Fidanza users

[9T1 Red ZR1]

I have a question for anyone using the Fidanza flywheel. I get a slight vibration/rattle from my transmission in only 5th or 6th gear when the RPMs are between about 1500 to 2000. Once above about 2000 rpm, it goes away and in any other gear in that RPM range, there is no vibration. I have C-beam plates and the torque is correct on them. Is this something anyone else has? Suggestions if it shouldn't be happening?


Thanks,
Bill

[XfireZ51]

I have a question for anyone using the Fidanza flywheel. I get a slight vibration/rattle from my transmission in only 5th or 6th gear when the RPMs are between about 1500 to 2000. Once above about 2000 rpm, it goes away and in any other gear in that RPM range, there is no vibration. I have C-beam plates and the torque is correct on them. Is this something anyone else has? Suggestions if it shouldn't be happening?


Thanks,
Bill

No I don’t get any vibration at any time other than stopped in neutral.
What trans fluid are using?
Is this happening at steady cruise or during accel/decel?

[mgbrv8]

I don't get vibration just a noise(slight rattle) at idle because the dual mass isn't there to dampen it out anymore

Dave

[9T1 Red ZR1]

I am using the Amsoil fluid in the transmission. It only happens when accelerating. it goes away as soon as I let off of the gas. It's funny, there is almost no rattle at idle in neutral. I forgot to mention, I have the Hurst shifter.

[Paul Workman]

I am using the Amsoil fluid in the transmission. It only happens when accelerating. it goes away as soon as I let off of the gas. It's funny, there is almost no rattle at idle in neutral. I forgot to mention, I have the Hurst shifter.

We've both got Fidanza FWs in our Zs. Like Dom, except for idling in neutral, no rattling at any speed/load condition.

You mentioned a Hurst shifter. Tho completely different from a ZF shifter, but THAT or something related to the shifter sounds very similar to what I experienced with a shifter on a '69 SS Malibu: worn bushings rattled under heavy loads. Furthermore, it sounds like there is a resonant frequency - more evidence of something loose (but pretty sure it's NOT the FW). I think I'd look at the shifter and the C-beam bolts/plates first.

[9T1 Red ZR1]

Thanks for the replies. I will look into the items you suggested.


Bill

[XfireZ51]

BTW, I have a Hurst shifter and Intake/Exhaust cams.

[Vette73]

I get the typical noise up until around 2,300 RPM......Sometimes it sounds like an electric saw as I am accelerating......In sixth gear at the RPM you specified,it sounds like a motor boat......I just leave it in fifth for that matter if I'm doing 60-65....

Car has obx headers and exhaust .....Car is fully ported with intake cams...

Sent from my LG-TP260 using ZR-1 Net Registry mobile app (http://r.tapatalk.com/byo?rid=90383)

[XfireZ51]

I get the typical noise up until around 2,300 RPM......Sometimes it sounds like an electric saw as I am accelerating......In sixth gear at the RPM you specified,it sounds like a motor boat......I just leave it in fifth for that matter if I'm doing 60-65....

Car has obx headers and exhaust .....Car is fully ported with intake cams...

Sent from my LG-TP260 using ZR-1 Net Registry mobile app (http://r.tapatalk.com/byo?rid=90383)

Are u describing the Fidanza or exhaust drone?

[Vette73]

Are u describing the Fidanza or exhaust drone?
The fidanza I have noise until like 2,300 RPM,after that it goes away.......Sixth gear is def. the exhaust drone....

Sent from my LG-TP260 using ZR-1 Net Registry mobile app (http://r.tapatalk.com/byo?rid=90383)

[XfireZ51]

The fidanza I have noise until like 2,300 RPM,after that it goes away.......Sixth gear is def. the exhaust drone....

Sent from my LG-TP260 using ZR-1 Net Registry mobile app (http://r.tapatalk.com/byo?rid=90383)

FW noise up thru 2300rpm doesn’t sound right IMO.

[Vette73]

FW noise up thru 2300rpm doesn’t sound right IMO.
Yeah Dempsey installed it when he ported the heads and did the cams...

I wouldn't say its a steady noise up until 2,300 rpm.....Its more likes a few seconds up until 2,300.......Noise sounds like a saw cutting.......

Demps said its the " usual " single mass flywheel noise........Would be curious to see how other cars reacted to the fidanza.....Drove a 95 for a short distance over a year ago w a fidanza....Don't remember being as noisy as mine though......Mines a 91....

