Thanks for the addition, LINCMISN431. There's more to the story. I will admit I never worked on this model, but I was the suspension and alignment specialist for seven years in the '80s at a mass merchandiser's auto shop, then at a very nice family-owned Chrysler dealership for ten years, until 1999. At the first job, I got a REAL lot of experience on Ford's front-wheel-drive cars. We called them "killer cars" because of the very high number that came in on tow trucks after the outer tie rod ends separated, leading to loss of control and crashes.
The first problem had to do with the extremely terrible alignment settings. The first of the three main angles is "camber". That is the inward or outward tilt of the wheel, as viewed from in front of the car. Perfectly straight up and down is "0.00 degrees". If you can imagine the wheel laying flat on its side, that would be "90.00 degrees". Most cars call for around 0.25 to 0.75 degrees for best tire wear and handling. Anything higher than that will start to cause excessive wear to the outer edge of the tire, but it isn't high enough that you can see it on the car.
On the '80's Escorts and Tempos, the engineers set the front camber at 2 7/16 degrees! As a further insult, they couldn't be bothered to build in an adjustment for camber. We had never seen that cheapness before in the history of passenger cars. There were some attempts from the aftermarket companies to design repairs for these cars, but ultimately, none of them worked on the front. What no salesman would ever tell you is if you were real lucky, a pair of tires would last for 15,000 miles. If you complained too much, you were told you weren't rotating the tires often enough.
Related to that rotating of tires, the rear ones were tipped in a real lot. Those cars reminded us of new-born horses with their legs going in all the wrong directions. On the highway, it was real easy to see something was wrong when you passed one of those cars. After they stopped production of those models, a Ford trainer finally admitted it was done to make the cars ride much smoother than those of their competitors, by riding on the tiny edges of the tires. They didn't care that you had to keep on buying tires. By that time they had sold a pile of those cars.
The aftermarket industry came up with a wedge kit that allowed us to stand the rear tires up straighter. No alignment specialist can sleep at night knowing he let a car go with camber adjustments that would tear up the tires. It's in our nature to want to fix the design problems. Unfortunately there was no practical way to fix front camber. A lot of tire stores refused to provide a mileage warranty for their tires when they new they were going on an Escort or Tempo.
The next problem had to do with Ford's use of "rubber-bonded-sockets" for their lower ball joints and outer tie rod ends. No other manufacturer in the world has ever used this terrible design. The ball was dropped into a socket, then it was filled with molten rubber to glue those parts together. With every turn of the steering wheel, that rubber had to flex until it finally tore loose. Depending on which one separated first, you'd lose steering control and head into the ditch or into oncoming traffic, hence, the term, "killer cars". At the shop I worked at in the '80s, we got our shipment of parts in every Wednesday. We typically got a dozen tie rod ends and ball joints for GM products, a half dozen for Chryslers, and two to four parts for imports. Every week we got 44 outer tie rod ends for Escorts and Tempos, and those were sold and we had to buy more locally by Saturday. I got so good at replacing those that I could do two in five minutes, without even removing the wheels.
Related to this is camber is what affects which way the car pulls on a straight road when you let go of the steering wheel. In its most basic description, a tire wants to roll in the direction it's leaning, so camber must be equal on both front tires so their pulls offset each other. Since these cars had no adjustments for camber, how were we to solve a pulling problem? A friend who was the alignment specialist at the local Ford dealership explained how he did it. If a car always pulled to the right, he would disconnect the outer tie rod ends, turn the steering system to the left, then reconnect those tie rod ends. When the steering wheel was turned straight, it put those outer tie rod ends in a twist that tried to pull the steering system to the left. That was like adding a rubber bungee strap to the steering linkage to correct the problem. Now, since the tie rod ends were already stressed and twisting to the left, turning fully to the right twisted them even more than they were expected to twist. That further reduced their short life expectancy. Doing this was a cobble job, but it solved the customer's immediate complaint of a pull.
