Re: Clutch Chaaaaattttteeeeerrrrr!!!!!!!

I hope someone chimes in with the answer, because I'm fighting the same thing with my truck and I have no idea what to do next to fix it...already pulled the flywheel to have it surfaced, installed new pressure plate & disc while I had it apart, still chatters badly...

 

Re: Clutch Chaaaaattttteeeeerrrrr!!!!!!!

something worn in drive line? bushings,u-joints,trans mount?

 

Re: Clutch Chaaaaattttteeeeerrrrr!!!!!!!

Well worn drive line parts could do it but ujoints are new,mounts are new,and it did not do it before the rbld,only after the rbld did the clutch chatter start up after i had the original flywheel resurfaced,installed the new hays street/strip clutch,along with a new pilot bushing.

I am still tending towards the rougher surface the flywheel had on it after it was resurfaced possibly causing the clutch plate to grab harder during engaugement making the clutch plate bounce & skip up & down on/off inbetween the flywheel & pressureplate as the clutch is being engauged.

Does that make any sence to you guys and have you ever heard of the rougher surface on the flywheel post resurfacing causing this issue?

I also heard a high perf heavy duty clutch fork could alsotamethis beast,have you had any experience/s with trying one of those?

Scott

 

My money is still on the flywheel, I no longer resurface mine I replace with new. Jb

 

I'm with Jerry.

Re-surfacing the FW will generally remove the surface cracks but but won't address much of the heat spots, and they go much deeper than the surface cracks.

Replace the flywheel. I don't know how good an idea it is to run a used clutch disk on a new FW. Rather like running used brake pads against new rotors I imagine. Of course, if you replaced the disk then the same logic would dictate also replacing the pressure plate.

Dan

 

Here's some real world testing:

I replaced the OE type clutch with a DF when I had the 396. At that time I had the flywheel resurfaced also. Could never get the car to chirp the tires when shifting gears. Had the motor rebuilt, and at that time I bought a new flywheel. Guess what, chirped every gear (motor specs or anything else did not change).

So something goes on when the flywheel is resurfaced, and sometimes its not good. Cost me 60.00 for the resurface, new flywheel was 120.00.

Having said that, I just had my flywheel resurfaced for this build :clonk:

I think it depends upon the quality of the machine work. My machinist said that they use a diamond cutter for this operation. It does leave a rougher finish that a new flywheel I noticed. It would be wise to put this through a good break-in before applying full power, that way you give some for those ridges and clutch to smooth out.

The DF clutch requires a 500 mile break-in, think I'm going to take that advise.

 

Could it also have gotten worse by the hole being made a little to big from the factory in the new pilot bushing (where the input shaft seats ) allowing it to slop around when the clutch is not fully engauged yet?

I'm not sure what you're trying to say exactly here, but if the pilot bushing is sloppy it can cause some chatter. More likely it's the friction characteristics of the Hayes disc. They are more "aggressive" than a stocker type disc and don't like to be slipped.

Back in the day I had a '74 Z28 with a Borg Warner 2.43 1st gear trans. I replaced the original clutch with a Hayes street/strip clutch and it was just like you said, chatter city. Reverse was especially bad, like when trying to parallel park. I later swapped the trans for a 2.88 1st gear unit and the chatter went away. Putting the 2.43 trans back in and the chatter returned.

My advice to you would be to put a good quality stocker type disc in it. You can still use the Hayes pressure plate. Something like from Napa or whatever parts house you have in your area that you like. Just use a quality piece, not some $19.95 special. If there is any question about the pilot bearing replace that too while it's apart. I'm guessing from your signature that this car is a cruiser and not a racer. I think you'll be much happier with the less aggressive disc.

This isn't to knock Hayes. They aren't my favorite but any of the "street/strip" type discs behave the same way. They all work much better, less likely to chatter I mean, with more gear, lighter vehicle, etc. Whatever it takes to not have to slip them to get going. Just my opinion, but I've been to that movie.

 

Leaving greasy finger prints on the disk and surfaces will cause chatter.

 

No,no greasy fingers here,i dont do sloppy work like that.

