Was told this a way to check for idler and balljoint wear. Lift one side leaving opposite wheel on ground, then try to sterr the raised wheel, adn check up and down motion.

And there should be NO motion.??

Not even a little up and down and bit as you try to steer it? How can I tell if it's dangerous to run tthe car over 1200 miles of highway? Thnx.

when doing the up and down motion, you will feel your wheel bearing play. The only way you would know if your b/j's were shot is if you could see the play while moving it. Jack the car up oon a level surface by the frame. let the wheel hang with enough space to fit a long sturdy pole underneath. With pole lift up on wheel. feel with your hand on the wheel and someone else watching the upper joint. Then put a jack underneath the lower control arm and drop the car on it. Repeat test. If you feel movement(or see it) in the tire you've got a worn joint. Also make sure the initial play isn't the tire flexing.

Gene,
Try this,jack up both sides and set on stands.To check the steering linkage,have a helper grasp the tire and wiggle the steering back and forth rapidly.Get a good look at the tie rods,idler arm and center link any dangerous play will be visable and if you grab the suspected joint you'll feel it as well.Then to check the ball joints, With the car still on stands set a floor jack under the LCA under the spring pocket.Jack up slightly on the LCA just enough to load the suspension ( being carefull that car doesn't shift off the stands)
Now,have helper grasp the tire at 6 and 12 oclock positions and wiggle up and down.Watch each BJ as
this is done, any play in the ball joint will be visable.Repeat on the opposite side.If there is any excessive bearing play just snug it up temporarily.Moog makes a dial indicator just for this but for your purpase a good flashlite look at each joint will do.

Great instructions 71350SS! Thanks to both of you.

Gene, the way I check the ball joints are to put the jack under the LCA and lift until the wheel is off the ground, then use a long pipe or 2x4 and put under the wheel, have a helper lift up and let go a few times under the wheel on what ever lever you use and then you can look at the ball joints,(w/ flashlight) and look for movement between spindle and control arm. Any play is a bad ball joint.
The spring should be loaded and not hanging to test on these cars. Cars w/ springs on top of upper control arm hang. (Mustangs and Falcons)
I check the steering linkage by jacking only one wheel up and then move the wheel by hand at 3:00 and 9:00 and go back and forth. Look at the tierod end stud and it should have no wiggling movement. Then look at the idler arm movement. I say a little idler arm movement up and down while moving wheel back and forth is normal. Excessive is time to replace.
With the wheel up grab the wheel at 12:00 and 6:00 and wiggle in and out to check the wheel bearing play. Again a little is OK.
Looking forward to seeing you again. Have a safe trip.

A little is OK, I hope! thanx again guys.

At the state-run inspection facilities here in NJ, the front end was checked every year when the car was presented for it's yearly inspection. You would proceed to a position where two jacks would lift the front end off the ground while an inspector would rock the front wheels looking for too much "play" in the steering components. Any play in the center link, idler arm or wheel bearings would be evident immediately and you would fail. The inspection wouldn't catch every difficiency, but it helped.