Can you say shimmy

[tbirdman]

I ran over a speed bump at a fairly low speed yesterday, however what I experience was quite alarming. My 32 starting to violently shimmy from side to side even when I slowed the car to a stop. After about 5 seconds it stopped. I had experienced a slight shimmy before going over the speed bump in the past, but nothing like this. Going over the next speed bump a few 100 feet down the road cause no shimmy. I was only two blocks from home so I haven't driven it further. Teh car drove fine before all of this.

I haven't looked under the chassis yet, but it sure seem like something was completely shot. Any ideas when I do my search?

[West Peterson]

Wow. I don't have a specific answer, but I'd check everything from king pins, tie rod ends, to steering linkages. Also check to make sure the wheel lug nuts are on tight.

[Guest imported_Speedster]

I've heard that some peoples Hands shake when they've been Drinking too Much.

[Guest JT]

Maybe it was a case of aeroelastic flutter, other than that I have no idea

[Earl B.]

Rick, maybe the Packard had too much alcohol in the antifreeze, and that's what made it shake... just can't hold it's alcohol.... like those shakey folks..certainly ono one here.....I'm sure!!!

[Owen_Dyneto]

My 34 Eight, essentially the same front end as yours, did this badly when I first bought it. It was most severe when crossing RR tracks at a diagonal. Checked all the front end components and found nothing loose. The cure was to have the front wheels, tires, and brake drums balanced as a unit by a truck shop which had the correct rig to fit the 17 inch wheel. Never a shimmy again. Only downside is you've got to mark the tire location on the rim, should you ever have to fix a flat, and also mark the position of the wheel on the drum, usually done with a daub on paint ont he wheel and drum.

[Matt Harwood]

I don't know how likely it is with the big tires and wheels on a Packard, but we had an untraceable shimmy on our 1930 Model A Ford. We rebuilt the entire front end, new bearings, new brake drums, anything that might cause a wiggle. No improvement. Then we bought new tires and rotated one of the front wheels to the spare and the problem vanished. Bent wheel.

Is that possible with a big car like this? They're pretty robust, but after a hard bump, I guess it could happen.

In addition to the other obvious stuff, double check all the leaf springs and their mounting hardware. They're the only thing holding your axle under the car.

Let us know what you find. I know it can be frustrating.

[mrpushbutton]

An essential comment that Owen Dyneto made is "checked all front end components"-- this is a very important thing to do, and is sometimes overlooked in some restorations <span style="font-style: italic">("Aw, that's a great old car, there's nothing wrong with that") </span>

I would make a serious assement of the front end just to be sure, then follow Owen's advice re: whole-assembly balance.

[Guest imported_Speedster]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Packard32</div><div class="ubbcode-body"> maybe the Packard had too much alcohol in the antifreeze,</div></div>

Yep, That's Definitely the Problem!

'Too much alcohol in the antifreeze'

I knew we could solve this problem, if we all worked on it!

[tbirdman]

I suspect something is wrong with the front end. Car rode fine until I started to notice a little shimmy on this speed bump late this summer. However last Saturday itturned into a much bigger shimmy.

The tires have been trued last year which helped with a vibration problem I had.

[West Peterson]

Maybe it's time to try a nice new set of black sidewall tires.

[K8096]

That's why 1934 Packard Twelves have those huge, heavy front bumper ends on them - to help control front end shimmy.

[Guest superods]

Birdman....I have three sets of front and rear suspensions for 32's sitting around here. You might consider scarfing one or so of them up. You know I would give you a great deal !!! I would even take that steering wheel as a partial on them.

[tbirdman]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: superods</div><div class="ubbcode-body">Birdman....I have three sets of front and rear suspensions for 32's sitting around here. You might consider scarfing one or so of them up. You know I would give you a great deal !!! I would even take that steering wheel as a partial on them. </div></div>

You mean I would take the suspensions off your hand as partial payment for the steering wheel:D

[tbirdman]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: K8096</div><div class="ubbcode-body">That's why 1934 Packard Twelves have those huge, heavy front bumper ends on them - to help control front end shimmy. </div></div>

I already have those on the 32. There were standard for 32 deluxe 8s but Ithink in 34 and maybe 33 they were optional for the Super 8s.

[tbirdman]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: West Peterson</div><div class="ubbcode-body">Maybe it's time to try a nice new set of black sidewall tires. </div></div>

Actually if I had to do it over, I may have opted for blackwalls, but I may have went with chrome wires with the BWs.

