fattah089

Ok so my new transmission that has 3000 miles on it is starting to make noise again. I just want to double check i am driving correctly. The only 2 things that i do that i can possibly think of that can hurt the trans/clutch are:

1) Get out of gear without pressing the clutch down. (Like if i'm coming to a stop and i'm in a gear i'll push it to neutral without clutching) AND i only do that VERY VERY rarely.

2) Downshifting - When i want to downshift i usually put it in neutral rev it up to the correct rpms needed then i clutch and put it into gear.

I cant really think of anything else i'm doing wrong.. is this bad? i'm ok?

Thanks

jtree007

1. Not good for the transmission,but does not explain any reason for any problems.

2. Good for the transmission. Rev matching helps relieve stress on the transmission.. and even more if you are double clutching... gear, clutch,neutral,rev, clutch, lower gear.... then you are putting the least stress possible if done correctly...

chrisv

To do this you still have to kind of sort of match revs. Before you get out of gear you should press on the gas ever so slightly. This will ensure there is no torque between your engine and your wheels. The way you know you are doing it right is that if you are doing it right there should be almost no mechanical resistance to putting it in neutral (it should feel as if you were pressing the clutch).

Dipstix6996

iTrader: (3)

For you uneducated guys, read this thread about double clutching.


https://www.myg37.com/forums/showthr...=double+clutch

bboysteele

Always use your clutch when taking the car out of gear especially if you are a noob. I am also not a big fan of downshifting to break. There was a big thread about this so do a search for it if you want. Don't need another one of those threads. Here is part of an email I got from Nissan Sports Mag. I get their email newsletter:

Will heel-and-toe downshifting help slow the car down faster? That’s a common misconception. Downshifting to slow your forward progress went out of favor over a half century ago. I certainly would not recommend abusing your Nissan’s transmission to accomplish what modern brakes were designed to handle in the first place! Even for those who have a disc-drum combo or the non-Brembo OEM brakes on a 350Z or G35, braking efficiency remains the key. Threshold braking means that you have brought the car to the very brink of lockup, but not over. You can’t gain any more braking force at that point! If you are in an ABS-equipped car, you will be able to clearly discern the pulses through the brake pedal when you are in this area. Otherwise, you will feel (and possible hear) a wheel lock up. You must immediately ease a small bit of pressure off the brake and get the tire rolling again. What a proper heel-toe downshift does promote is a smoother transition from braking to cornering to acceleration. (David Muramoto, Summer 2005, SZM)

I now brake by leaving my car in gear and pressing on the brake. I then take the car out of gear when I get close to a stop or the rmp range gets close to 1000. I am always prepared to put it in gear though if something changes in the road that I need to respond to. I don't recommend that you take it out of gear for this reason. Leave it in the gear you are on and just slow down in that gear and be ready to downshift if traffic starts to flow again. I don't downshift anymore to slow the car because that puts more wear on the transmission. I would rather replace brake pads then transmission parts. Plus the brakes on the G37 are great so that won't be an issue. This comes down to personal preference so do what you want.

DetroitG37Joe

iTrader: (2)

Adam - the tranny noise is either a massiv design flaw that Infiniti is aware of but wants to avoid - or it's a normal nature of the car...I dunno but all of us 6mt'ers have it and remember how mine was quiet at ur house cause I only had 2-thousand-some miles on it then??? Well now it's almost the same as yours was before u turned it in lol....well its like 80% there. im at 4,500 miles now. guess we just have to put up with it bro. The only fix i can think of that actually seems less extensive than a whole tranny replacement - is the fix that Carolyn aka PMS1212 got:

https://www.myg37.com/forums/engine-drivetrain-and-forced-induction/181811-my-g-got-operated-on-success.html


But some are saying even that fix either doesnt last or work.

I am like F U C K it about it now. I got my JWT pop charger on order and my Tanabe exhaust on order. Once my baby get's louder maybe the tranny noise will just blend in with the louder idle for a combined beastly idle noise. haha.

TomG37

What does the noise sound like, my car already has the flywheel chatter.

GiGGaplease

never heard of the first method. didnt know you can take the gear out without the clutch. i rarely downshift, whenever i do, i just press in the clutch and downshift. there is reving or anything. do not know if its right but its a habit now. when im coming to a stop, i would just put it out of gear like 20 car links before stopping and cruise to a stop.

weave

I honestly think this is the nature of the beast. This transmission is noisy and I am more than sure Nissan knows it but either a) chooses to ignore it or b) cannot find a fix for it.

As far as down shifting.....if you are planning to drop from a higher gear to a lower gear, you need to use the clutch. This transmission does have triple coned synchronizers for 1st, 2nd, and 3rd gears so in theory you can down shift with no clutch so long as you know what you are doing......in fact this can even be done with a single coned gear if you are good at rev matching.

In theory (really fact) you only need a clutch to start and stop the car to prevent engine stall....but these transmissions are not made to take such driving (not a real race car) and would not last under these shifting conditions. The whole theory behind shifting is to speed match the parts that will be connected to prevent grinding. When you push in the clutch, the input shaft is disengaged from the engine and the internal parts begin to slow down (as well as not having torque applied). The next step, as you begin to push on the shift lever, will move a rod connected to a fork, that is on a hub (lots of parts here). This hub sits in between two gears and is what is used to push the hub sleeve over said gear and "lock it in". The synchronizers are in the middle of this to assist in slowing down and assist in speed matching the moving parts to provide a nice smooth shift into the selected gear.

Now, popping the car from any gear to neutral with no clutch, that is not going to hurt a thing....ever!!!

As for the noise. This is going to be from any one of, or a combination of all, things. 1) There tolerances are less than optimal in these units. 2) The bearing are junk. 3) the fluid is not best suited for this unit (too thick, to thin, not slippery enough, too slippery, etc...).

As for getting this fixed...unlike when I was a technician (no one seems to fix anything anymore, they just replace it all) you are going to get ignored or you are getting a whole new unit.

Peace

DetroitG37Joe

iTrader: (2)

https://www.myg37.com/forums/showthr...=182441&page=2