quote Originally posted by Alex4mula: So that's our rattling?

Evidently.

They don't all rattle but,

Come to our Open House & I'll show you which shifter for ring is rattling on my cutaway G6 transmission.

Archie

[This message has been edited by Archie (edited 08-21-2008).]

quote Originally posted by CBulen: I talked to the only trans parts supplier in my area to get recommendations on clutch specialists in my area, and I talked to the 2 best ones. Neither can build a clutch for me, so I am planning on using Clutchnet or Spec (spec has already told me they can do this clutch, but its waaaaaaaaay expensive). Anyway, Joseph, I am trying to understand what you are saying. Its my understanding that free play is the distance between the Diaphragm fingers and the contact face of the TO bearing, when the clutch pedals is disengaged. The info I found on the web says this shoud be about .06 to .13 inches. However, since the F40 TO bearing pushes out and contacts the fingers full time, even when the clutch pedal is disengaged, it seems to me that there would be no free play. Instead there would be some of the total travel of the TO bearing being used. In theory, if a clutch disk never wore down in thickness, I could install the flywheel far enough into the bellhousing that the TO bearing would be fully compressed while in the clutch fully disengaged condition. But because in the Real World, disks decrease in thickness over time (as well as the friction surfaces of the PP and flywheel), I should not fully compress the TO bearing when I put everything together, as the diaphram fingers will extend futhur out of the clutch cover over time, so I need to account for wear. I am pretty sure my flywheel will need a spacer between it and the crank flange, so that the clutch disk hub splines will be engaged over thier full length, on the input shaft. Right now, I don't have a clutch disk that I can use for this (the Porshe disk has a HUGE rubber hub that will not fit under a regular push type clutch cover). Is this what you mean ?

With everything bolted up, you should have "X" amount of depth for the throwout bearing to be pushed away from the diaphragm release flanges eventhough it will be touching them. In other words with the assembly together you should have enough travel room left inside the hydraulic bearing to fit a feeler gauge of the prescribed clearance thickness between the bearing and the diaphragm contact surfaces.

I used an original G6 clutch disk and took it to the local clutch builder and had it rebuilt with Kevlar the same day. Not sure what the problem is with the builders on your end but my builder gave me options aside from the stock disc including a solid hub and also located a hub in his catalog that could have been ordered overnight for a completely new disc build like the OE unit. You should avoid spacers if at all possible.

quote Originally posted by jscott1: So that explains it!

The dual mass flywheel can be very noisy and the explanation regarding its development partly to suppress noise due to complaints might be mixed up a little given a 6 spd V6 Caddilac CTS I rescently drove had the same occasional clacking noise that get from my dual mass flywheel that really gets loud and consistent when the engine is about to stall at idle. I don't believe it's all from the tranny gears as there is quite a bit of independent rotation between the flywheel halfs.

[This message has been edited by Joseph Upson (edited 08-21-2008).]

quote Originally posted by Archie: They don't all rattle but, Come to our Open House & I'll show you which shifter for ring is rattling on my cutaway G6 transmission. Archie

Is there a way to quiet it down?

Right now I'm looking at three options

1) learn to live with it

2) install another F40 and hope it's better,

3) Fix the one I have somehow to make it quieter.

I'd prefer to fix the one I have.

quote Originally posted by jscott1: Is there a way to quiet it down? Right now I'm looking at three options 1) learn to live with it 2) install another F40 and hope it's better, 3) Fix the one I have somehow to make it quieter. I'd prefer to fix the one I have.

Well, let's think about this.

If the above statement about the Dual-Mass F/W is correct, & I'm not saying it is or isn't, then GM would have to have known about the situation early enough in production that they could design the much more complex & expensive Dual-mass F/W to correct the problem.

Considering that, if there was a simple enough of a "fix" to the transmission that you & I could discover it & fix it easily, wouldn't it make more sense for them to have done that internally at GM? It would have been a lot cheaper than to design the much more complex & expensive Dual-mass F/W.

So if GM didn't figure out a fix other than the F/W.........?

So far, I've only heard the rattle on a couple of transmissions & it has been very remote on them. I do know where the rattle is coming from because I've played around with my cutaway transmission. I can assure you it's causing no damage. If you muct address uit then I'd just try another trans.

Give me a call during the day, I have an idea that you can try to prove that what your hearing is the same thing I'm talking about.

