dschmittie1

iTrader: (64)

OK I have my friends 95 firehawk in my garage right now. it has a rattle coming from the bell housing area of the transmision at idle (big cam and high compression) it lopes and you get a rattle out of gear with the clutch released. The rattle goes away if you pick up the engine speed to smooth out the idle or if you depress the clutch pedal. I pulled the slave and the inspection cover. Can't see anything obvious. Could this just be a result of the pull type clutch setup and the lumpy idle making things rattle around? I had to of the older tech's at my shop listen to it today but they only had the same ideas as me. I am thinking this isn't really a problem but my friend wanted it checked out since he is selling the car. And this has been doing this ever since he had the clutch put in almost 3000 miles ago. but refuses to go back to the shaddy shop that put it in. Thanks

Adnectere

A bad throw-out bearing will grind if you push the pedal in. If the noise goes away when you do that, it's not the t-o bearing.

Adnectere

If it happened right after the shop put the clutch in, it sounds like it didn't get put in there correctly. A rattle is going to be something improperly mating or loose. You say it "smoothes" out though...does that mean a vibration? (Other than the lumpy cam was pre-new-clutch)

dschmittie1

iTrader: (64)

the rattle is only there at when the idle is lumpy or you olet the car lope like 800 rpm. If you pick the idle speed up to 1000-1200rpm(when the idle smooths out) it goes away. When I pulled the slave you can press on the fork that goes to the throw out bearing. and it does kinda have a little bit of play between it's full rested postion and when it starts to press against the fingures of the preasuer plate. I am wondering if it that is where the rattleing is coming from.

Adnectere

There will be a small amount of free travel/play between the point where you first press on the fork and when the throw-out bearing acts on the pressure plate. It's necessary to have a small amount of free play to ensure the clutch engages completely. If there were no free play it might be slightly unengaged (slipping), but with free play you have ensured it is engaged all the way. It would be bad if you _didn't_ have free play because then the clutch might be slipping slightly which would ruin it fast. As for the specific clutch, I don't know how much free play is necessary, but it sounds like you're saying a small amount which should be just right.

Adnectere

It sounds like not a ton of people are posting on your problem so I'll put one up of my one cent ideas of things that might be wrong:
Friction disc damper springs might be weak or broken. This will usually rattle at least when you first engage the clutch disc. It may also be a problem inside the tranny. How does it behave in neutral with the clutch disc engaged both at idle and revving to smoothness? Can you feel anything through the pedal itself? Wobbling, vibration, up/down movements, pulsation, stiffness, too much play?
The obvious with some type of vibration/rattle is a misalignment of moving parts. The housing could be off, the flywheel might be loose,etc. You said it started with clutch replacement so it's something involving that (the cam went in before the clutch and everything was good with the new cam & old clutch, right?)

dschmittie1

iTrader: (64)

The clutch is a RAM not sure of specific modle. The car drives fine goes into all gears smoothly, clutch engagement is nice. Really not that many miles on the clutch around 3000.
The rattle is only there in neutral (out of gear) with the clutch pedal released (clutch engaged) once you apply any preasure to the clutch pedal the rattle goes away or if you pick up the rpm's to smooth out the ruff idle.
As far as where it is coming from I am fairly certian that it is NOT coming from inside the transmission. Using a poor man's mechanic Stethoscope (long screw driver) I know that the niose is coming from the bell housing area. So this limits the problem area to TO bearing, piloet bearing, clutch itself or input shaft bearing.

Yes everything else was done to the car before this clutch was installed after a spec took a dump at a pretty low milage.

I am not sure as to how long this rattle has been there he had this clutch put in before I got to know him otherwise I would have done it. But the rattle has been there for as long as I have known him. But he told me he thinks the rattle started after this clutch was installed

I have visually inspected everything I can with out removing the tranny. I love inspection covers. things look good. I guess I will see what happens when I start it up again.

Adnectere

Your culprit sounds like the input shaft bearing. If the noise is only in neutral with the clutch/PP engaged, that's telltale ISB. The input shaft is still spinning, but once you stop it from spinning via engaging the clutch pedal, it stops and hence the noise.

calhoon

iTrader: (6)

Clutches are "tuned" to the engine with the calibration of the "neutral" stage . Thats the spring pack at the center of the disc. This is done for production parts. Aftermarket clutch makers do not take the expense or time to tune. Also because they manufacture for multiple applications tuning would be vague at best.
You have an aftermarket clutch and an altered engine that produces a rough idle. The fact that it is diminished with RPM should tell you that it lacks the "tune" of the clutch. I would not worry about the rattle as it is mostly an anoiyance thing . I think the only way to address this is to raise the idle speed to trim out/ lessen the affects of the pulses.

dschmittie1

iTrader: (64)

I figured as much. unfortunatly I can't set the idle any higher with out tuning getting the car tuned(set screw is out the whole way). It does bother the owner he just wanted it checked out before he sells it. Thanks for the input.