Sent from my LG-TP260 using ZR-1 Net Registry mobile app (http://r.tapatalk.com/byo?rid=90383)

[Ccmano]

Yeah Dempsey installed it when he ported the heads and did the cams...

I wouldn't say its a steady noise up until 2,300 rpm.....Its more likes a few seconds up until 2,300.......Noise sounds like a saw cutting.......

Demps said its the " usual " single mass flywheel noise........Would be curious to see how other cars reacted to the fidanza.....Drove a 95 for a short distance over a year ago w a fidanza....Don't remember being as noisy as mine though......Mines a 91....

Sent from my LG-TP260 using ZR-1 Net Registry mobile app (http://r.tapatalk.com/byo?rid=90383)

How many miles on your car? The black label ZF trans tends to have grindy whine to it in low gears on acceleration. Anything beyond that and I would think an input shaft bearing is suspect.
H
:cheers:

[9T1 Red ZR1]

Dempsey did mine as well as part of the DH350 package. The electric saw sound is a good description. Most noticeable if I touch the gas in 5th or 6th, I have the sound, it immediately stops when I take my foot off the gas. I will follow Paul's advice about resonance and look for something loose or maybe the exhaust touching something.


Thanks,
Bill

[Vette73]

How many miles on your car? The black label ZF trans tends to have grindy whine to it in low gears on acceleration. Anything beyond that and I would think an input shaft bearing is suspect.
H
:cheers:
47,100 miles....

Sent from my LG-TP260 using ZR-1 Net Registry mobile app (http://r.tapatalk.com/byo?rid=90383)

[Vette73]

Dempsey did mine as well as part of the DH350 package. The electric saw sound is a good description. Most noticeable if I touch the gas in 5th or 6th, I have the sound, it immediately stops when I take my foot off the gas. I will follow Paul's advice about resonance and look for something loose or maybe the exhaust touching something.


Thanks,
Bill
Yes....It can be a little annoying but I'm guessing each car is somewhat different.....I'm basically getting used to it.......The faster you spin the RPMs up,the faster it goes away.....

Sent from my LG-TP260 using ZR-1 Net Registry mobile app (http://r.tapatalk.com/byo?rid=90383)

[XfireZ51]

Yes....It can be a little annoying but I'm guessing each car is somewhat different.....I'm basically getting used to it.......The faster you spin the RPMs up,the faster it goes away.....

Sent from my LG-TP260 using ZR-1 Net Registry mobile app (http://r.tapatalk.com/byo?rid=90383)

Forgive me but I don’t think you should be “getting used to it”. Unfortunate u guys aren’t closer to the Windy City. Take a ride sometime.

[A26B]

Have you inspected the u-joints.... all 6 of them?

[9T1 Red ZR1]

I have not. I removed the exhaust hangers in the middle and by the differential to see if the exhaust is hitting anything, but that didn't help. Forgive my question, how do I check the U joints? Would they be suspect if the buzzing seems to be RPM related rather than speed related?

Thanks,
Bill

[A26B]

I have not. I removed the exhaust hangers in the middle and by the differential to see if the exhaust is hitting anything, but that didn't help. Forgive my question, how do I check the U joints? Would they be suspect if the buzzing seems to be RPM related rather than speed related?

Thanks,
Bill

For really worn joints.
Trans in neutral, Rotate the drive/half shaft by hand, back & forth, CW to CCW & look for movement of u-joint in the yokes. Do not confuse with driveline slack which is normal.

Best check involves some labor. If in doubt, remove drive shaft. remove caps from rear joint. Dry & dusty = bad. Replace both ft & rear. Same thing with half shafts

[9T1 Red ZR1]

Thank you for your instructions. This site always has helpful people willing to share knowledge! I will check the U joints just to be sure they are OK.

Before I read your response, I sent an email to Bill at ZFDoc, he said it sounds like a solid hub clutch disc was used. The result is hearing a gear rattle which he feels is harmless.

Thanks to everyone for your replies.

Bill

[XfireZ51]

I think your Fidanza was installed without a sprung hub clutch disk.

[Dynomite]

For really worn joints.
Trans in neutral, Rotate the drive/half shaft by hand, back & forth, CW to CCW & look for movement of u-joint in the yokes. Do not confuse with driveline slack which is normal.

