I just bought new tires for my Sentra which has.

Tiny
ANONYMOUS
  • MEMBER
  • 2008 NISSAN SENTRA
  • 63,000 MILES
I just bought new tires for my Sentra which has been an excellent car so far. The Goodyear dealer says it needs an alignment (which I understand.) They also say they need to put "camber adjustment kit" on the car to adjust the camber. The Nissan dealer says it shouldn't need any such thing unless it has been wrecked. The car has not been wrecked and it in great shape. Who is right? Who can I trust?
Tuesday, October 30th, 2012 AT 10:05 PM

1 Reply

Tiny
CARADIODOC
  • EXPERT
For decades all cars had adjustments for "camber" and "caster". In the '70s Ford found out they could save money by eliminating the caster adjustment, then in the '80s with their "killer cars", the Escort and Tempo, they even left the very important camber adjustment off. They made the camber REAL high, (that's the outward tilt of the wheel as viewed from in front), ... I mean REAL REAL high so the car rode smoothly on the highway compared to other cars so they sold a pile of the little disasters. What they didn't want you to know until after you bought it was it chewed the tires off in about 15,000 miles.

Since then some other manufacturers, mostly Japanese, have also left camber adjustments off so you get what you got and hope it's good enough. No alignment mechanic is ever happy with "good enough", especially when he is involved with warrantying new tires.

There is a compromise between the two stories you're getting. First of all, you don't automatically need an alignment just because you got new tires. If you "need" an alignment with new tires, you needed it before too with the old tires. New tires do not change the alignment. I preferred to align cars with the old tires so I could "read" their wear patterns. There are three things to consider. The car must not pull left or right on the highway when you let go of the steering wheel. You can tell that. The steering wheel must be straight when you're traveling straight. You can tell that. When either of those two things change, something has changed that changed the alignment and it's usually dangerously worn parts. Tire wear must be smooth across the tread and the same depth on both edges. No one can tell that with new tires. It is very possible for the first two to be correct and still be out of alignment. On the other hand, a bad tire can cause a pull, AND you may have to tug on the steering wheel to make the car go straight. That is not the same as an off-center steering wheel but it can be hard to tell the difference.

Neither story you got is entirely correct. If something is bent, as in from a crash or hitting a curb, those camber kits are not going to be the answer. Bent parts must be replaced to restore the steering and suspension systems to their proper geometry. That geometry is critical for proper handling AND proper braking. While the camber kit might get camber back in specs, it won't address the underlying bent parts or the incorrect and unequal side-to-side geometry. The guy at the dealership is saying the cars are built so precisely on the assembly lines that alignment adjustments aren't needed. That's fine when all he sees are relatively new cars. Why then years ago did we do tune-ups which always included making a series of adjustments? It's because things change. Your tire store people are assuming things have changed, but perhaps they didn't, ... Yet. The compromise should be the camber kits are installed only if they're needed.

Your car is a uni-body design with no steel frame. That design is made up of rolled-up and formed sheet metal and is much stronger and lighter than the old steel frames of decades ago, until they take enough potholes to cause that sheet metal to sag and bend or until they get rusty. NO car is going to stay exactly as it was built. Much more important is the fact that springs get weak and sag with age. The guys at your tire store will have a small book showing every car model, what the front and rear height measurements must be, and where to take those measurements. When ride height is wrong, the entire suspension geometry is wrong. Camber can still be adjusted so the numbers on the alignment computer's screen are in specs, (green), but you can still have poor tire wear. Those numbers only represent a car that is standing still on the hoist, not one that's moving up and down as you go down the road. If ride height is within the acceptable range, AND camber is within specs, AND camber is nearly equal on both sides, with the left side being a little higher positive, you don't need the camber kits. (Camber makes that tire want to pull in the direction it's leaning. We normally want the left one to be tipped out on top a little more than the right one so the tiny pull will offset roads slanted to the right so rain will run off).

The ride height can be expected to drop as the car ages. If it's out-of-specs some mechanics will still take your money and align the car with good-looking numbers on the printout, but the conscientious thing to do is replace the coil springs, (or simply adjust the torsion bar springs on the vehicles that use them), THEN set the alignment. Of course he knows he's going to get blamed for trying to sell you more parts than you were expecting, so many mechanics won't even check the ride height. They'll just do the best alignment they can and hope you don't remember them when the tires wear out sooner than normal.

So the bottom line is:

1. If ride height isn't correct, you can still have accelerated tire wear regardless if they install the camber kits.
2. Camber kits provide a means of adjusting camber if it wasn't provided by the manufacturer. The kit for one wheel is not needed at this time if camber on the wheel is correct, but the acceptable range is pretty broad and most conscientious mechanics aren't satisfied with "good enough". We want to be able to adjust both wheels to nearly perfect.
3. Camber WILL need to be adjusted at some point and the mechanic is planning for that. It takes time to set the equipment up on the car and calibrate the alignment sensors, then, once the initial readings are taken, if it is determined camber has to be adjusted, he has to tear down everything he set up on that wheel, pull things apart to install the kit, then start all over again with the setup. Two setups takes a lot longer than if he just put the kits in first, then began the alignment.
4. Every mechanic hates telling customers they need more parts after they gave the original repair estimate. To avoid that, they will often include all of the possibilities in the estimate in case those things are needed. With a car as new as yours, they may hand you a final bill less than expected, and tell you one or both kits turned out to be not needed. They also know those kits will be needed at some point and they would like to be the ones to sell them to you. The next time though you have to remember those kits are already in there and won't be needed again.
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Tuesday, October 30th, 2012 AT 11:25 PM

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