Vibration in engine- help!

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matthon

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OK, big block 4 speed, runs great, recently put in new gauges including oil pressure. Drove it to Vermont Thursday night, about a 40 minute drive one way.
I was about 5 minutes from home and it started to run like crap. It felt like it was not firing a cylinder or two, it was sputtering a little and vibrating- which were both regular about every 30 seconds.
I got to the light before my house and when I pulled away the clutch seemed to engage later than usual, at the end of the pedal travel.
I had a similar experience and it was the cap and rotor, so I ordered a new one. Yesterday I got out the sand paper and cleaned both.
No more sputtering, but it is still vibrating every 30 seconds, enough to vibrate the car as well.

I inspected the clutch, and nothing looks out of whack, I ran it without the water pump hooked up to see if that was it, no suck luck.

I do not hear any knocking or noise. I stuck a long screwdriver to my ear at various places.

I checked the motor and tranny mounts and they appear to be ok, but can't they break inside and cause vibration?

I drained the oil and checked for metal shavings, and it is clean and free of metal.

If I hold the clutch pedal down the vibration does not change.

This is the second time I've extended the life of the cap and rotor with sandpaper, so I am hoping a new one will get rid of this vibration, but I am not holding my breath.

What else can I check?
My fear is a spun bearing, but I am not sure of the symptoms of that, if I can even get the pan off with the motor in, and how to visibly tell that is the case.

Pics of the mounts below. The driver one looks offset, but it looks like it was made that way, the passenger one looks good as well, just a little slanted. I can't get a good pic of the tranny mount, but it looks fine as well.
 
Since it seems to be doing it all the time, check that your harmonic balancer hasn't turned on the rubber. Use a timing light and see if the marks are where they are supposed to be.
 
I'm goin for somethin in the bellhousin comin apart. you've got a vibritaion. That would explain that. Your clutch pedal is acting differently. That would explain that. I think the sputterin and missin was a totally separate issue. Don't worry about a spun bearing. You said the oil was clean. No worries there. I bet somethin in the clutch disk pr pressure plate is fixin to sling apart and tear some stuff up.
 
Didn´t you also have a hard time to do a burnout on dry base, clutch slipping?
 
I had no idea the harmonic balancer had rubber on it, or in it, or where ever. I tried to get the pulley off to spray can paint it a few months ago and it would not budge- but the balancer can turn lose?
Is there rubber between it and the crank?

I agree that the sputterin and missin was a totally separate issue. We will see what a new cap and rotor do for me on Tuesday.

I was thinking something might fly apart in the clutch too, but so far it looks fine. Its a Borg and Beck, with the three 'fingers' that the bearing/fork sit on, and it all looks good. I've turned the fly wheel and checked it out as best I could.

The clutch isn't slipping, but now whatever is vibrating you can feel in the clutch.

Its constant at about a 30 second interval.

There is a big Mopar show this weekend and I'm hating this right now, plus I drive this car as much as I can- and I don't feel comfortable driving it now.

What the #$%#@*&()!@$#%$%^$^^!!!

How can I post a video?
 
If the vibration damper has rotated on the crank hub, that could explain the vibration as well as the loss in power. If you're sure of the clutch, the damper would be what I would be focusing on.
 
Bad throw out bearing,was the flywheel balanced? I know,all the above and 2 more.Hope ya find the source.
 
All the input helps, I can eliminate things if I know what to check. This is a huge help so keep it coming.

I'll check the damper, but it sounds like if that is the issue it would need to be replaced.
Is there a way to check it without a light?

I'll check the bellhousing bolts. When you say pivot bracket, do you mean the Z bar pivot bracket on the bellhousing, or where the clutch fork attaches to the inside of the bellhousing?

Would a bad throw out bearing be visibly bad, or do you need to take it out and inspect it?

The flywheel balanced? Not sure. The tranny was rebuilt years ago by the second/third owner (father/son) and I believe they replaced the clutch at that time.