Best check involves some labor. If in doubt, remove drive shaft. remove caps from rear joint. Dry & dusty = bad. Replace both ft & rear. Same thing with half shafts

Dry and dusty....that is SHOT.....not just bad :p

If I were going so far as to remove drive shaft to CHECK U-Joints I would just replace U-Joints when I have drive shaft removed......there is more work removing C-Beam and Drive Shaft than work replacing U-Joints with Drive shaft on bench :D

I replaced U-Joints on my 95' as I noticed just a tad of play pushing on the U-Joint side to side. Rotate Drive Shaft just a bit in Neutral as Jerry suggests and Push Side to Side on the U-Joints......then rotate drive shaft some more and push again. If the U-Joint seems solid then you should be fine.

See Item #3 Rebuilt Black Label Transmission Installed and New Driveshaft U-Joints (https://www.corvetteforum.com/forums/c4-zr-1-discussion/3005470-tech-info-lt5-modifications-rebuild-tricks-500-hp-13.html#post1592505462)

[jss06c6]

I believe Bill B. Is on track if you don't have a sprung hub disc in your setup.. Fidanza is a bit noisy at idle with clutch engaged in neutral, but should be stone quiet when loaded and running through the gears..

Sent from my QTAIR7 using ZR-1 Net Registry mobile app (http://r.tapatalk.com/byo?rid=90383)

[Flyman 27]

My fidanza is noisy. At idle it almost knocks as loud as an engine bearing failing.
If I lug the engine down in any gear it makes the trans quite noisy as well. Higher rpms are fine.

[XfireZ51]

My fidanza is noisy. At idle it almost knocks as loud as an engine bearing failing.
If I lug the engine down in any gear it makes the trans quite noisy as well. Higher rpms are fine.

May want to check w Marc to see what clutch disk was specified for that Haibeck 500 package.

[Ccmano]

Interesting... so I just installed a brand new ZF blue label trans (lucky find, thanks Blackwidow#2) last Saturday. I have a Fidanza FW, new McLoed sprung hub organic disc, low mile Valeo ZR-1 spec PP, new fluted GM pilot bearing, new Centerforce throw out bearing (because of the blue label). Also have new driveshaft Moog u joints and new C Beam Plates from Bill B. The trans is flawless, smooth, tight and nice shifting. Used Castrol Edge 10-60 oil a prescribed in the trans.

I get moderate gear rattle at idle with the clutch out, less than with the old trans but still there with the idle bumped to 850. Stone quiet with the clutch pedal in. This was expected.

As with the old trans I still get what was previously noted in this thread by others as the electric (Skill) saw metallic sound on acceleration, at lower rpms, most noticeable in the low gears but also in the high gears, again only in the lower rpm ranges. Certainly there when lugging the engine. Also interesting is that when cold it is bearly noticeable. After about a half hour of driving or about 30 miles, when everything heats up, it becomes much louder.

From what I read here some cars with Fidanzas seem to have this and others not. I have OBX headers and exhaust. Heat shields have been removed, so some sort of external resonance is unlikely.

I would luv to get to the bottom of this. My (educated) speculation is as follows...... It is obviously some sort of high frequency vibration of a metallic nature. Since both trans’ exhibited this noise with the Fidanza I’m inclined to rule out the TO bearing. The old trans had a new old stock AC/Delco unit and the new trans has the centerforce. Btw the fit of the centerforce to the input shaft was much better than the Delco. That leaves us with the Fidanza itself. We could actually be hearing a ringing of sorts from the Flywheel? The disc is a possibility, depending on the MFG and construction of the hub, we could be hearing the vibration of the hub under load. The PP seems less likely. Most use the original Valeo, some have the noise and some don’t. The trans itself is a possibly but since my ultra high mile trans and the brand new one both exhibit the same noise I’m less inclined to think it’s a trans issue, tho still possible. Of course the interaction of the components is always a possibility too. As we know stacking of tolerances (positive and negative) can be a big issue.

Not sure if I can live with the noise at this point and may put the DM back in. But I will give it a try for a while.

I would be interested in the collective thoughts on the is matter. As in all things mechanical there is certainly a solution, we just have to find the source.
H
:cheers:

[XfireZ51]

I originally used an OEM LT1 Camaro clutch. Sprung hub. Now using a Centerforce sprung hub. No noise as described using a black tag ZF. Brass pilot bearing. I switched from the BMW Castrol to Amsoil. No difference in either. Each exhibits more rattle at idle the hotter trans fluid gets. I’d love tk listen to this.

