Re: Worn ball joints

[Tom Harais <tjhemh@domain.elided>]

Howard:

You couldn't be more right!

Look at any American car from the seventies (except for maybe Corvettes) 
with the front wheels turned sharply either way. You'll note that they seem
to have a great amount of "toe-in" at that point, with the wheel on the
opposite side from the direction of the turn cutting "in" much sharper than
that on the outside. In addition, there is usually some very funny camber
angles involved (resulting for the geometric process of turning the wheels
around a given steering axis inclination - or caster- and camber
combination and a steep camber introduced by the body roll and suspension
travel in that turn) to the point that the wheel on the outside of the turn
looks like it is about to "roll under" the body of the car. I always
assumed that the cars were engineered this way because it was the "safest"
in a hard turn manuever by an inexperienced driver.

The result is severe "understeer" which is considered the safest for a
driver not  schooled in driving technique. It means the front end tends to
"plow" straight ahead through the turn as compared to oversteer where the
front end goes where it's pointed but the back end will probably swing out
wildly, resulting in a "spinout". '70's Porsches were considered "unsafe"
because of their tendancy to oversteer with the engine wheight to the rear
as it was. The only way to handle the oversteer is to do the opposite of
what most people would instinctively do in a panic turn and that is stay
away from the break and step on the gas at the apex of the turn so that the
rear wheels "push" around the turn rather than having the rear end slide
around and come out in front of the car (a spinout).

Also everyday "proof" of your comment about tire "scrub": I have noticed,
in the summer when I turn into my driveway with the Scout and keep turning
across that concrete to park the Scout in the side yard that it leaves a
rubber "track" all the way from the street and across the driveway on the
most heavily outside front tire. Although other cars making an arc across
my driveway will leave similar tracks, they are never near as heavy as
those left by the Scout. And yes, it's a lot of rubber compared to what a
little positive camber might "scrub" when going straight ahead.

In fact, if the camber where the wheel were not "flat" on the road was hard
on tires, we'd see tire problems on all the old Ford "I-beam" suspensions
as well as on the old VWs, Porsches and Corvairs with "swing axles". Have
you ever looked at how much camber change there is on the front wheels of a
Ford truck when it oscillates up and down on the freeway? The tires go from
flat to tilted in on the "upstroke" to tilted out on the down and so on.

Tom H.