Archie

quote Originally posted by Archie: ... So far, I've only heard the rattle on a couple of transmissions & it has been very remote on them. I do know where the rattle is coming from because I've played around with my cutaway transmission. I can assure you it's causing no damage. If you muct address uit then I'd just try another trans. Give me a call during the day, I have an idea that you can try to prove that what your hearing is the same thing I'm talking about. Archie

You might be right, but mine is rattling obnoxiously loud. For everyone reading this I bought it on eBay and not from Archie, so it's not his fault. A guy that installed an eBay F40 in a Grand Am has bought another F40 on eBay and plans to replace the one he has because it rattles.
http://www.grandamgt.com/fo...owthread.php?t=73212

I think the eBay transmissions must be cheap for a reason. They are probably all rejects for some reason or another.

[This message has been edited by jscott1 (edited 08-22-2008).]

quote Originally posted by jscott1: You might be right, but mine is rattling obnoxiously loud. For everyone reading this I bought it on eBay and not from Archie, so it's not his fault. A guy that installed an eBay F40 in a Grand Am has bought another F40 on eBay and plans to replace the one he has because it rattles. http://www.grandamgt.com/fo...owthread.php?t=73212 I think the eBay transmissions must be cheap for a reason. They are probably all rejects for some reason or another.

All of the 06 trannies for the G6 are probably the same with the common factory production variations and not likely to have any associated problems with them being on Ebay as opposed to coming from somewhere else, a handful of people just happened across the surplus including a dealership and are selling them. GM may have dumped the 06 line as a result of G6 owner complaints combined with what issues I'm sure they were aware might be an annoyance to some. I thought mine was damaged before install because of noise I could make it produce by turning the input shaft and it did on one or two occasions put up some shift resistance comparable to what some G6 owners have complained about on the G6 forum.

You may have better results with the revised 07 version that addressed the shifting problems that 06 G6 owners alleged GM would not readily acknowledge despite the complaints. It's been a while since I've visited the Saab forum to read their reviews about the transmission.

The dual mass flywheel per GM "dampens the vibrations on which ever output shaft is idle depending on which gear it is in", there was no mention of noise reduction which I believe it contributes to under some circumstances considering there is no similarity between the F-40 and the Caddilac V6 6 spd other than the number of gears, a dual mass flywheel and a very similar noise. GM also stated; ". Tension between the shift sleeve and the shift rail also prevents the sleeve from vibrating while in gear" in association with the revised detent system for 07 so maybe the 07 tranny is quieter. I don't hear much fuss from mine until rpm drops pretty low.

Maybe over filling it with fluid will help quiet it down a little. Not encouraging that, just a thought.

Then again, based on GMs explanation of the dual mass flywheel, maybe the transmission noise would actually be worse without it as it appears it may be from what I'm now hearing from those not using one.

[This message has been edited by Joseph Upson (edited 08-22-2008).]

For what its worth, mine has rattled from day one. But only with the transmission in neutral and the clutch out. Fix, when in neutral I hold the clutch in. And Archie, see you at Fierorama.

Jack

quote Originally posted by J Gunsett: For what its worth, mine has rattled from day one. But only with the transmission in neutral and the clutch out. ...

DITTO. But most of the time my engine is louder

Is there a way to check for the rattle before the trans is installed ?

quote Originally posted by J Gunsett: For what its worth, mine has rattled from day one. But only with the transmission in neutral and the clutch out. Fix, when in neutral I hold the clutch in. And Jack

I haven't been able to drive mine yet, for unrelated reasons, but it only rattles in neutral with the clutch out.

quote Originally posted by CBulen: Is there a way to check for the rattle before the trans is installed ?

I don't think there is any need to, it appears to be inherit of the transmission at least for 06 so you can almost be certain that it'll be there. You can turn the input shaft and probably hear the same clunk that I heard in mine giving the impression a gear tooth was missing.

quote Originally posted by Archie: They don't all rattle but, Come to our Open House & I'll show you which shifter for ring is rattling on my cutaway G6 transmission. Archie

Now Archie just where did you get that cutaway G6 transmission?? Don't answer as it cost me enough money already.

As a side note, thanks to you and your crew PLUS Chuck, my car has been running great since you last drove it.

How about a pic of the cutaway??

After further reading on the subject, in addition to literature by GM, it appears that the noise is probably magnified as a trade off for a lighter flywheel. As I mentioned earlier the only time I notice any noise from the drive train is at very low RPM (during idle) and that's more a function of my camshaft duration causing a lopey idle that in turn causes the dual mass flywheel to oscillate (I demonstrated this in a video clip). Once the idle was smoothed out the noise disappeared. The dual mass flywheel probably weighs twice as much as what you all are using, ~38 lbs complete with clutch. The happy medium from what I have read is to have OE flywheels lightened which I didn't think about until a month ago, provided they are already on the heavy side.

