Highway speed, vibration

Question, I have a vs with a 1600 and 4.12 trans. Got it up to 70 (3200 rpm) on smooth Florida tarmac and there was a noticeable and constant vibration in the car. Not so much side to side as up and down. The rear view mirror was barley usable, and of I let my jaw go slack my teeth would chatter at about the same cadence as when your too cold.

Speed up and it speed up, under 60 it's barely noticeable. If I let the steering wheel go the car tacks reasonably straight but the wheel does vibrate from side to side. Not violently but pretty rhythmically.

Ideas? Flat spot in tires? Joints? Or has it just been 6 years since I owned on and with the 3:88 trans the engine sounded more like it was going to blow so I was only concerned about that?

Thanks in advance,

Amish

Build is brand new, tires are brand new, but pan is obviously old... Where is the little shock and is there a good way to check?

If the vibration moves the steering wheel back and forth it can only be a tire / wheel out of balance, a tire out of round, or a wheel coming lose and falling off. I'm betting $100 fake dollars it's a tire out of balance! What brand tire is it?

Steering dampener (I called it a compensator):
http://www2.cip1.com/SearchResults.asp?Search=steering+damper&sort=7&Search1=Search
Under the front of the car configured in the steering linkage. You'll need to know the type of donor pan you're running on...year/model.

If tires are old, could be a tread separation or just out of balance. Sometimes you can visually see a "bubble" around the circumference-that would be separation; any number of causes from age to running over a rock or pot hole...on and on. You can also check the date code on your tire.
A shimmy of the steering wheel could be a tired steering dampener/compensator (little shock absorber).

even new tires can be bad...a good balancer can figure it out while balancing. The cheaper the tire, the more chance of faulty tires.

I vote for wheel balance.

ditto

I agree with the above posts-alignment, or tires.
Are the front and back tires/wheels the same size? If so, you could switch them around and see if that makes a difference.

A good dynamic balance has become practically a necessity anymore because of how common tire imperfections have become. The bubble balancer isn't good enough even on some vehicles that never go very fast.

If you let the person doing the balance know that you intend to drive the car at speeds that might be over the legal limit he/she will give the job closer attention if you've got one of the good guys.

There are kits of beads or BB's that you can put into a tire that are supposed to provide a continuing balance regardless how the tire wears or how it's possibly abused. I've never tried those kind of products but I've been on forums where several people swore by them.

Someone with a better memory than mine might provide a link to the types of thing I'm talking about...

I tried the beads to cure an intermittent vibration at ~60 mph and found no improvement.

don't overlook worn/loose suspension bits and failing wheel bearings.

Check everything. Assume nothing.

angela

Ditto what Lane said regarding dyna beads. Not cheap and a total waste of money. The best balancing is high speed on the car balancing, but try to find a place that does that anymore. I heard somewhere that there were safety issues with this practice and OSHA got involved and put an end to it. You might find an independent out of the way place that still does it. I have a line on such a guy and plan to go see him before the next road trip.

Thanks for the ideas. Just to verify, for those of you that drive 70 and have a similar setup you don't have a noticeable vibration correct? Other than the high speed engine vibration of 3200 rpm.

Tires are nankang, I'll post sizes in a minute

i reiterate, the cheaper the tire the more chance of problems.
if the vibration doesnt go away after a proper balance id be looking for new tires,,did the car come with the nans? maybe kirk can exchange them. My last car from kirk came with Pirelli P4, a really nice tire.

Amish, does this vibration happen at 3200 rpm in 3rd gear? If not, it's the suspension/tires. Another way to check is drive along at 70 mph (with noticeable vibration) and put the gearabox into neutral. Is the vibration still present?
I suspect it's your cheap, Chinese tires.

3200 in 3rd no body vibration, at 70 in neutral still vibrating

So just take it to a Goodyear store and ask them to balance it first?

Wheel weights are known to come off from time to time. Start with wheel balancing.

You can get them balanced, but it may not solve your problem. A few years ago I had the wheels on my monster Miata (V8) balanced and put on my car. When I drove off I still noticed a vibration, so I drove back to the tire store. They put my car up on a hoist and spun the wheels. One of the front wheels had a noticeable wobble. Even though the wheel was bent they were able (they said) to balance the wheel.
So, a tire shop may be able to balance the wheel, but not fix the problem (like a defective tire).
One way to know for sure is to have it road force balanced on a Hunter wheel/tire machine. They can tell if you have a defective tire.
I have the wheels on my track Miata road force balanced, even though it's fairly expensive, because Miatas are notorious for vibrations at highway speeds.