[9T1 Red ZR1]

I am planning to pull the transmission this weekend and install the Centerforce sprung disc. I am also going to ship the trans to Bill at ZFDoc and have him work his magic on it. I will post the results in a few weeks.


Thanks,
Bill

[Flyman 27]

May want to check w Marc to see what clutch disk was specified for that Haibeck 500 package.

It is my plan to have Mark swap out my clutch/flywheel asm for a DM unit in the spring. The drive-ability and quiet operation is more important to me than a little quicker revving. Just personal choice.
Right now I am just trying to locate DM clutch asm parts that I can afford. In the first several months I had to put way more money into the Z than anticipated, now I am low budget for awhile.

Dan

[Jagdpanzer]

Are you using the same bellhousing? Could be it is introducing some misalignment which is putting side load on the input shaft bearing that is causing the noise you mentioned.


Sent from my iPhone using ZR-1 Net Registry (http://r.tapatalk.com/byo?rid=90383)

[Flyman 27]

Mark installed the clutch asm as part of his "500" package so I am confident everything is to spec.
If I depress the clutch pedal to the floor a lot of the noise goes away. The trans is real noisy if I lug the engine down any at all, especially in the higher gears. Mid to high rpm's everything is fine.
Some guys don't mind the noise at all, but I like to listen to the exhaust most of the time. The noise drives me crazy, plus I really dislike having to explain to all I show the car to that it really isn't about to blow up, it's just clutch/flywheel noise....

[XfireZ51]

I sort of think its fun to pull up to some ricer Subie or Mitsu or even a C6 with a car that sounds like its ready to blow up. And then...BAM! Talk about sleeper.
:dancing:dancing

[Flyman 27]

I sort of think its fun to pull up to some ricer Subie or Mitsu or even a C6 with a car that sounds like its ready to blow up. And then...BAM! Talk about sleeper.
:dancing:dancing

I had not thought of that, that's a good point.

My clutch works fine, it is just the noise that bothers me. It could very well mislead some unwitting victims of the beast!

[XfireZ51]

I had not thought of that, that's a good point.

My clutch works fine, it is just the noise that bothers me. It could very well mislead some unwitting victims of the beast!


Yeah who would ever suspect a POS C4 Corvette that sounds like a rattle can.

BTW, maybe once the snow clears out maybe we can take a listen to your ZR.

[GOLDCYLON]

While I miss the power... I parted ways with the Fidanza a year ago. The rattle drove me nuts. I put up with it for about 7 years. The unit I had pulled out was beat to hell. The ZF.Doc returned to stock and I haven't looked back since. Remember my 91 is my DD and my 90 is my Monday and maybe weekend driver only so the 91 has significantly more beating on it.


GC

[GOLDCYLON]

Mark installed the clutch asm as part of his "500" package so I am confident everything is to spec.
If I depress the clutch pedal to the floor a lot of the noise goes away. The trans is real noisy if I lug the engine down any at all, especially in the higher gears. Mid to high rpm's everything is fine.
Some guys don't mind the noise at all, but I like to listen to the exhaust most of the time. The noise drives me crazy, plus I really dislike having to explain to all I show the car to that it really isn't about to blow up, it's just clutch/flywheel noise....



Or the timing chains rattle upon start up for 3 seconds that sound like the engine is coming apart noise as another LT5ism. GC

[Ccmano]

Are you using the same bellhousing? Could be it is introducing some misalignment which is putting side load on the input shaft bearing that is causing the noise you mentioned.


Sent from my iPhone using ZR-1 Net Registry (http://r.tapatalk.com/byo?rid=90383)

Same bellhousing. Checked the surfaces before reassembly and didn’t see anything. Checked the alignment of the trans and c-beam to the tunnel upon assembly with the measuring sticks provided by Bill B in the Beam Plate kit. While the measurements were not perfect they were very close. As you know once everything except the c-Beam is bolted together adjustment is very limited. I may go back and see if I can get those specs closer.
H
:cheers:

[Jagdpanzer]

Next time you have the transmission out wouldn’t hurt to check the mounting flange bore and face runout with a dial indicator on both the transmission and bell housing.
A while back I was tracking down an unusual whining noise a ZF transmission was making in the lower gear ranges. This particular transmission came out of a wrecked ZR-1 that had 5K miles. Found one of the bolting ears on the main case to be slightly bent that introduced an angular misalignment on the input shaft which caused the input shaft bearing to whine. Machined the ear to correct the angular misalignment solved the whining noise problem.

