Hi all I have 76 2.0 efi car that runs and drives excellent the only thing is on the highway about 70 mph I get quite a bit of vibration thru the steering wheel nothing above 70 mph nothing below.... any thoughts? Thanks

try switching front wheels to the rear and see if it makes a difference.

Tires. Jack the front up and spin each one looking for wobble. Feel for broken belt. Check for missing weights.

Also may want to check the inside of the front wheels to look for dents in the rim. Dents in the rim will cause a vibration at one speed.

Spin the wheel and look at the inside of the rim for any kind of movement.

I found that my 911 had been seriously lowered and the bump steer manifested the way you describe. Once I bought an Elephant bump steer kit it stopped. However, I have not seen the same issue with the 914, and I have it lowered a bit, so this is just a thought.

How old are your tires? Do you think the tires are flat spotted from sitting so long.

while the front is in the air doing all of those other things, check the front wheel bearings.
With the wheel still on you should be able to push on the top & bottom of the tire and get noticeable "wiggle".
Now with the wheel off, try the same experiment with just the front rotor top & bottom.
You should not be able to get any perceptible wiggle with so little torque.
If there IS any wiggle, you can try to tighten the nut a hair to reduce the slop, but put new bearings on your list of near future upgrades.
AND if you have to replace bearings, check the rotors for thickness.
It is easiest to do that all at the same time.

I would check tires/rims for mud/asphalt.

I have the same problem. I have been hoping that a wheel is not damaged from a spring pot hole. Good ideas that are giving me something else to look for..

I just had new tires put on my car and have a similar issue. Turns out the wheels were not 100% true. They put the straightest of the 4 on the front and it is 75% better.

Stugray...are you saying there should be some play in the wheels bearings when moving the wheels and tire like you said?
Mike

I have found that the perfect torque is when you can barely get some wiggle with the wheel in place (and jacked up), but none when it is removed (applying force to just the rotor).

The other trick is to tighten the nut until you cannot move the washer underneath with the tip of a screwdriver, then back off a bit until you can (move the washer with some effort).

Then drive it for a few miles and check it again.

I've had your described problem twice although with cars not a 914. In both cases it was loose wheel bearings that was the problem. When the front wheel bearings were properly adjust the vibration went away. Adjust the bearing using Stu's technique.

Elliott, are you saying the 914 is not a real car?

If you balance our wheels via the center hole as most places do, you may not have properly balanced tires.

The wheels are lug centric and should be balanced using a lug adapter at a decent tire shop.

Also, watch how you mount them, you can drive in one bolt and pinch the wheel off center using an impact gun.
I mount them all by hand while rolling the wheel around and paying close attention to centering each bolt.

Oh, check the date code on the rubber. Seems 4-5 years is the max time to use a tire, good tread or not.

Lots of blow outs on the 356 s
Because of tire age, not tire wear.

Google DOT date codes for tires to learn how to read them.