Packard Forum Index » V-8 (1955-56)

I've got a project for all you V8 owners: Go look at your balancers on the front of your engines, whether they be parts engines or whatever, and tell me if they have any balance holes drilled into them. The reason why I'm asking this is that my key on the crankshaft of the Pat failed me again about two weeks ago, and I had to pull everything off. I noticed that the key way had taken quite a beating, (on the balancer, NOT the crank, thank God!) and decided to swap out the balancer from my 374 onto the 320. Here's where it gets interesting, the balancer that came off my 320 had two holes drilled in the side, right near the timing mark. The one that came off my 374, had no holes anywhere, and was painted cream, like the '55 Senior cars. What I'd like to know is, which one is correct? The parts manual only shows one choice, p/n 440715. Now, if there's two different versions, which I can verify, which one is correct for which engine? I'd really like to hear all your comments on this, as I don't know which one is correct for my 320, but I do notice that it runs a whole lot smoother now that it did before. (I plan on taking the balancer and flywheel in when I have the rotating assembly balanced, so everything's perfect) I'll try to get a pic of the one with the holes later tonight.

I believe I'm correct when I say that all the vibration dampers are the same across the V8 line; the holes you see are the results of the original balancing of the rotating assembly.

Parts Book shows only one P/N. Mine is original to the engine in the '55 Pat, has no holes and has original, "Packard Ivory," paint on it.

Aren't there two versions, one with the extra A/C pulley and one without? I'm not where I can look at a parts book.
I think those were balanced with the crank @ Utica, ergo the differences in the number of holes.

That's a sigh of relief, gentlemen. I was kinda worried that it was possible that there were differences between the engines. As for that A/C setup, I had the opportunity to view the factory A/C pulley setup while I was out in Vegas last year. The balancers are the same, but the pulley is cast iron and has two different size grooves in it, one for the power steering, and one for the A/C. Heavy SOB, too.

The drilled balance holes can vary form balancer to balancer. The AC pulley is CI for 55 and cast Al. for 56. My Exec has cast Al. AC pulley.
Eric, is the bad balancer a loose fit on the crank???? If so then that would cause the problem. It should be a light to medium press fit and require assembly by DRAWING it into place with a long bolt (3/4-20 ???). i believe the manual details the installation.

Note: Field service technicians will often 'polish' or hone out the bore of the balancers to make them easy and fast to install. This might be what happened to your pulley that sheared the key. Some mechanics will drive them on with a hammer which is not an all bad practice depending on how tight the fit is.
LOOSEN the timing chain cover bolts to allow the seal to centralize (also covered in manual).

Do u suppose the Super Charger fan is placing undue load on the balancer and key???? ESPECIALY if the balancer is just a slide on fit.

Well, this originally happened before I put the supercharger on, so I doubt that it's the cause. And besides, it's no more pull on the crank than the factory AC would be. I'm thinking I'm going the Jack Vines way and use a custom 302 Ford balancer on the 374. With everything that keeps coming up for this 374, I'll be lucky to get out with less than $10,000 in it!

ON second thot. MIC the snout of the crank, near the end and near the cover each location at 90 degrees to each other (4our measurements). I'll mic mine tomorrow. If i remeber rite it should fall on an even fraction (1.750 =/- .0005).
I'm suspicous that maybe some mechanic in the past has thrown a ribbon of emery cloth on the snout while running the engine just to make the balancer go on ez.

No, the "new" one went on rather difficult, and had to be tapped on, then I used the crank bolt to "pull 'er home".