[Vette73]

My question is has anybody went from a stock clutch disk to a sprung hub disc and noticed the difference in sound? I have a fidanza on my car now with all the stock clutch components....Noise is more prevalent in the low RPMS and of course if I'm lugging it around town...Getting used to the noise though , than again, its cold in the northeast....Driving with the Windows closed....Will see, when the top comes off and the Windows go down,I will see if I can tolerate it....

Cheers.....

Sent from my LG-TP260 using ZR-1 Net Registry mobile app (http://r.tapatalk.com/byo?rid=90383)

[Ccmano]

Next time you have the transmission out wouldn’t hurt to check the mounting flange bore and face runout with a dial indicator on both the transmission and bell housing.
A while back I was tracking down an unusual whining noise a ZF transmission was making in the lower gear ranges. This particular transmission came out of a wrecked ZR-1 that had 5K miles. Found one of the bolting ears on the main case to be slightly bent that introduced an angular misalignment on the input shaft which caused the input shaft bearing to whine. Machined the ear to correct the angular misalignment solved the whining noise problem.

Interesting thought Phil. Considering both transmissions exhibited the same sound, in your scenario it might be more likely that the bellhousing is off. I will try that next time.
H
:cheers:

[GOLDCYLON]

Next time you have the transmission out wouldn’t hurt to check the mounting flange bore and face runout with a dial indicator on both the transmission and bell housing.
A while back I was tracking down an unusual whining noise a ZF transmission was making in the lower gear ranges. This particular transmission came out of a wrecked ZR-1 that had 5K miles. Found one of the bolting ears on the main case to be slightly bent that introduced an angular misalignment on the input shaft which caused the input shaft bearing to whine. Machined the ear to correct the angular misalignment solved the whining noise problem.

I just read this Phil. When you said the word "machined" if anybody else said that statement I would assumed it was a truely involved process which would have Been a tad amount to swinging a large hammer. However I'm sure you actually did do as stated based upon your skillset. You must have the ultimate set of tools. Well done. GC

[efnfast]

You mention Hurst shifter. My shift knob, the nutsert was not tight in the plastic ball and it buzzed? rattled? buzz sawed? I replaced it. It made me drive around with my hand on the shifter which is not good practice, to keep it quite.

[jss06c6]

Same bellhousing. Checked the surfaces before reassembly and didn’t see anything. Checked the alignment of the trans and c-beam to the tunnel upon assembly with the measuring sticks provided by Bill B in the Beam Plate kit. While the measurements were not perfect they were very close. As you know once everything except the c-Beam is bolted together adjustment is very limited. I may go back and see if I can get those specs closer.
H
:cheers:
Hmm.. other than normal gear rattle with clutch engaged in neutral, the Fidanza was stone quiet even before Bill rebuilt my trans. Concerning to me that the tolerances would be so critical. I pulled the bronze pilot bushing and other than being driven in a bit eccentric, it was good. You should not be getting any noticeable noise or rattle other than neutral and clutch engaged..

I've got the spring hub disc if you want it. Happy to ship to you on my nickel..

Steve

Sent from my XT1585 using ZR-1 Net Registry mobile app (http://r.tapatalk.com/byo?rid=90383)

[Jagdpanzer]

I just read this Phil. When you said the word "machined" if anybody else said that statement I would assumed it was a truely involved process which would have Been a tad amount to swinging a large hammer. However I'm sure you actually did do as stated based upon your skillset. You must have the ultimate set of tools. Well done. GC



Luckily l have a buddy with a nice Bridgeport mill with a table large enough to set up a ZF transmission


Sent from my iPhone using ZR-1 Net Registry (http://r.tapatalk.com/byo?rid=90383)

[GOLDCYLON]

Luckily l have a buddy with a nice Bridgeport mill with a table large enough to set up a ZF transmission


Sent from my iPhone using ZR-1 Net Registry (http://r.tapatalk.com/byo?rid=90383)

I have friends that help me out from time to time as well. GC

[Ccmano]

Hmm.. other than normal gear rattle with clutch engaged in neutral, the Fidanza was stone quiet even before Bill rebuilt my trans. Concerning to me that the tolerances would be so critical. I pulled the bronze pilot bushing and other than being driven in a bit eccentric, it was good. You should not be getting any noticeable noise or rattle other than neutral and clutch engaged..

