. Thanks!!!

 

Wow man. that is amazing source of information! I knew a good amount on the dual mass flywheel (impressed the shop manager at the dealer) but had no idea about the SAC pressure plate.

Many thanks! You did make me start to think about the MT gear oil. Perhaps my original trans didn't have the noise from the past owner potentially replacing the fluid with something of better grade that helped to minimize the noise. or the new fluid is crap compared to what the car originally had.

Again, awesome info man!

 

Yea good info. My tranny is noisy, chattery, shuddery, and just about everything else listed here but there are no issues changing gears or engaging. I've found that driving like a bitch is the main precursor to all the issues...it likes to be driven hard and engaged quickly

 

I too have a 6MT in my 03 sedan with about 97k; I have found when I baby it, it gets crabby and acts up with many of the issues spoken about. When I drive it hard, it rises to the ocassion and is a champ.

"Drive it like it's stolen!"

 

Well it's been a few days since I dropped the car off. Missed a call from them today, so I might get my car back soon, but I don't know if they fixed anything. If you drive the car harder it makes sense that it becomes smoother, but there shouldn't be any reason for it to become worse to drive when you don't push the car.

Updates to come.