I actually will have blackwalls for my sidemounts. The whitewalls I have are too oversized to add a sidemount cover. So when I add the cover, I have a pair of blackwalls I bought used. So even though you won't see them, I'm 1/3 of the way to where Wes wants me to be.

You should had seen the color of my underwear when I started to get that severe vibration. All I could think of was the Tacoma Narrows bridge

[West Peterson]

Good visual... about the bridge I mean. The one about the color of your shorts I could have done without.

[Guest superods]

Ok boys ...while searching for Packard parts I ran across this article on the subject at hand. I sent it to the man himself but thought some of you would be interesting in what they had to say for future reference. I know I learned something when I read it.

[Tom M]

Rods,

Where is this article that we all read?

[tbirdman]

Here's the article. It's interesting because I found this article when I was looking for a solution for my front end vibration problem which was eventually solved by trueing the tires. However it seems like I may have this shimmy problem now describe by the article.

[Guest superods]

Sorry all. I forgot to copy and paste it !!!!! Thanks for doing so Birdman.

[Guest imported_Speedster]

Is it possible that there's also a design flaw with the '32 front-end? Not enough Caster or Camber, maybe? And the the design error shows up when there's any loosness, from ware?

Ken,

Have you checked the caster & camber, to see what angle they're at?

[tbirdman]

I haven't had chance to look at it. My 12 Cad is sick and I've been working in that. A little easier to remove the hood on a 12 CAD

[Owen_Dyneto]

At the risk of being repititous, I've been there with almost the same car and the same problem. Were these cars "shimmy free" under all conditions when new? Of course not, an occasional slight shimmy under extreme conditions can and will occur from time to time. Anything more than that requires a really comprehensive examination of the front end. Even if the Bijur is operative and has been used regulary over all the years the car is in service, there is still the chance of wear in the spring shackle bolts (new ones are available); if the Bijur was not in continuous use or hasn't been used regularly, you can be bet there is excessive wear. Also check and repair as needed any slop or play in the tie rod ends, king pins, drag link, wheel bearings, etc. Then have the front end alignment checked (you'll need a truck shop if the axle requires bending or if you need tapered shims for kingpin angle), and then balance the tires, wheels and brake drums a a unit.

There is a tendency for people to ignore the Bijur when its becomes inoperative, that's a direct route to these kinds of problems.

PS: It's kind of obvious, but have you checked to be sure the wheel lug bolts are all tight?

[mrpushbutton]

To quote an old mechanic I once worked with:

(sic)

<span style="font-style: italic">"The reezon for de greezin is to keep the shaft from freezin" </span>

[Guest superods]

Birdman...I see you are working on your caddy. Do you also do the same on that beautiful 903 of yours? Did you ever think maybe the problem may be right in front of your nose???? Ah Ah ...in this case right behind your nose !!! I am just funnin. We all need to laugh at times. So smile and enjoy life. Happy Thanksgiving ..one and all..

[idrjoe_sandiego]

What you have is a very common problem on I-beam front axles and it's known as caster shimmy. It usually occurs after hitting a hole or bump at relatively slow speeds and can be extremely disconcerting to both the driver and especially the passenger(s). It's probably best to slow to a stop, but if you are brave you can accelerate out of it, too. Obviously it's best to fix the problem and soon. Take your car to a qualified frame and axle shop, preferably one that deals with larger trucks (which still use the I-beam axle) and they will place some caster shims like the ones in the enclosed picture between your axle and the leaf springs. Think of caster like front bicycle wheel with its long fork jutting out ahead of you. This is what allows you to "Look Ma, no hands!" Ask the shop if they have any caster shims in stock and if you get that "deer in the headlights" look, leave that shop ASAP.

[tbirdman]

I believe I have found the source of the shimmy. The bolts holding the left front axle to the springs were very loose.

[Rusty_OToole]

In extreme cases you might consider a steering damper. Off road places sell them for 4 wheel drive trucks with solid front axles.

They are made by shock absorber companies (Monroe, etc) and can be got at any auto parts store once you convince them to look it up.

[Leif Holmberg]

tbirdman,When I restored my 1923 4cyl.Buick I used shackles from a 1927 Buick on the rear of front springs and I got the same problem as you deskribed.When I drove in a pot hole the car shimmy as much as I had to stay.I changed the shackles to the originals for 1923 3/4" shorter than 1927 and the problem was gone.

Leif in Sweden.