Tranny whining (not rattle) noise 350 miles after lightweight flywheel (+video)

[allmightsu]

Hello guys,

 

I wrote in the USA's forum, but unfortunately when I post the thread there, I haven't recorded the viceo and didn't really get any opinions. Later on I decided to record the noise and paste a video, but the viewers ot the video are few people, so I assume most of the people didn't really see that I pasted a URL. So sorry if some people already saw the thread there.

 

At first here is the video:

 

https://www.youtube.com/watch?v=IqZt4sYSdnY

 

 

I have a 350z HR, year 2008. It has 19k miles on it. I bought it like.. 4500 miles ago. For me, it feels like a brand new car..

 

Recently I installed a JWT lightweight fw & clutch combo as well as JWT HD CSC and Tilton master. So far so good. I did the break-in procedure and I was aware of the rattling noise (chatter), which is not that bad by the way.

 

So.. the break in process was fine, afterwards I've started to push the car harder without any issues (just the ratling noise) and the other day I went to some place to do few 1/4 miles starts (no drag tree and time counter). I did few starts and when I left the place I heard a whining noise. Ok.. some puley of the driving belt I said.. but few miles ahead I managed to observer that it is coming from the "after engine".

 

1) Anytime when I engage the clutch it stop;
2) It doesn't matter is the car moving or not;
3) It doesn't matter is a gear engaged or not;
4) It depends by the revs (it doesn't stop on 2500, but it goes up to... 4-5k. I cannot hear it after that due to engine noise);
5) It only matters if the clutch is engaged or not;

 

It is weird cause if the car is moving and lets say being on 3rd gear, engine is on 3k rpm and accel pedal is NOT pressed the noise could be barely heard.. and once I engage the clutch it fully disappear.

 

The whine is like a diff bearing, like a supercharger or like a straight cut gearbox. When car is not moving and I press the clutch, so the friction plate and the input shaft of the tranny stop spin, the noise disappear. So diff, engine and output shafts are not suspects. Neither the CSC.

 

The question is.. I know the rattling noise which up to around 2500rpms, but how likely is the tranny to start whine because of the lightweight SMF? Is this being part of the so called chatter?

 

It whine more on accelerating compared to decelerating (on the same revs). So what is being loaded more on accel than decel? when the torque is transferd from engine to tranny it whine more and when the torque is transfered from wheels to the trany (deceleration) it whine less. In both cases there is torque applied on all bearings in the tranny. Well ok, output shaft is more loaded than the input one. And vice versa.. the input is more loaded on accel compared to output one.

 

The suspects are:
1) bronze pivot bushing (it is the old one. I ordered Nismo needled bearing, but I decided to not put it, so I left the old bronze one);
2) some bearing on tranny input shaft went away recently;
3) noise is normal for single mass fw. I am doubting that, as the first 200 city miles it was not there. Just the rattling. Plus like 200 miles normal + hard driving. It went after the few starts I did the other day.

ALSO when I press the clutch while car is not moving I can literally hear the noise how is it stopping counting rev by rev. OK then surely this is NOT the CSC.

 

Gear engagement is like before. No issues at all beside a 2nd gear grind in high RPMs and quick gear change. I believe it is the synch that is making problems. But that issue is known to me from day 1 of bying the car (around 4500 miles ago). Sometimes 2nd goes with a grind.. sometimes it cannot be engaged at all and the grind is so so hard.. like teeth is hitting the opposite teeth. I am only wondering if this have caused some bearing degradation, due to the axial load that has been applied on the shaft while trying to engage 2nd gear. You know like.. trying to engage a gear without pressing the clutch. Maybe the sleeve is in contact with some other metal part.. who knows.

 

I bought new bronze bushing, so I will remove the gearbox and replace it. I will also have a look on the CSC and will spin the input shaft by hand.. if I can hear something. If the noise is still there after the new pivot I might revert to the stock dual mass clutch combo for the test. And if the noise is still there.. I will need to open the gearbox and investigate further the bearings, sleeve, synch, etc. Just this won't happen right now as I need to have more free time.

 

So yeah.. tue/wed next week I will work on that.. but till then I would be happy to hear some opinions.