Here is a brief read on the ZR1 dual mass flywheel that pretty much drives the point home:

http://www.zr1specialist.co.../flywheel-clutch.htm

The more I hear about the F40 rattle, it moves into the "learn to live with it" realm. Still Alex's transmission, even with his lopey idle, was much quieter, so I'm not sure engine vibration alone is the determining factor.

quote Originally posted by Joseph Upson: With everything bolted up, you should have "X" amount of depth for the throwout bearing to be pushed away from the diaphragm release flanges eventhough it will be touching them. In other words with the assembly together you should have enough travel room left inside the hydraulic bearing to fit a feeler gauge of the prescribed clearance thickness between the bearing and the diaphragm contact surfaces. I used an original G6 clutch disk and took it to the local clutch builder and had it rebuilt with Kevlar the same day. Not sure what the problem is with the builders on your end but my builder gave me options aside from the stock disc including a solid hub and also located a hub in his catalog that could have been ordered overnight for a completely new disc build like the OE unit. You should avoid spacers if at all possible.

About free play:
The info I was missing was that the F40 TO bearing is in contact with the diaphram fingers full time, even when the clutch pedal is released (clutch disk fullly engages/clamped). I did not know that this was different than regular TO bearings that are fork actuated. Thanks for straightening me out on this.

BTW, I found that the built in TO bearing spring requires roughly 15 lbs of pressure to compress it. Probably not important, but you never know.

Custom clutches
I don't know why no one in Reno can do this. I think its because Reno is too small. If you never been to Reno, people are surprised at how small it is (why I like it). Usually its just big enough to not be a problem getting stuff. But in the case of import cars, its too small. Example: there is only 1 wrecked 2nd gen MR2 in all of the yards in town.

I bought a brand new clutch from Rockauto, and its meant for a 20valve inline 5 audi motor, so it won't hold the V8 torque. So sent my Audi clutch to Clutchnet. They are going to increase clamping pressure on the PP and they are going to rebuild the disk with puck style friction material, along with changing the hub spline to match the F40. The Audi is factory rated for 300 ft lbs of torque (and 300 hp), and in the future, I will be increasing that to 400 ft lbs and around 400 hp. I am not running a power steering pump, so that frees up some HP.

Flywheel Spacer
THe reason for the spacer is because this very unusual engine (its a 20" long V8, from crank pulley to bellhousing face!) has a crank that only protrudes 5.6mm from the bellhousing face. The flywheel/ A/T flexplate register boss protrudes only another 10.2 beyond that. If the Fidanza flywheel (034 motorsports flywhee) is installed without any spacers at all, the ring gear butts right up the the back of the block. The A/T flexplate that comes with this engine (none of these Audi A8 engines came with MT in the USA) comes with 2 spacer plates from the factory. Actually, only one is used as a spacer, as the flexplate is sandwhiched between the two. I measured thier thickness in various areas, and their faces are at most .001 inch variation (out of parallel). Total runout with the flywheel installed and one spacer installed is about .002 inches. My guess is that you are advising avoiding spacers due to runout problems. The Audi guys that run this V8 all said without exception, that they used 1 of the AT spacers for thier flywheel.

I hear that Archie uses a flywheel spacer for his Chevy SB to F40 kit, and its at least 1 inch thick, but maybe I am wrong on this.

Anyway, I just measured the F40 bellhousing depth, TO bearing depth (compressed and extended), depth of the input shaft and splines, etc. All were measured from the bellhousing face.

I did the same with my Audi V8, and flywheel. Combining these measurements with the clutch and PP measurements, and calculating the relative locations of all the moving parts, I found I need an adaptor plate that is about 7mm thick, give or take. I just banged out some numbers on the calculator, so I might have plugged in a wrong number somewhere, so I will double check again, when I am not tired/sick. I am going to do an accurate side view CAD drawing of everything to make sure everything will go together, and that everything is accounted for, including clutch disk wear. It sounds anal, but its my engineering background. I would like to make sure of everything before I start grinding and drilling holes in my Audi V8 and my F40.

Since this adaptor ended up being so thin, steel is the best option for me. Aluminum won't cut it. Fortunately, the plate width won't be very much (maybe 3inches in some spots, and 1 inch in others), so it really won't weigh very much.