I've got the spring hub disc if you want it. Happy to ship to you on my nickel..

Steve

Sent from my XT1585 using ZR-1 Net Registry mobile app (http://r.tapatalk.com/byo?rid=90383)

Thanks, I will take you up on that!

So what do we know, at least with my setup. The Fidanza was quiet when you had it and now the same FW in my car and we have noise. That should rule out the flywheel. I’ve installed it with two different transmissions and Throwout bearings. Noise with both setups. That should rule out the trans and the TO bearing. I’m using your PP. You had no noise. That should rule out the PP. So that leaves the disc, a tolerance stacking situation or an alignment problem as Phil pointed out. We might be getting somewhere here. Starting to look like there’s another trans pull in my future.

Of note was when I pulled the old pilot bearing out. It was a needle bearing type, so likely already a replacement. What was unusual was that it was sitting slightly crooked in the crank recess. I measured the degree of variation and found it was off by 0.0235in from high to low point. At the time I thought it was simply worn out. Now I’m wondering if it wasn’t an indication of misalignment.

Looks like I’ll be going back in....

H
:cheers:

[jss06c6]

If the needle bearing was an issue, I'd expect you would see wear on the pilot shaft, but you've changed transmissions and no change, so nix that thought.. I'll get the clutch disc out to you today Hans.. something's off here (pun not intended!) and we sure need to isolate it..

Sent from my XT1585 using ZR-1 Net Registry mobile app (http://r.tapatalk.com/byo?rid=90383)

[Paul Workman]

Interesting... so I just installed a brand new ZF blue label trans (lucky find, thanks Blackwidow#2) last Saturday. I have a Fidanza FW, new McLoed sprung hub organic disc, low mile Valeo ZR-1 spec PP, new fluted GM pilot bearing, new Centerforce throw out bearing (because of the blue label). Also have new driveshaft Moog u joints and new C Beam Plates from Bill B. The trans is flawless, smooth, tight and nice shifting. Used Castrol Edge 10-60 oil a prescribed in the trans.

I get moderate gear rattle at idle with the clutch out, less than with the old trans but still there with the idle bumped to 850. Stone quiet with the clutch pedal in. This was expected.

As with the old trans I still get what was previously noted in this thread by others as the electric (Skill) saw metallic sound on acceleration, at lower rpms, most noticeable in the low gears but also in the high gears, again only in the lower rpm ranges. Certainly there when lugging the engine. Also interesting is that when cold it is bearly noticeable. After about a half hour of driving or about 30 miles, when everything heats up, it becomes much louder.

From what I read here some cars with Fidanzas seem to have this and others not. I have OBX headers and exhaust. Heat shields have been removed, so some sort of external resonance is unlikely.

I would luv to get to the bottom of this. My (educated) speculation is as follows...... It is obviously some sort of high frequency vibration of a metallic nature. Since both trans’ exhibited this noise with the Fidanza I’m inclined to rule out the TO bearing. The old trans had a new old stock AC/Delco unit and the new trans has the centerforce. Btw the fit of the centerforce to the input shaft was much better than the Delco. That leaves us with the Fidanza itself. We could actually be hearing a ringing of sorts from the Flywheel? The disc is a possibility, depending on the MFG and construction of the hub, we could be hearing the vibration of the hub under load. The PP seems less likely. Most use the original Valeo, some have the noise and some don’t. The trans itself is a possibly but since my ultra high mile trans and the brand new one both exhibit the same noise I’m less inclined to think it’s a trans issue, tho still possible. Of course the interaction of the components is always a possibility too. As we know stacking of tolerances (positive and negative) can be a big issue.

Not sure if I can live with the noise at this point and may put the DM back in. But I will give it a try for a while.

