When you think about regular auto servicing, you tend to think about brakes, oil change, transmission and engine updates, but you may be missing a significant piece of the puzzle. While all of the aforementioned areas need regular attention if you are to maintain your car, you should also consider servicing your wheels and tyres. Why is this just as important?
A Complex Balance
As the four wheels fitted to your car endure a lot of wear and tear, it's crucial that they are properly set up, mated with the tyres correctly and frequently rechecked. If you remember when you bought a set of tyres last, you may recall that the technician took a long time to ensure that everything was balanced properly and that the wheels were tracking in the right direction before you set off. This is crucial if you want to get full value for money out of that expensive set of tyres, but without this type of alignment you're likely to spend more money on fuel as well, as your car would not be moving down the road correctly.
Three Major Alignments
When any wheel and tyre combination is presented to the road it should never be perfectly square or at right angles. It needs to have a certain amount of toe angle either inward or outward to ensure that you get a uniform rate of tread wear across all the covers.
Likewise, the wheel and tyre combo should never sit at the perfect 90° to the horizontal, once again to get better performance. In short, it should lean slightly inward at the top point, known in the trade as negative camber, so that the tread pattern on the tyre does not wear excessively on the outer or inner edges. Very occasionally, a wheel and tyre will be angled the other way (positive camber), but the technician will always rely on computerised settings to get the calculations right.
There's even more adjustment to be made to make sure that the wheels are correctly attached to the steering mechanism. This will require an adjustment to the arms to connect the wheels to the rack and column, so the axis of steering is always correct. This adjustment will allow the wheels to be presented properly to the road when the vehicle is being manoeuvred.
The Need to Recheck
You may think that everything was fine once the technician had made those initial adjustments and sent you on your way, but in the real world it's not so simple. Whenever you drive over a pothole or inadvertently bump against a curb these delicate adjustments can fall out of true. While each incident may only represent a small modification, over time you will find that the entire geometry is in need of sizeable adjustments. This is why it's important for you to take your vehicle in for a mechanic to service the wheels as well, so you don't spend money needlessly due to poor alignment.