I ordered G6 axles (full set), and it will be interesting to see what it will take to make them work with MR2 parts. The G6 axles have come down in price since you last looked at them, still not cheap by any means, but not as bad as the last time I looked months ago.

EDIT: I did a more accurate sketch and dimensioned everything and back calculated the adaptor thickness. My calculations above only accounted for the TO bearing and did not account for adequate spline engagement of the clutch disk hub. It turns out that I need an adaptor of -0.5mm thickness (yes, negative). If the engine and trans bolted up, I probably would not need any adaptor, so what it simply boils down to is that whatever thickness I make my adaptor, I need to increase the flywheel spacer by the same amount.

The only other option is to have a whole new thicker flywheel made. I have the weird ring gear for the flexplate my motor came with, and I can buy ring gears about the same size from RockAuto (only $40 for those), so its just a matter of machining the aluminum flywheel.

[This message has been edited by CBulen (edited 08-25-2008).]

The Corvette people have had much experience with the trans rattle problem, myself included. The dual mass dampens the firing pulses that cause the problem.. The flywheels themselves have had their own problems. LUK, who made them, has had several redesigns.
GM wanted economy and some of the cars had the CAGS (computer aided gear selection) or skip shift feature. This forced you to get unwillingly into a tall gear at low rpm. The bad side effect was the lugging the engine which caused ratting of the gears. Idling had the same effect.
Many owners replaced the dual mass with a solid flywheel, usually a lighter one for more performance. the results being uncovering the noise inherent in the trans. The dual mass used a solid sprung hub clutch disk. Replacing with the flywheel with a solid one mandated using a sprung hub disk to give some degree of noise reduction and damping. Those who went from the original 34 lb. dual mass to an aluminum 15 lb or so ended up with diesel noises that made them wish you hadn't done it. Putting in heavier lubricant cushioned the gears and helped a lot. Some people burned the prom chips and raised their idle rpms. This was the best cure.
There never was anything wrong with the transmissions. Just a lot of heavy gears, all in constant mesh.
Hope this offers some insight.

quote Originally posted by MikeW: Putting in heavier lubricant cushioned the gears and helped a lot. Some people burned the prom chips and raised their idle rpms. This was the best cure. There never was anything wrong with the transmissions. Just a lot of heavy gears, all in constant mesh. Hope this offers some insight.

I was playing with the idle yesterday and at 575 rpm it sounds like marbles in the case...at 800 rpm it's less noticeable...over 1000 rpm, much less noticeable, (of course the engine is getting louder too, so that helps).

I was also wondering if overfilling would help. I found a TSB about overfilling the getrags. I suppose that is a common remedy for gear noise.

Hmmm... I havn't got my F40 project together yet, nor have I been following this forum for a while...
This is the first I've heard of a gear rattle and it kinda made me nervous at first until I realised the countless formula cars I've been around at idle and thier million dollar sequential tranny sounds like someone shaking a coffee can full of nails. I believe this problem with the F40 is a non-issue. If you want a performance built car on the street you should be willing to deal with miscomfort. If not, Buick makes a car for you. So what, your Fiero rattles and shakes like a racecar, bonus in my book.

quote Originally posted by MJ: I believe this problem with the F40 is a non-issue. If you want a performance built car on the street you should be willing to deal with miscomfort. If not, Buick makes a car for you. So what, your Fiero rattles and shakes like a racecar, bonus in my book.

That's good news...I thought mine was broken... so when you see my car at a show and it sounds like a bucket of nails rattling...no disparaging words, okay?

quote Originally posted by jscott1: I was playing with the idle yesterday and at 575 rpm it sounds like marbles in the case...at 800 rpm it's less noticeable...over 1000 rpm, much less noticeable, (of course the engine is getting louder too, so that helps). I was also wondering if overfilling would help. I found a TSB about overfilling the getrags. I suppose that is a common remedy for gear noise.

I don't think overfilling would help, there's already quite a bath going on inside. In fact it could cause a shifting issue. The synchronizer rings have to squish the fluid out to make contact on the gear cones and create some friction. If they're totally submerged it would make it more difficult. Getrag may have tested other fluids beside what GM recommends. That was the case with my ZF6 trans. So instead of the 5-30 GM fluid, I ran Castrol 10-60 RS (BMW engine oil essentially...$$$). Anyway, I'm using Redline MT-90 in the ZF6.
It is rated GL4 and has nothing to attack brass synchros. It's not as thick as is sounds. Just be aware that if you have any grinding
during shifting, its a bit harder to detect by feel with a cable operated trans. Not the same as having the shifter on the trans.