Probably not much chance of figuring it out and getting it fixed by the Saturday Mopar show.

Here are a few pics: its pretty greasy between the clutch and the tranny, slight leak from the input shaft, but I can stick my hand right up into the pressure plate because it is not a diaphragm clutch, and it is not wet. The oil pan is leaking, but not the rear seal.
 
I checked the local stores on-line and nobody has a balancer, NAPA does not even list one.
Jegs lists one but notes it has 6 holes evenly spaced- wrong!
Summit has one listed for the least at $208, but it will not ship until 9/9/2010.

I'll check mine tomorrow to make sure its bad.
I had no idea these would be this much, or this difficult to get.
 
Based on your original post, the car had been running well up to that point. So I doubt if the flywheel is out of balance. They just don't "go ut of balance". Either they are or they aren't and you would have had a vibration long before now. Harmonic balancer is another story. The rubber deteriorates between the outer ring and the hu, allowing the outer ring to slide and or wobble. You can try to check it be turning the fan belt and see if the outer part of the balancer turns while the inner part stays put. Easiest way to check is with a timing light. Pull and plug the vacuum line to the distributor. Connect the TL nd fire it up. Is th timing maek where it should be (whee it was last time you set the timing)? Is it jumping aroundd as the engine idles? You do have a timing light, right?

Try Rockauto they may have one, or Carquest if you have them in your area.
 
Yes the to bearing gets worn and can be off center.If you were rough on the balancer you may have damaged it.If you have grease between the engine and transmission you may have a seal leaking or bad input bearing.Grease and oil is not good for a clutch or related components.Personally,I have never had a clutch in a big block mopar that lasted 3 years. Hope ya get the car fixed soon.
 
Thank you again everyone.

No, I don't have a timing light, but I can either go buy one or have my friend around the corner check it. I would have checked it by now if I had one, or the time to go get one.

Looking at pettybludart's pic it looks like the outer ring is really off. Mine looks fine, like it has not separated anywhere, and it doesn't budge at all.

This is a new one for me, so forgive my stupidity- I need to check it out asap.

To date:
Got the cap/rotor today- no effect on the vibration.
Input seal on tranny is leaking, grease on fork and bearing, clutch does not slip.
Input bearing on tranny- clutch disengaged does not stop vibration.
Spun bearing- oil clean, really clean actually.
Bellhousing bolts tight.
Throw out bearing- not 100% sure but it appears to be ok.
The Z bar bearings and pivots were replaced last year, movement feels the same, vibration is felt when I take off, clutch seems to be engaging higher up on pedal.
Balancer? Hopefully checked out in the next few days.

For what its worth, the vibration is more pronounced forward of the front wheels, and barely present in the engine itself- my guess is its transferring most of the vibration to the car.
 
Just my head when I'm under there!
I didn't notice any issues with the exhaust, but I can easily check.
 
I checked the local stores on-line and nobody has a balancer, NAPA does not even list one.
Jegs lists one but notes it has 6 holes evenly spaced- wrong!
Summit has one listed for the least at $208, but it will not ship until 9/9/2010.

I'll check mine tomorrow to make sure its bad.
I had no idea these would be this much, or this difficult to get.
Check 440 Source and get one of their chrome cheapo ones...it works for me...89 bucks

2001083.jpg
 
Is it safe to drive this thing if it is the balancer?
I'm guessing it is not.
 
If it breaks loose and flys off,it could do damage to your car or others.It can also do damage to engine,as it is a balancer.For the price of the 440 source ones,I,d get one just for piece of mind.I feel this is your problem.
 
If I am following this correctly you said the clutch travel has changed. 2 areas that could be the problem: #1 The flywheels bolts were not torques to specs and they are loosening up.
#2 The clutch arm pivot in the bell housing has a problem - could be where it pivots or where the throw out bearing is held on the end.
 
Did you pull the plugs to look at them? Before you go replacing hard parts like the balancer I'd make sure it's just not a dead hole. Sounds like it is to me...
 
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