Edited August 27, 2021 by allmightsu
Spell checking

[Coz@TORQEN]

Hi,

 

Supercharger whine?  Only joking , it's definitely not part of the 'chatter' as such, the lightened JWT kits are a bit noisier but definitely not what you've posted on that video. Doubt it will be the pilot bearing. Maybe try looking at the bearings for the input shaft like you said but I would've thought that would be more of a grinding noise.

 

It's one of those things that'll probably need the gearbox opening up to inspect it, could be a number of things and it's pretty hard to determine just by the sound. 

[ZMANALEX]

I would start by pulling the box and inspecting all the parts that you have fitted.

 

Also, I had a similar noise on a customers HR last year and it was the crank pilot bearing.

 

Opening up the gearbox is an option to be considered but only after you have discounted every thing else.

 

 

[allmightsu]

Hahaha, believe me, when I drove the car after that I felt like "ok, it doesn't feel like 450hp! It is 450 with that Vortex, right? Right!?". It sounds that bad, mate. 😃

 

Yep.. I am waiting to receive my hydraulic jack, as last time I borrowed one from a friend and then will pull the box down. Will inspect what I can inspect.. will change the pilot, at least I can easily do that. If the noise remains, I can put the stock fw and clutch for the test... then will need to open the box.

 

At least I wanted to verify that this noise isn't part of the "chatter". Thanks guys.

@ZMANALEX, by crank pilot bearing, you mean the bronze one, right? That the gearbox mainsfaht goes to?

 

Amm two more things

 

1) The only suspicion that I have is, if by not engaging* 2nd gear properly, something is now twisted or disaranged. Like fork, sleeve or a gear. And if there is some contact between metal parts due to twisting. Or some bearing is disarranged axially. But if that is the case, the noise should be there all the time, not only when there is a load from the engine. Or if there is a twisted fork or sleeve on a specific gear.. the noise will be only when this gear is engaged.

 

2) It is still confusing me, why if the car is.. lets say on 3rd gear, so both main and counter shafts are spinning, if I engage the clutch pedal so the traction disk is not pushed by the pressure disk anymore, the noise disappear. Even if I rev the engine with engaged clutch pedal.. everything is spinning (crankshaft, clutch, CSC, main/countershafts). The symptoms are just... amazing 😖

 

*By not engaging I mean.. the grind when a tooth meets the opposite tooth, like.. if you try to engage a gear by not engaging the clutch pedal. That painful grind.

 

 

Thanks for the answers, wish me luck. I will update the thread once I have more info. Hope it will not take too long.

Edited August 27, 2021 by allmightsu

[ZMANALEX]

11 minutes ago, allmightsu said:

@ZMANALEX, by crank pilot bearing, you mean the bronze one, right? That the gearbox mainsfaht goes to?

 

 

Yes the phosphorous bronze bushing that is pressed into the end of the crank which accepts the  front gearbox 1st motion shaft.

[allmightsu]

1 hour ago, ZMANALEX said:

Yes the phosphorous bronze bushing that is pressed into the end of the crank which accepts the  front gearbox 1st motion shaft.

 

Thanks. Fingers crossed!

[allmightsu]

Yello, yello,

 

A small update. Unfortunately, it is not the pilot. The old one looked really bad though. Buut.. it is not the culprit. The CSC looks good. The clutch pack also.. spinning the main shaft of the tranny by hand doesn't make any noises (but I can spin it that fast by hand either way).. so the next thing to do would be to open the gearbox.

 

While idling, I was under the car and I tried to listen to that noise using a metal bar touching different places of the housing/engine/tubes/whatever + I was listening in the car with an ear on the gear shifter while naked (without rubber, plastic and the gear knob)... and I can hear it pretty good while listening at the front bottom of the tranny. Like.. where the counter shaft bearing is. Of course it could pretty much just replicate the noise from some other place, buut, so far I am suspecting some issue with the counter shaft... yeah.

 

At least once I open the tranny, I will use the opportunity to change the grinding 2nd gear synchronizer. Hope it is just the synch, not the entire gear.

 

 

[Roscoe]

Sounds pretty normal to me for a HR variant. The HRs do tend to have a slightly more supercharged sounding gearbox than the DE’s 😄

Mine has always had a similar noise to that, I purchased it at 40,000 miles. Now on 85,000 miles and gearbox feels as smooth as it did back then.