I would be interested in the collective thoughts on the is matter. As in all things mechanical there is certainly a solution, we just have to find the source.
H
:cheers:

Setup:

Fidanza FW (new when installed)
Centerforce sprung hub organic disc (Camaro)
Needle bearing type pilot bushing
Veleo ZR-1 pressure plate (PP ARP bolts = 1/4"+ longer; drilled and tapped FW for longer bolts)
"AutoZone" TO bearing (New w/ PP installed, ~ 21k miles ago)
Driveline balanced (FW, main drive shaft w/ yoke w/ new Spicer U-joints)
Redline High Shock fully synthetic gear oil (replacing former BMW Castrol)
Black Tag ZF (stock) and stock shifter
Idle set to 850, LT5 = stock cams.

When drivetrain is cold, there is no rattle (neutral w/ clutch engaged)
When drivetrain is fully warmed up, there is some gear rattle
Gear whine is just perceptible in 1st gear, but exhaust/road noise drowns out any further (black tag type) gear noise in higher gears.

In contrast, Ami's Z has Pete's cams. Idle is set at 850, but has noticeable rattle when driveline is cold, but noise becomes worse.

Both cars have just perceptible gear whine when cruising in 6th gear.

I posted this video of my car as a reference - as I'm :icon_scra by the experiences some of y'all are reporting.

This is the only video I have of the car idling, configured as noted (above). Temp was in the teens. Gear rattle is non-existent.

Note: The engine was fully up to temp, but the the driveline was cold (teens ºF) as the car was allowed to idle (i.e., NOT driven first).

https://www.youtube.com/watch?v=y1YFa8ruh8A

[XfireZ51]

My Fidanza setup is made up of:

1. Stock TO bearing
2. Valeo PP
3. Centerforce Sprung Hub LT1 disk. Prior to that, OEM Camaro sprung hub.
4. Brass pilot bearing
5. Amsoil Manual Trans Synchro fluid
6. Hurst short throw shifter
7. A custom tune which I believe mitigates the rattle. Smoother idle and running minimize the gear rattle.
My motor has Dr. Greekenstein’s Intake and Exhaust cams.
Idle is ~ 925rpm. No rattle w cold trans. Gear rattle is there in Neutral. Loudness depends on how hot trans fluid is. No rattle or whine in any gear including 6th gear and lower rpms (12-1300rpm).

[Ccmano]

If the needle bearing was an issue, I'd expect you would see wear on the pilot shaft, but you've changed transmissions and no change, so nix that thought.. I'll get the clutch disc out to you today Hans.. something's off here (pun not intended!) and we sure need to isolate it..

Sent from my XT1585 using ZR-1 Net Registry mobile app (http://r.tapatalk.com/byo?rid=90383)

I appreciate your help Steve. If it was only the rattle at idle it would not bother me. But this grindy metallic shearing noise or Skill saw noise as some describe it at low rpm acceleration or load, particularly when hot, concerns me. Apparently some installers even consider it normal. At least I don’t appear to be alone. It will be a few weeks before I can pull it apart again.
H
:cheers:

[XfireZ51]

I gotta think Marc H is going to weigh in on this. How many of Fidanza owners
are using needle bearing pilot bearing or brass?
Did the buzzsaw noise gradually develop, or did it appear immediately after FW install?

[Ccmano]

I gotta think Marc H is going to weigh in on this. How many of Fidanza owners
are using needle bearing pilot bearing or brass?
Did the buzzsaw noise gradually develop, or did it appear immediately after FW install?

The noise was there immediately. I really don’t think the Pilot bearing is part of the issue. Both have been used successfully with stock and light weight FW’s. Both have their advocates.

I am a bit surprised the Marc and Bill B haven’t commented. From what we hear on this thread at least the noise is not that uncommon. Nevertheless there must be a reason.
H
:cheers:

[-=Jeff=-]

Bill B is a member here?

[9T1 Red ZR1]

I got my transmission back from Bill (ZFDoc) and installed it along with the new Centerforce sprung clutch disc. I still have the Fidanza light weight flywheel. Bill installed one of his short throw shifters and refurbished the transmission. I installed everything and am happy to say my gear noise in 5th and 6th gear is gone. No rattles or noises and it shifts great. Bill did a fantastic job and the ZR-1 drives great. =D>

Bill

[Vette73]

Hey Bill
You got the Dragon heart package from Dempsey correct? I remember seeing your car there when I dropped mine off awhile ago....

I'm going to try the sprung hub disc with my fidanza..It totally slipped my mind when Dempsey did the build..If I can eliminate the skill saw noise upon acceleration depending on the rpm, that will be a good thing...However, I am used to it by now since the car is only used for sport...

