UncleTrill814

Car: 1995 Integra GSR

I have a grinding noise coming from the trans that's only at certain rpm. This isn't a pilot or throwout bearing newbie question either. It doesn't matter if the car is in neutral or in gear, clutch engaged/disengaged, if the car is moving/parked, cold/hot. The noise started immediately after installing a new clutch (Exedy OEM) and flywheel (CB Haus 10.2lb). The noise only appeared between 1100-1350 rpm. Due to only having one running car, no garage or all the proper tools and even the time to take the trans off again I decided to drive it for 5k miles. No not the best idea, but the clutch grabbed fine and there were no other issues. The suspected culprit was that the flywheel could have not been torqued correctly (it was) or that it was not too the correct specs (it was).

Over the past two week the noise started very faintly at 2300-2400 rpm. I finally was able to line up the various things need and pulled the trans. No signs of premature wear on the clutch or flywheel. No metal shavings or odd dust. Flywheel and pressure plate were still nice and tight. Input shaft was loose and when spun it sounded like the bearings were loose and fell toward the bottom. Pilot bearing was a little bit rough to turn, but it certainly wasn't blow out or ruined. I happened to have an extra GSR trans so I replaced the rear main seal, throwout, and pilot bearings and installed everything again. I thought it was was weird that if the noise was the input shaft bearing why did it not make the noise before the new clutch/flywheel and only immediately following. After getting it all back together it still makes the noise albeit it's not as loud and the window in which it makes the sound is much smaller 1200-1300 and again at 2300-2350. I decided to not even drive the car and I'm currently borrowing one.

I figured if the flywheel wasn't put on correctly that the imbalance would cause some type of wear pattern on it but nothing was spotted. Do you guy/girls think that the flywheel was not balanced from the start and that having driven it 5k caused the input shaft to become loose? I'm going to buy a new flywheel under the assumption that that's what the problem is because I can't find any info anywhere of the same problem. Mechanic friend has never heard of this and suspects that I received a bum flywheel from the start. Also, should replace the clutch as well just to be safe? Like I stated above though, the car drove great and I had not issues with it performing its duty so I'm not sure if the clutch was damaged.

holmesnmanny

Maybe its a timing side bearing starting to make noise.

If it still makes the noise with the clutch pushed in it cant be the trans since the trans would have stopped spinning.

If you can make a real good vid that would help.

slowcivic2k

If the input shaft is loose the preload spring requires replacement, and you will need to adjust the free play of the mainshaft prior to installing the new spring. Find the cause of the slack. Normally the ISB is to blame.

Are all dowel alignment pins installed correctly? Short of serious disaster, or a lack of oil in the transmission, that is really the only thing to look at.

Buy quality parts from the start if you require them, or machine the existing flywheel. Any time this level of teardown is done, all parts in the vicinity should be evaluated for wear and corrected. There is no guarantee that a replacement flywheel will fit EXACTLY like the old one. If they had machines capable of that precision, recalls would not exist.

https://honda-tech.com/forums/tech-misc-15/transmission-bearing-failures-causes-explained-2051578/

holmesnmanny

He did specifically say that the noise is there with the clutch pushed in, so assuming that is the case, and it could very well not be, that would rule out the isb.

UncleTrill814

If the motor is spinning at the rpm's listed above it is making the noise. That's why I titled the thread rpm sensitive. That is the only cause of the noise. I don't think the ISB is creating the noise. I think it is the flywheel not being balanced that is creating it. I was asking that if the flywheel is imbalanced and if specific rpm's are causing a vibration, would that vibration cause the ISB to prematurely fail. Does this sound like a new flywheel could solve the noise or is it possibly something else?

As far as dowel alignment pins being installed correctly, you mean the ones used to mate the trans/block correct? The clutch/flywheel I replaced were OEM and I don't believe the trans had ever been off. It doesn't sound like the trans is not bolted together properly. I only use Pennzoil synchromesh in my transmissions and I change the fluid yearly. Axle seals were fine so they weren't leaking fluid.

I will try to get a video tomorrow after work when I go to where the car is and I'll have my friend upload it to YT and I can post the link here.

holmesnmanny

Explain exactly why you think that the flywheel allegedly being unbalanced would cause a grinding sound.

slowcivic2k

I was addressing a side concern: The input shaft being loose required corrective action. The information I have supplied is very basic and should be considered irregardless of the task at hand. I do apologize for any misinterpretation.