It makes a lot of sence what you guys are saying about the more aggressive material on the Hays disc reacting badly with the little bit rougher surface of the re-machines flywheel casuing it the chatter more inbetween the flywheels & P/P while engauging the clutch.

I guess if i should remove the trans and replace the clutch disc at the very least.

But i am still undecided about the replacing the flywheel too since the more agressive material on the hays disc could be the major part of the problem.

I guess i will make that decision when i remove the clutch dist & see if the resurfaced flywheel has smoothed out some since i have 3k on the clutch.

If its. smoother i will leave it but if the its still rough i guess i should replace it.

Thanks

scott

 

I did a goggle last night on this and got a lot of info.
one drop of oil from the rear seal was the main one
aggressive clutch and pressure plate
excessive run out on the flywheel
motor mounts
trans mounts
u joints
and too much backlash in the rear end gears
my jeep has the oil problem I'm sure because the dip stick broke and blew oil everywhere now it chatters like crazy.

 

Hi guys,i have a #'s matching bone stock 1969 chevelle ss 396 with the original flwheel,trans,etc and now have pretty bad clutch chatter.

Before i rblt the motor in 2001 it had a little to no clutch chatter but iafter the rbld is when the chatter showed its ugly head. Durring the rebuild i installed a new std bronze pilot bushing,had the flywheel resurfaced,and installed a new hays street strip 11" perf clutch that has a little more clamping force along with of course a new throughout bearing too.

If i am at a stop and engauge the clutch just right keeping the rpms real low like 500-550 while engauging the clutch it doesnt chatter but oilpressure drops real low while ding this due to the low rpms and i dont like that at all.

If i run the motor rpm up higher to approx 1600-1800 rpms when engauging the clutch then your slipping the clutch too much while engauging it but there is usually very little no chatter doing it this way either.

But when i engauge the clutch at like approx 900-1200 rpms where you should really be while engauging the clutch so you dont slip it too much and its not too low of an rpms where it's easier to stall and the oil pressure goes lower it shakes the car like heck even shaking the hood all over the palce too.

Could the chatter have possibly gotten worse after rebuild due to the slightly rougher surface post having it resurfaced causing the clutch plate to grab it harder and shake untill i get the clutch is full engauged? I have approx 3k miles on the new motor/clutch and the chatter is still the same,no worse or no better and i would think the flywheel surface would have smoothed out some by now reducung the chatter some after 3k miles if that was the case?

Could it also have gotten worse by the hole being made a little to big from the factory in the new pilot bushing (where the input shaft seats ) allowing it to slop around when the clutch is not fully engauged yet?

I have also read that a special heavier duty perf clutch release fork/arm made by maybe LAKEWOOD or someone can help or eliminate this issue,is this true?

Again,this car has never been played with like having parts from different cars & yrs all put together, its all the original parts with only a mild clutch upgrade to a little stiffer street/strip stock sized 11" hayes clutch pressure plate,thats it.

After the clutch is fully engauged the drivetraine is smooth with no vibes at all.

Whats do you guys think would fix this situation?

Scott

If you going to all the trouble of removing and checking things, check the clutch with a straight edge and see if it's flat and not cupped, same with the flywheel. Look for all the springs in place, disk and clutch.

 

Scott, and Vince ..... I know some machine shop somewhere is going to hate me saying this but ........ if you are getting a rough finish on your flywheels, the guy using the grinder needs to learn how to use it. We use a "diamond" wheel on ours and the finish is extremely smooth. The secret is to let the wheel "spark out" when you are done cutting. You can't rush it, we just walk away from the machine and let it run for a few munutes by itself. When you go back the flywheel is better than new.

We regularly do a couple a day and do not have any chatter problems.

 

Bill, its not "rough", but I can see a directional swirl around the flywheel. The new one was smoother, like a mirror, no evidence of machine work.

 

Vince,
The new flywheels are finished on a lathe, like a brake rotor. When you refinish them it is done on a grinder that does leave the "swirl" pattern like you say, but it should just barely be noticable if done properly. I absolutely should not cause clutch chatter in any way.

To be honest with you, after reading the original post again, I wonder if it is driving technique causing the "chatter". It may just be that the engine is getting loaded down to a bad spot and needs a few more revs to get it smooth.

