Originally Posted by elp_jc
Is it also intermittent, and between 60 and 65 mph? Wonder if it's wheel/tire or suspension/steering related. Mine is not bad enough to do anything about it now, but will be watching it. Thanks for your comment.
You should have your front wheels spin balanced to see if one of your wheels are bent.
If that is ruled out as the root cause, then it's very likely that you have a brake rotor problem. (embedded brake pad deposits)
The reason it only shows up at certain speeds, is due the centrifugal force involved in spinning a large round object like a wheel, brake disc, or tire.
There is a point where the revolutions per minute (rpms) are just right to re-create the shaking (vibration) which results in a out of balance condition.
You'd think the shaking would be consistent with predictable linear progression...but it's not. It's very sporadic due to the harmonic balancing issues mentioned above.
It only takes a small shift in the overall weight distribution of a wheel, tire or brake disc to cause this shaking problem. (just a few grams in fact)
This has happened to me more times than I care to remember, because I'm always changing out the tire and wheel combos on my cars. (I get bored with the same look)
+1 to the guy that said it's annoying.