Just curious , did your tranny need refurbishing or you just decided to do it?

[XfireZ51]

Honestly, there should be no rattle from the single mass FW setup once in any gear.

[Ccmano]

I have two LT5 engines sitting in my garage right now. My old one (high miles) where the Fidanza, a brand new transmission and a sprung hub clutch caused considerable skill saw noise and the newer low mile one that has a Fidanza and a solid hub clutch that apparently had no noise. Some have theorized that the drain tube interfering with the flywheel could cause it. I see no signs of direct interference on either. I do note that the drain tube sits loosely against the oil pan on the old engine and tightly on the newer engine. I am theorizing the possibility that vibration set up by the flywheel gets the tube to vibrate against the pan generating the noise. If I vibrate the tube manually against the pan the noise emitted seems to be at a similar frequency. When I reassemble the new engine/ trans along with the sprung hub clutch I plan to either remove the tube altogether (most likely) or adjust the tube so that it does no contact the pan or block at any point. My mix of old and new parts will still not definitively answer the question once it’s back together.

What would be interesting is if some with this issue could get under their car and simply insulate the tube from the pan to see if it has an impact. I believe the bottom of the tube where it touches the pan is accessible from under the car.
H
:cheers:

[9T1 Red ZR1]

Vette73
Dempsey did do the Dragonheart package for me. It runs and looks awesome.

I wanted to have the transmission checked while I had it out. Bill did find some damage to 4th gear and the 4th gear synchro. I know he changed the shims to get an optimum set up. Hopefully, just the clutch will work for you.

Bill

[Vette73]

I have two LT5 engines sitting in my garage right now. My old one (high miles) where the Fidanza, a brand new transmission and a sprung hub clutch caused considerable skill saw noise and the newer low mile one that has a Fidanza and a solid hub clutch that apparently had no noise. Some have theorized that the drain tube interfering with the flywheel could cause it. I see no signs of direct interference on either. I do note that the drain tube sits loosely against the oil pan on the old engine and tightly on the newer engine. I am theorizing the possibility that vibration set up by the flywheel gets the tube to vibrate against the pan generating the noise. If I vibrate the tube manually against the pan the noise emitted seems to be at a similar frequency. When I reassemble the new engine/ trans along with the sprung hub clutch I plan to either remove the tube altogether (most likely) or adjust the tube so that it does no contact the pan or block at any point. My mix of old and new parts will still not definitively answer the question once it’s back together.

What would be interesting is if some with this issue could get under their car and simply insulate the tube from the pan to see if it has an impact. I believe the bottom of the tube where it touches the pan is accessible from under the car.
H
:cheers:

Interesting.....You have Johnny 5s engine I believe...I spoke to him the day after Jim installed his fidanza...He did like the performance but he did say it was noisy..

Day after that I believe he got into the accident....I have that skill saw noise in my car.....Maybe it is something else....Before I do decide to install a sprung hub disc Which I don't know how to do) I will check what you suggested...
Thnx...

[Jagdpanzer]

Also had the skill saw noise with an aluminum flywheel install.
Valley drain tube making contact with the front side of the flywheel.
http://i540.photobucket.com/albums/gg333/pwasinger/FWRub1_zps1827de7b.jpg

[oricale]

With the fidanza's I have installed, we have always had the rattle at idle. We have been working on something with fidanza to assist in the rattle without losing the performance factor. I do want to note a few things.

*The very nature of a non cammed/ cammed(esp) LT5 with a single mass flywheel is that it will rattle. Its one of the reasons GM used a dual mass with the robust Truck trans (ZF-series). However the extent if the rattle is different.
* Balancing is KEY with replacing the flywheel and clutch systems before installation(vibration ranges from about 2000-3800RPM)
* Phils advice in checking mating surfaces is SPOT ON, as we have found issues with mating surfaces, although it always caused a whine throughout the gears.
* My personal experience with rattle in the first 1800 RPM has been sparatic. I have had 2 91's do it slightly and a 95' that was pretty bad..(looking at my notes)
*RPM makes a trans oil/additive that apparently cuts down the racket..[emoji26]
*I do tell every customer that is interested in a aluminum flywheel to expect a bit of rattle..(esp if they are camming)
*Bill!...I am glad u were able to get the trans over to Bill B. I Would love a review of the trans after.