Given the information the engine itself or other engine components are to blame. This could be a coincidence. I personally find it hard to believe that a phantom engine noise would occur right after a clutch change, but I have seen weirder stuff happen. Most timing belt-style whine occurs just off of idle speed as you describe. I think retracing the entire series of events is required, or we need more information. (meaning video, audio) Please bring that in.

holmesmanny: I suggest you start providing actual input to the thread, or stop posting. You are providing no real help to anyone.

Oh, and BTW, an unbalanced flywheel or flex plate/converter can create metallic scraping on the rear main bearings. The noise may be harmonic or not with other engine components.

UncleTrill814

It's definitely not timing belt whine, if you're referring to the actual timing belt making a noise. Harmonics is the exact reason I thought it was the flywheel. Crank pulley and flywheel are basically tuning forks attached to the crank (as I've come to understand it anyway). My problem with thinking that a coincidence has occurred where an engine component has gone bad at the exact same time as a new clutch is that if this horrid noise did this immediately, why is the engine still going? I know "Honda reliability" but still, I've put around 5k miles on it like this and it runs the same as it ever did. It needs new piston rings and the valves need adjusted, but it certainly doesn't seem down on power or anything.

The friend whose house the car is at made and uploaded a video of the noise for me. The car was just started and running around 1250rpm at the time of the video. Not sure if the sound will be clear enough for you to distinguish what it is, but here it is.

holmesnmanny

Not quite sure who the hell you think you're talkin to. You're definitely not smarter than me so you can quit acting like you are. I understand you messed up in this thread and are now clearly upset as a result but i was very respectful in responding to you, considering how you could overlook something so minor.

If the flywheel was severely unbalanced or warped he would likely have slippage issues and/or clutch chatter.

Btw harmonic sounds do not sound grinding in nature...ie when idiots run without balance shafts

UncleTrill814

:Update:

Stopped by a local shop where one of the mechanics has been racing Integra's for about a decade. He's never had this problem, and said if the flywheel wasn't balanced that I'd be hearing it only while engaging. He thinks that either the clutch disk or pressure plate have a defect. I could see it being the pressure plate because it's not the same as the disc itself. When I ordered the kit I purchased the cheapest OEM Exedy one I could find, well this kit was the cheapest because the pilot/throwout and pressure plate were Valeo while only the disc was Exedy. I didn't have time to send it back and figured Valeo wasn't the worst brand it could be so I just installed it.

I think I'm going to buy a new clutch kit and flywheel. Thoughts?

holmesnmanny

Ive never heard of anyone having issues with an Exedy clutch kit. Im running an Exedy clutch kit with no issues but i forget which flywheel i had bought at the moment.

What is the clutch kit part number and where did you buy it and which flywheel did you buy?

Also are you sure its a grinding sound and not just a vibration. These are really two different noises/sounds. It would be best to know for sure.

UncleTrill814

I have an Exedy stage 2 in my civic and had an Exedy stage 2 in another Integra and had no problems. However, those were full Exedy clutch kits. As I stated above when I purchased this clutch I got it off eBay and didn't read carefully enough. ONLY the clutch disc is Exedy (KCH05 I believe) but the pressure plate is Valeo. I'm not sure if maybe the disc and plate are not working together correctly? The flywheel is CB Haus (as state above). I think it's made in Cali. This time I'm going with Exedy stage 1 and competition clutch 12lb flywheel. I'm just going to replace everything and hope that fixes it. If not I'll have to tear down the motor :/

It's a definite grinding noise that also causes a slight vibration (I also have Avid 62a motor mounts) I posted a video of the noise from the bay...

m4xwellmurd3r

All I hear is metal resonating against something. Does your exhaust rub anywhere, intake pipe, heatshields, etc?

UncleTrill814

update

Installed the CC 12lb flywheel and Exedy Stage 1 clutch. After initial startup the car idled for about 3-4 minutes in the grinding rpm range and it didn't make the noise. After some high fives with my buddies we turned it off and cleaned up. As soon as I tried to drive the car the noise came back. Unfortunately I don't have access to another vehicle anymore and I'm forced to drive the car. Same as before, engine runs fine and clutch feels great. Still an atrocious grinding noise. Hopefully it makes it through the upcoming winter... :/

slowcivic2k

The noise sounds like loose shafts that are bouncing back and forth with engine vibration. They are heavy and deep, and is definitely an internal sound due to its hollow resonance. If it were external, you would hear a clank like a heat shield on the exhaust that is loose without the hollowness.

Sounds like a bad bearing, loose shaft, no oil? Given the noise returns with a load, bearing damage is highly likely. What caused it needs to be identified.

Did you install BOTH dowel pins when reinstalling the unit? Failing to use these will result in an off-center mounting of the transmission and crankshaft. This WILL destroy the input bearing and the rear crank bearing at the least.