I assume none of you have heard 5speed's input shafts clacking away under the same conditions?

About 6 speed noise at idle

I just found this:
http://www.thesaabsite.com/...n+Vibrational+Issues

There are know issues on cars with manual transmissions where the bushing within the differential that inner driver slides into fails which causes vibration issues at idle/acceleration. Replacement of this bushing requires taking the manual transmission apart although some guys are sawing them out through the differential hole. We are working on a tool that will safely remove this bushing without harming the drive train and we should have this available shortly.

quote Originally posted by CBulen: About 6 speed noise at idle I just found this: http://www.thesaabsite.com/...n+Vibrational+Issues There are know issues on cars with manual transmissions where the bushing within the differential that inner driver slides into fails which causes vibration issues at idle/acceleration. Replacement of this bushing requires taking the manual transmission apart although some guys are sawing them out through the differential hole. We are working on a tool that will safely remove this bushing without harming the drive train and we should have this available shortly.

Just above that is another reference to noise and an association with the 900 series which does not use the F40. The noise is also attributed to transmissions which have apparently seen a good bit of use. The noise complaint with the F40 is present on install in brand new condition so doubt there is any association with the noise mentioned in the link.

quote Originally posted by darkhorizon: I assume none of you have heard 5speed's input shafts clacking away under the same conditions?

I've been driving since before you were born...I pretty much know what a transmission should sound like. The F40 when mated to a regular flywheel will rattle more than what would be acceptable in a new car. Some are louder than others depending on several factors, but the rattle is definitely there.

quote Originally posted by jscott1: I've been driving since before you were born...I pretty much know what a transmission should sound like. The F40 when mated to a regular flywheel will rattle more than what would be acceptable in a new car. Some are louder than others depending on several factors, but the rattle is definitely there.

I just stumbled across a statement notated in my 6 spd thread from the individual that built my clutch disc, indicating that if you are running a

SOLID HUB

you will likely have even more noise, regarding my curiousity about the small springs in the OE disc despite the exceptionally dampened dual mass flywheel.

quote Originally posted by Shadow_Wolf: Actually I believe the main purpose of the dual mass flywheel is to reduce engine vibration being transmissed to the transmission. GM and Ford started doing this with their diesels some time ago because customers complained of noise and 'gear rattle', specifically at idle with the transmission in neutral. Most aftermarket clutch manufacturers offer a kit to switch these to the much lower cost and FAR MORE RELIABLE standard flywheel. The GM and Ford DMF's were never a great design and tended to be problematic. Heavy trucks stuck with standard flywheels and for the most part, told customers to live with the chatter at idle. Much of this was reduced when they went to fine mesh gearing in the main box. I honestly don't see the advantage to having a dual-mass flywheel on a naturally balanced motor like the 60 degree V6. In fact I don't see it as an advantage with a properly balanced V8 either. As well all know diesels tend to shake like a bastard though even that has been reduced in the newer engines. My $0.02

Yeah, that annoying noise does suck. That's my one of 2 complaints. The second being the added flywheel weight combination that seems to be holding my motor back from being the fast revving motor I designed it to be... It does help it maintain 2000rpm @ 70mph in 6th gear though... But damn that noise sucks... I suppose smoothening out my engine would help...

quote Originally posted by Joseph Upson: I just stumbled across a statement notated in my 6 spd thread from the individual that built my clutch disc, indicating that if you are running a SOLID HUB you will likely have even more noise, ....

That is definitely not my case. My trany has had the same rattle with the pervious non solid and the current solid hub. No change at all.
Also I didn't notice any change from the 5 speed to the bigger mass 6 speed flywheel. If your engine is holding then I guess you don't have enough low end torque.

I didn't hear any rattling while I was inside MotorTV Fiero LT1 turbo/6-speed. Maybe he's running some type of twin/disk or something, but either way I think you guys should follow his lead.

quote Originally posted by madcurl: I didn't hear any rattling while I was inside MotorTV Fiero LT1 turbo/6-speed.

The difference in sound at idle probably has more to do with the idling characteristics of the motor, (cam, bore x stroke, # cyl, etc) and is not something you have much control over once your choice of engine has been made. Alex's car had very little rattle, (compared to mine) so the SBC is probably going to be one of the quieter engines, (in terms of transmission rattle).

yes, I agree...the rattle is an extension of the overall (un)smoothness of your setup. when it left Archie's as a stock 2.8 with a stock heavy flywheel there was no rattle
an aluminum flywheel and an un-tuned 3400 block'd engine later and the rattle is quite pronounced...