Engine vibration help!!

[EDS]

After supercharging my car, I needed a new clutch as I was overpowering and smoking the stock clutch in 3rd gear. I put in a king cobra and had the flywheel resurfaced (2nd time for the flywheel- 2nd clutch). I had a vibration that I did not have before the clutch job- slight after 2200 rpm, bad after 4300 rpm. It does it in all gears, or neutral if reving the motor. I was told that perhaps I got an imbalanced/defective pressure plate. I replaced the clutch with a second king cobra assembly. Vibration is better, but not gone. Could the resurfacing messed up the flywheel (second resurface)? My motor mounts are good, and this problem did not start until the clutch job.
A friend suggested the possibility that the ring slipped on the harmonic balancer, but I've been able to time the car and it's running great. Do I replace the flywheel, clutch, both? I need to fix this before I chew up main bearings or other parts. Please help, as I do not have $$ to just throw parts at the car.

 

[cjman15]

maybe the clutch and fly haven't properly seated??

 

[EDS]

I never heard of a clutch needing to seat. Antbody else have any ideas? I'm stuck here.

 

[Daggar]

Pardon me if this is a silly question but... during the clutch install... did you use an alignment tool or did you eyeball it?

 

[Slvr351Stang]

I went through somewhat of the same problem except I replaced the flywheel, and double checked that I torqued the bolts down right. That solved my problem...


-Jon

 

[TT91]

Pardon me if this is a silly question but... during the clutch install... did you use an alignment tool or did you eyeball it?

if your trying to get somewhere with that question, the input shaft of the tranny will ONLY fit on when the clutch is properly lined up with the shaft. Maybe the re-surfacer has your flyhweels mixed up....

 

[EDS]

The installer is knowlegable and knows his stuff. I was told that perhaps since the flywheel was resurfaced twice, and unk. was shaved off each time, perhaps it's getting thin and slightly warped during install.

 

[Js5ohLX]

I've got the same issue, but I almost think I have the wrong flywheel, is there a way to tell what balance a flywheel is? I had two, one off a 87 and one off a 91 (supposedly), I used the 87 one, and now I have the wicked vibration. The only thing that worries me is the flywheels looked different, and the clutches had different bolt patterns. Sorry to steal the thread.

 

[Badlilstang]

Did you use the three alignment pins?

 

[v8only]

guys, the clutch is almost impossible to bolt in wrong. As discussed, the trans won't go in without it being lined up. You wouldn't be able to bolt the pressure plate up without having it on the correct pins anyhow.

all flywheels from 81-93 have the 50 oz balance on them. It would be impossible to get the wrong flywheel, as you'd have to get one from an 80 or older with a 28 oz balance. then, that's a 10 inch clutch, and the pressure plate and clutch disc you have would be too big for it.

I've resurfaced my disc 3-4 times already with no problems, I don't think that's your issue either.

Are you positive the vibration's coming from your engine?? i'd almost lay money on your driveshaft causing the vibrations. You got it in in a wrong position, or you need an alum one. try rotating the driveshaft and bolting it in a quarter notch over and driving it. See if the nature of the vibrations change. keep trying that. unless you can really feel the vibs coming from the engine, it's probably that shaft.

what kind of condition are your motor and trans mounts in?? You could have torn a motor mount if it was real old and you let the trans hang from the engine.

 

[Badlilstang]

If he didnt use the three alignment pins to posistion the pressure plate center its very easy to get a vibe. Ive seen it more times then one. As far as flywheels go the only reason he would need a 28oz balance would be for a stroker as most are done with a 28oz balance or an older motor.. much older. The clutches them selves are zero balance and should not vibrate. I had a SPEC clutch I had to get rid of as it put a very noticeable vibe in my car. IF the car vibrates in neutral sitting still and reving it up.. its NOT your drive shaft as the car would have to move to get that vibe! Your drive shaft sits still when the car is sitting still free reving. Ive had tons of vibes through out the years that ive had to figure out on my own. Your vibe is NOT in your drive line. Did you put back the 3 alignment pins? If not thats where I would start... I just went through this 2 months ago with my buddies car.

 

[Badlilstang]

Surfacing the flywheel twice isnt going to make it thin enough to warp. When you have them surfaced they remove the three alignment pins to surface it and every time I have one done I have to ask for my pins back as they forget to return them. Some mechanics believe they are not needed but ford and most mustang mechanics will tell you different.

 

[Js5ohLX]

Mine vibrates with the clutch pedal pushed down sitting still, and as far as my two flywheels, one has a smaller clutch than the other. But the splines are the same, I'm just going to buy a new clutch and flywheel.

 

[EDS]

The vibration is rpm dependant, not speed/gear dependant. It happens in neutral. As far as the pins are concerned, I will check to see if they are there. The mounts are good- the engine does not move around under a load. I am going to replace the flywheel and clutch and see what happens.

 

[Js5ohLX]

EDS, we have the same problem. I'm changing mine tomarrow, let me know if it solves your problem, also if your running the clutch fan, make sure it's messed up.

 

[87fast]

hey i put a new centerforce clutch in my car and had to to use a 10 inch flywheel from an 86 gt . the flywheel didnt have the pins in it so i just lined the pressure plate by eyeballing it but i did have have an alignment tool for the clutch. i doubt its possible but just wondering if all the bolts on the pressure plate are tight and not over torqued .i could be wrong but heard its not more than 20 foot pounds needed.i would have got the correct clutch and all but it i got a killer deal cause its a dual friction that was a month old ,the throw out bearing and flywheel for a 125 bucks.