Every aftermarket supplier produced replacement outer tie rod ends for these cars of the same design as every other manufacturer had been using since forever. Another Ford innovation from the mid 1970s was to leave the grease fittings off their ball joints and tie rod ends. At a nickel a piece, leave four off each car, and you save four million nickels on a million cars. This was huge for their profits. If a worker can find a way to save a penny on the cost of building a car, he is likely to earn a promotion. It is such a big deal when you consider that applies to every car they build. Imagine the savings when they left those grease fittings off. Now, with the higher-quality aftermarket replacement parts, you have to remember to tell the mechanic to grease those parts as part of the normal oil change service, otherwise they knew to not bother looking for them on those models.
Now to address your model, camber is not adjustable on the front or the rear, so you're stuck with what you have. The car is going to follow the tire with the most weight on it. Most of the time that will be the two right tires because roads lean to the right so water runs off, but when you drive over bumps, or when the tilt changes, like at intersections, the front or rear can suddenly follow the other tire. When the two tires on an axle are pulling in wildly-different directions, you're going to feel that as a lack of "predictability". You can't anticipate how the car is going to react under certain conditions.
The only thing that can be aligned on your model is "toe". That is the direction each wheel is steering when the steering wheel is straight ahead. All alignment computers for the last 30 years have us set the rear wheels perfectly parallel to the car first, they have us set the front wheels to be perfectly parallel to the rear wheels. That last step assures the steering wheel will be straight even if the rear ones are off a little, which is not uncommon.
There ARE camber adjustment kits available from the aftermarket suppliers, but given the design of your suspension system, it is not obvious to me how these shims are installed. They look like they are meant to shift the positions of the upper strut mounts, but that would cause the front coil springs to rub on the body sheet metal, and moving the rear struts won't change rear camber. It looks like these shims need to be installed behind the wheel bearings, and that would be a really big, time-consuming job that you'd only want to do once.
The better suspect, especially given the age of your car, is sagged coil springs. Suspension ride height is a major factor in maintaining the correct geometry of all the parts, and the motions the wheels go through as the car bounces up and down on the road. If ride height is not correct, accelerated tire wear WILL result, even when all the numbers look perfect on the alignment computer. Those numbers only apply to a static car, meaning it's standing still on the hoist. Every tire and alignment shop has a small book that lists every car model and year, what the front and rear height specs are, and where to take those measurements. Most of us tend to overlook that step, especially when aligning relatively new cars, but when trying to solve repeated, elusive handling or tire wear problems, measuring and correcting ride height usually solves the problem.
I would start with an alignment, and ask to have the height measurements listed on the invoice. Also ask for a copy of the alignment printout. All alignment computers can make printouts. I always set a copy on the passenger front seat, with every setting I adjusted highlighted to show that it was out of specs before, and it is corrected now. If you post the numbers for front and rear caster, camber, toe, and ride height, I can interpret them for you. All alignment computers can be set to display the values to two places after the decimal point. A lot of shops set theirs to display only to the tenth of a degree because that makes it faster to get the numbers "in spec", or turns the numbers from red, (out of specs) to green (in specs). That was more than good enough for older rear-wheel-drive cars, but I found a lot of front-wheel-drive cars need exactly 0.06 degrees more camber on the left front wheel to offset "road crown", meaning that tilt to the right. If my computer was set to read to just the tenth of a degree, the numbers would be rounded off to show I had too much or too little offset when in fact, it was perfect. I wouldn't comment on how your specialist has his computer set, since he has obviously been having satisfactory results, but when I see it is set to read to the hundredth of a degree, it shows he is more concerned with perfection and your satisfaction, than with speed.
Be aware too that with most tv manufacturers and car manufacturers, when you attend their training classes, there is never anything wrong with the new, current designs. After more than 100 years, they finally have a car that has no design problems. It is always that old model that is no longer produced that had the problems. Every year we hear the same thing, and we know now that we won't hear about problems with the current 2018 models until five to ten years from now. All those previously-unknown problems can be solved, "by buying one of our current models".
Saturday, February 17th, 2018 AT 9:26 PM