Vibration / shake after 60 mph, what else can cause this?

Some one didn't do a very good alignment. If it was done recently, you may won't to take it back. Unless you been hitting some major pot holes. Vibration that comes and goes like that is usually tire balance. Might want to have the suspension checked. But they should have done that before the alignment. You can't align a vehicle if it has bad tie rods, ball joints or struts.

Control arm bushings would have been my 1st guess.
Struts/shocks are a possibility. (the top mount bushing on the struts)
Get the tires balanced..... that can cause vibration.

Try rotating both front wheels to the back one at a time. If a tire has a bad belt; it may balanced but balancing does not eliminate a soft spot on the tire tread. By moving the tires to the back and road testing it after each side is done, you may be able to find the bad tire.

You have a lot of moving parts. A brake rotor could be out of balance, you can have a worn CV joint shaft, a hub bearing could be worn, driveshafts and U-joints can shake.

If you do find one wheel as a problem, have the tire dismounted and the wheel spun on the machine. You may have a bent rim and the tire may be good. Since the balance would help compensate for the vibration, it can mask the flattened spot on the rim. The tire will act like a shock absorber but ultimately the rim is not turning like it is round once weight is on it.

I would be interested in what you found.

You need to have someone look at it that is experienced in NVH (Noise, Vibration and Harshness). Front end vibrations can be caused by many things. Each possibility needs to be systematically eliminated to find the cause. Someone who is experienced in this can eliminate several possibilities by simply driving the vehicle...Did the tire shop even bother to road test it? I'll bet not!

Sometimes INTERNAL tire problems can cause a vibration that cannot be found (or eliminated as a possibility) by putting the tires on a balance machine. To eliminate this as a possibility, rotate the tires front-to-rear one side at a time then drive the vehicle to see if the vibration changes or "moves". If it does, then the tire that just got rotated to the rear is the problem.

Also, the vehicle can be run on a lift to see if the vibration can be duplicated in the shop. Many times, if the vibration is being caused by a drive axle or CV joint, it can be located by running the vehicle on a lift this way. In the case of 4-wheel drive vehicles, it will be necessary to engage the front axles to get them spinning on the lift.

The entire steering and suspension system should be checked for looseness in the tie rods, stabilizer links and frame bushings, control arm bushings, etc. Any looseness in any of these parts can cause vibrations at certain speeds.

I have also seen vibrations that act similar to a tire being out of balance that occurs when the brake rotors loose a balancing weight on some vehicles. This may or may not apply to your vehicle, (yours may not have balance weights in the rotors) but this type of vibration can usually also be verified by running the vehicle on a lift.

ball joints,tie rods,unbalanced tires. Many shops will offer a free alingment check when they check it most likely they will find the parts causeing the problem

Try replacing the end links to the front sway bar. The sway bar end link bushings may be worn and needs to be replaced, buy the sway bar end link kit with the urethane bushing. They last a life time and cost about $45.00 for both sides at Parts Source or Auto Zone and takes you less then 30 min to repalce both sides. Good Luck and keep me posted. Worn bushing to the sway bar, shocks and steering component will cause vibrations out on the highway.

Alignment has alot to do with the tires not shimmying.. Like zero toe setting. Loose componants like tie rod ends and the idler ar worn. You can ck for excess front end play by holding the front and back of the wheel and pushing and pulling on it, like rocking it. OR have someone rock the steering while you watch where the play is from underneath. By rocking I mean turn the steering wheel back and forth. Look at all th joints and pivot points for excess play, which is, movement not immediate to the rest of the steering system. Tire balance is very important. Wheel hop is a sign of a bad tire and it overtaxes the shock absorber. Shocks don't cause shimmy because they are a vertical movement controlA shimmy is lateral or side to side.Wheel balance weights must be spit. If a 2 oz. weight is needed to balance the tire, Oe once should be on the inside of the wheel and one ounce on the outside directly across from each outher.. Loose wheel brgs will cause shimmy, but they would not last long. Caster setting on the wheel alignment will also cause shimmy. Like on a shopping car. too much caster causes the wheel to start fluttering and is very hard on other componants. This may be why you have worn tie rod ends and a bad pitman arm. Worn control arm bushings and ball joints directly affect titre wear and can only be feltwhen the front end hits a dip and detected by side wear on the tire edges. Summary: replace the tie rod end and have the car aligned. Good Luck, -Ned_ sorry about the book

ball joint
control arm
shocks
brake rotor
and all your suspension parts have them check by your mechanic

have the steering rack checked for excess play, also have all the front end bushing checked, this is a common cause of this type of problem, it is the front end that is doing it, finding the worn part(s) is the job that needs to be done to correct this.

As for your shaking at highway speeds, providing your tires have been balanced properly, it's probably a u-joint. If you let off the gas when it's vibrating, and the vibration quits immediatly, it's a u-joint. If it doesn't, it's a tire or wheel.
The squeak is probably a shock, but that would be a guess.