Scott .... bad motor mounts will cause a similar situation too.

 

Bill,i really do know how to engauge a clutch correctly & thats not the problem but i do a some more questions for you since this is your buisness and you know whats going on. When i remove the flywheel other then checking it with a straight edge and looking for obvious coloring/heat issues how can i determine if the surface is in fact smooth enough and was resurfaced correctly prior to install or if it needs to be smoothed out/resurface a 2nd time to correct it? (Remeber,the Flywheel/new clutch has approx 3k miles on it so keep that in mind when you explain what the flywheel surface should look like at this time after 3k miles & not what it looks like right after it was re-surfaced and had not been used yet).

Again,i had absolutely no clutch chatter at all no mater what rpm i engauged the clutch at PROIOR TO THE MOTOR REBUILD WHICH INCLUDED A NEW HAYS STREET/STRIP CLUTCH KIT & THE ORIGINAL FLYWHEEL BEING RE-SURFACED & NEW STD BRONZE PILOT BUSHING,it was after the new clutch & flywheel re-surface was done that the clutch chatter started. I had a ZOOM street clutch in the car prior to rbld and there was no clutch chatter,i should have just reused that clutch but no i had to try to do things right and replace that ZOOM with approx 8k-10k on it with a new HAYS,(DUHHHH!!!!) The same trans & bell hoiusing,clutch fork etc were reused to no difference there either. Again the only changes made were the new street strip clutch & reusurface of the flywheel.

It seems like it almost has to be a problem/incompatibility of possibly a more agressive clutch disc material and the surface of the flywheel unless possibly the new clutch disc was defective being bent/or warped right out of the box when it was new.

I bought a new a std/stock rep clutch kit for this time around because my motor is a mild 396 with approx 365-370hp/430lbd trq and that same stock clutch is also used on 427/390hp,LS5 454's,olds 455 trq monsters in 1969-70 so i figure that stock clutch should handle my motor just fine since it also fits & can handle much stonger motor apps. There is no way i am going to chance reusing/re-installing the new (chattering) Hays clutch a second time just to possibly have it chatter again. I also figure since its a Sat/Sun car show/cruiser (which doesnt see any strip time) that i only wind up to approx 5,500 rpms through a few gears once in a while from a rolling start with no burn outs etc the stock clutch should hold just fine. Do you agree with that reasoning esp since same GM clutch is used for an LS5-454 & 455 olds in 1969-1970 with more power/trq?

The motor mounts are new stock repl types with approx 10k miles on them so i think they are ok. But you never know maybe one is broken. But before i pull the clutch out i will 1st start up the motor,pop the hood ,enguage the parking brake,and then try to move the car to see if the motor lifts up too much on the drivers side or if its lifts far enough hit the metal safety catches built into it which i would think shows its weak/streached/or borken,would that be correct?

Lastly,is there any reason to have the new stock new rep clutch ballenced or should it be fine,its an AC/Delco stock replacement clutch kit pt# 381258?

Sorry to ask so many qustions but i am trying to ensure i get this squared away when i install the stock rep clutch this time around,it's not fun pulling tran's/flywheel/clutches/etc,getting too old to be doing this suff lying on my
back with out a lift. I used to change a clutch in a chevelle in approx 3-4 hrs when i was 18,but at 51 it definately takes me longer for sure.(UMPH!!!!)

Thanks....Scott

 

I know this sounds dumb.

maybe too much thrust in crank/bearings?

 

Hi Dan,how is you hot 454 rinning with that nice Voodoo cam?

Also,didnt you recently put a new clutch in your car? If yes what brand & type(std replacement or street/strip),did you have the flywheel resurfaced,and is there any chatter at all?

By too much thrust do you mean the thrust portion on rear main bearing is too thin or do you mean there is too much front to rear movement of the crank assembly?

If the problem is too in fact too much thrust how does that cause chatter & how would i check for that with motor in car?

Scott

 

Hi Scott!

the 454 still ran great before winter....haven't started it yet this year.

I did buy a new CF clutch & steel flywheel but have not instaled it yet.
the current clutch is still good but I don't know for how much longer with the new found power.

