Vibration on acceleration

[Henry's Lady's Man]

I think this is a recent development. I have an annoying vibration when accelerating, but not when I level off and coast. I believe it's present in all three gears. I hate to prejudice any suggested advice, but I'm afraid it has something to do with the crankshaft and good ol' babbit. It vibrates the dash and I can't remember it happening before.

I've had her for about 17 months and haven't driven her a whole lot, but had it out for a 150 mile round trip late this summer; I'm getting ready for a 400 mile trip.

It seems to be banging on all four, but now that I think about it, mostly I drive her a few miles, and may need to clean the plugs. But why does it vibrate mostly on acceleration?

[colin1928]

Over the years when I hear what you describe my 1st thought is centre main bearing
as always lots of other possibilities

[Dollar Bill]

"I have an annoying vibration when accelerating, but not when I level off and coast."

I've known faulty universal joints to act this way.

[Tom Wesenberg]

The first two answers are the first two things I'd check. If you rev the car in neutral, does it bang?

If it's the center main you might pick it up in neutral while revving the engine. Also if it's the center main, it will make noise with the engine speed as you shift through the gears.

If it's the U-joint the noise will be constant according to car speed.

[Mitch//pa]

if you have to clean the plugs every few miles are you running very rich??

maybe it wouldnt hurt to check the crankshaft endplay an easy quick check..

[Henry's Lady's Man]

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Originally Posted by Mitch//pa

if you have to clean the plugs every few miles are you running very rich??

maybe it wouldnt hurt to check the crankshaft endplay an easy quick check..

These are all possibilities that I will look into this weekend.
So Mitch, How do you check crankshaft endplay? It's quick and easy, you say. I'm a "late-bloomer", so how easy is it?
Two comments:
1). I recently lowered my oil level to the middle of the dipstick range (half a quart low) to stop a leak into my flywheel housing. It worked. Does that have ANYTHING to do with crankshaft endplay by the rear main?
2). I had a minor knock, down by the center main, as far as a stethescope could tell me. It could have been a valve tappet as well. I have not gone into the engine at all, for anything yet.

[Henry's Lady's Man]

Originally Posted by colin1928

Over the years when I hear what you describe my 1st thought is centre main bearing
as always lots of other possibilities

Colin,
I will probably have to take off the center main cap. I'm truly afraid of what the old babbit will look like. If I do, I'll post pix. I've seen some crumbly babbit pix on the barn, and I'm expecting something like that. I don't want to incapacitate my car, but sometime reality bites.

[Henry's Lady's Man]

Originally Posted by Dollar Bill

"I have an annoying vibration when accelerating, but not when I level off and coast."

I've known faulty universal joints to act this way.

Dollar Bill and Tom W,
OK, I'm just gonna admit it... though I've only driven the car some 300 or 400 miles in the year and a half I've owned her, and I've lubricated just about everything, I put off lubing the U-JOINT. I know, I know. I can hear it coming. - Chuck

[Tom Wesenberg]

To check the end play just use the hand crank and push in hard to push the crankshaft as far rearward as it will go, then use a dial indicator with magnetic base and set it against the crank pulley. Now you step on the clutch to push the crankshaft forward, and read the dial indicator to see how many thousandths the needle moved.

[Henry's Lady's Man]

Originally Posted by Tom Wesenberg

To check the end play just use the hand crank and push in hard to push the crankshaft as far rearward as it will go, then use a dial indicator with magnetic base and set it against the crank pulley. Now you step on the clutch to push the crankshaft forward, and rear the dial indicator to see how many thousandths the needle moved.

Thank you, Tom.

I can ask my club if they have that indicator, or ebay has them. Sounds easy enough.

[Mitch//pa]

crankshaft enplay spec is .003-.008

[Henry's Lady's Man]

Originally Posted by Mitch//pa

crankshaft enplay spec is .003-.008

Thanks Mitch. Just bought dial indicator from ebay. We'll see how it goes. Chuck