Balance issue? Help!

[coronet70]

hi everyone. I have a 440 built in late '72. Having an issue with a shake that comes in at 2000rpms. I've confirmed that the drive shaft is good, u-joints good. I have a new 449 source weighted vibration damper, freshly rebuilt trans with weighted converter. Been trying everything.

The previous converter was not weighted, so I thought that would be my issue. The new converter has one weight, and it is almost in the same position as the damper weight. Is that right? The stuff only bolts on one way. Should I have the converter with weights distributed around the converter?

One more thing....when we had the crank shaft out, we noticed globs of weld on some of those counter weights. I don't have any photos, but I'm not sure that it should be there. Did someone try to internally balance a cast crank? I did try running with no external weights, and the shake is much worse. Getting frustrated. Thanks!

 

[Mike67]

So a couple of questions,
Does it vibrate out of gear as well as in gear?
Did it vibrate prior to the trans being rebuilt?
Was your motor balanced or at least the crank spin balanced?
Did you change flexplates?

 

[coronet70]

So a couple of questions,
Does it vibrate out of gear as well as in gear?
Did it vibrate prior to the trans being rebuilt?
Was your motor balanced or at least the crank spin balanced?
Did you change flexplates?

It did vibrate prior to trans rebuild, I had them get me a weighted converter.

It vibrates in park or neutral.

I believe the crank was "turned" but I don't think it was balanced. Not sure.

I didn't see anything wrong with the stock flex plate, so I reused it. Didn't look bent or cracked.

 

[PurpleBeeper]

Ohhh, that's an issue. How are your motor mounts? I'm trying to think positive that those are your only source of vibration. If you saw some welding on the counter weights, then somebody balanced it at some time. If you didn't do the balance job, then you have to find out exactly HOW it was balanced from the person who did it.

I do believe it's possible to neutral balance a cast-crank motor. If it is neutral balanced, the vibration would be caused by your weighted balancer & torque converter. For all you know, the old balancer was part of the balance (not neutral balanced).

My motor was balanced with the flywheel, pressure plate & balancer (big rod motor). When I had to change clutches, I checked the flywheel and it was not neutral balanced, so I had to "just try" a new pressure plate. My other option was to pull the motor and re-balance the whole thing. From now on, I will only neutral balance to avoid any problems, even though it might cost a lot more.

 

[coronet70]

Motor mounts look ok....maybe I can check them somehow. I'll have to look into it.

I realized that maybe someone balanced the crank in the past, so I tried an in weighted converter and took the removable weight out of the damper. So, I wound up putting the weight back in the damper and got a weighted converter.

The engine was rebuilt not long ago, but I don't believe anything was balanced....can't believe that nobody advised me to do that. Not the machine shop that turned the crank, or the shop that bore the cylinders. I did have a vibration before the engine was rebuilt.

I'm thinking the welds on the crank are throwing it off, but I'm no expert obviously.

 

[IQ52]

Most, if not all 1972 440 cranks were internally balance forged units. I'm with PurpleBeeper, find out who balanced it to what specifications.

 

[Mike67]

Was the old balancer neutral? I have a feeling the combination of the tc and dampner now being units used for externally balanced it may be way off!
Or like Beeper & IQ said, a motor mount &or find the specs...I have a feeling it's internal though and just a matter of some mismatched parts...hopefully!

 

[coronet70]

The old converter was neutral. Unfortunately I can't find out what was done to the crank. I've gone back 2 owners and they know nothing...ill check the mounts. If that's not the issue, I guess the motor comes out.

 

[RT K_line]

Is it a cast or forged crank? Some 72 440s have left over 6 pack rods and cranks too. I had a similar vibration on a 440 with 6 pack rods and pistons but it had a cast crank.

 

[coronet70]

I'm sorry Mike67, the balancer was weighted. It looked ratty, so I put a 440 source balancer on it with a removable weight. Shakes more without the weight. Got a weighted converter. Still shakes, maybe a little worse.

Should I just face the music and pull the motor and have the internal parts balanced??

 

[Mike67]

I'm not a professional mechanic by any stretch of the imagination...There are other guys here that are much more knowledgeable and would probably better than I to advise you where you should start...
Are you sure all of your plugs are firing? Is it detonating? Whats your compression, cam specs?

 

[coronet70]

I'm not a professional mechanic by any stretch of the imagination...There are other guys here that are much more knowledgeable and would probably better than I to advise you where you should start...
Are you sure all of your plugs are firing? Is it detonating? Whats your compression, cam specs?

I'm positive the plugs are firing. Checked that yesterday. Not sure about the cam specs.......I know it's the comp cams equivalent to a Mopar purple cam. As far as compression, do you mean the actual compression in each cylinder?

 

[Mike67]

I'm positive the plugs are firing. Checked that yesterday. Not sure about the cam specs.......I know it's the comp cams equivalent to a Mopar purple cam. As far as compression, do you mean the actual compression in each cylinder?

Your static... If the motor was already built you may not know it...just curious if you are have detonation issues....you might post a video of it running just so people could here what's going on...

 

[khryslerkid]

I'm thinking, you really need to identify what crank you have. Especially having a '72 engine when some changes were made. Read up on this and determine which dampner you originally had. There's other signs that you have that might come to light when studying this article. You have the info there to determine which crank you have. Once you know what crank you have then you can use the right dampner and TQ. You don't want to be guessing.

http://www.440source.com/dampers.htm

Any pics of the crank when you had the pan off. Do you have a good memory?

 

[coronet70]

Here we go...found this pic. Looks like cast to me.

 

[khryslerkid]

Good deal. Now you know you need a weighted dampner and weighted tourque converter. That's what's currently on there now, right?
If so, when checking the firing of the cylinders, did you pull plug wires, one at a time, while running, to see if any made a difference?

 

[coronet70]

Good deal. Now you know you need a weighted dampner and weighted tourque converter. That's what's currently on there now, right?
If so, when checking the firing of the cylinders, did you pull plug wires, one at a time, while running, to see if any made a difference?

I currently have a weighted balancer(I did speak to 440 source before purchasing), and a weighted converter. I pulled each plug and made sure that had spark, and triple checked firing order. Engine runs good, but somethings still causing it to shake. I don't feel that the mounts are bad.

 

[coloradodave]

So the engine idles and is smooth up to about 2,000 rpm and then starts shaking? Does it continue to shake going up through the rpm range? I would do the following:
1) Pull the distributor cap and check for carbon tracking on the inner terminals.
2) Check the distributor shaft for side play by pushing and pulling it side to side. There should be no perceivable play.
3) Check the reluctor wheel to pick-up clearance with a brass .008" gauge at several points.
4) Check each plug wire for resistance. Look for about 5K ohms per foot of wire. Were the plugs new with the rebuild?
5) As has been said, at 2,000 rpm (when the engine is shaking), pull one wire at a time and ground it. With a tach, read how many rpm each cylinder causes the engine to lose. Is one cylinder different?
6) With a timing light hooked-up, watch the timing mark move as the rpm goes from idle to over 2,000 rpm and beyond. Does it move smoothly?
Hopefully, the above tests will either find the source or eliminate the ignition system as the problem. This problem could also be the result of a partially blocked primary jet or stuck metering rod. Check ignition first.

 

[oldbee]

Have someone else looking under hood at engine then power brake it in drive and reverse; if a mount is broke you'll see engine jump up.

 

[oldbee]

Have someone else looking under hood at engine then power brake it in drive and reverse; if a mount is broke you'll see engine jump up.

If