I think you'll be able to check the front to rear movement with a prybar on the balancer. just be careful to pry on the inside of the balancer not the rubber mounted ring.

again, this may sound way off to the engine/trans gurus

 

It's all mounted to the crankshaft so end play is not a factor.
Clutch chatter is the uncontrolled oscillation between the clutch and the pressure plate I have seen brand new pressure plates found to be the culprit before all is said and done.
The higher the pressure on the pressure plate the more the springs will try and rebound so you need a higher rpm launch to go with that increased pressure plate.
If your not racing I would put in a stock pressure plate while your in there and try to get one with more fingers than 3 to help controll the plate better.

 

scott, i had the same problem with my 67 el camino. it drove me crazy. i tried nearly everything. another new clutch, different flywheel,fork, bushing,and everything else. i finnaly changed my m21 muncie to a m20 and the problem was gone. i tried to understand why for a long time. then i ran into a friend of mine that is an old time tranny expert. he's been rebuilding automatic and standard trannys for more than 40 years. he says the problem was a worn main shaft and he says its a common problem. i never took the m21 apart to see, but i bet he's right. he says it doesn't take too much wear to cause the problem.this man is a tranny genius and he rebuilds an average of five trannys a day for forty years and i trust his opinion. note that gary anderson says when he changed trannys the chatter went away and when he changed it back, the chatter came back. i personnally don" think the gear ratio difference is the reason. if you bought a new vehicle there would not be a chatter no matter what tranny it came with. just my 2 cents good luck

 

scott, i had the same problem with my 67 el camino. it drove me crazy. he's been rebuilding automatic and standard trannys for more than 40 years. he says the problem was a worn main shaft and he says its a common problem. good luck

I think what he was referring to was the splines were worn on the main shaft.
I really like the idea of the bolts I never thought of the tranny hanging on the disc and warping it but it sounds plausible to me.

 

Worn tranny mount?

 

It was pointed out one time that people crawling under the car will get the transmission most of the way in then let it hang on the clutch disc while they get ready to slide it the rest of the way in. This is said to warp the disc just enough to cause chatter. I had a bad case of chatter in our Lemans and suspected that it was my fault. We had the flywheel ground again, new pressure plate and disc and all was well. I made up 4 long studs so that the transmission slid straight into the bell housing and wouldn't be hanging on the disc. For what it's worth everything is as smooth as silk now.

 

Not trying to hijack the thread, but I have a question.

Is there any credence to the theory mentioned that a cut flywheel won't chirp the tires, only a new one will.

I have always though this was in relation to how the clutch was adjusted.

 

Vinsales,

In my situation it was indeed the gear ratio/clutch disc combo that caused the chatter. The Z28 I used in the example was @1 year old and around 10K miles at the time. The original 2.43 trans had no excessive wear and went back into the car with a stocker type disc when I traded it some years later. The used car appraiser remarked what a smooth shifting and great driving car it was. Over the time that I had the car I swapped the trans' a few times do to breakage (stupidity) etc., and always used a stocker type disc with the 2.43 trans and the more aggressive street/strip type disc with the 2.88 trans. BTW, that same 2.88 trans that I bought brand new in '75 for $440 including tax is still in my Chevelle today.

Scott,

51, eh? Kind of an old fart to be rolling around under a car aren't you? I am also 51 and like you I can't R&R a clutch as quick as I used to. But I attribute some of that to being a little smarter now and looking at things more closely while they are apart instead of racing to get it done only to have to redo it a couple of days later. Of course back then the cars were much newer and didn't need to be inspected for worn linkage, weak motor mounts, bagged out pilot bushings, etc. like something that's 35-40 years old. At least that's the story I use. Oh, and I use a trans jack now.

I think you'll like your new clutch. I used GM stuff back in the day and was always happy with it. I guess I wasn't aware they sold that stuff anymore. I'd be interested to know makes the GM stuff. Any chance of taking some pictures before you put it in?

Good luck,
Gary Anderson

 

GARY/KEN/GUY'S,thanks for all the great info & experiences you have all had with eliminating clutch chatter,it'sbeen very helpfull which i am sure will get me squared away.

Gary,i was told LUK still makes the std/stock repl clutch for GM but i dont know if the clutch kit i got was NOS oor if GM still stocks them these days.

scott