Diagnosing Uneven Front Tire Wear

Tags: Suspension

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front tire wear problemA friend asks why they are having problems with their new front tires. It seems that after about 18 months of driving on a new set of tires the set on their front wheels are wearing out much faster than the rear. During that time they have had some parts changed on their front suspension including a front stabilizer bar bushing on the drivers side and just recently noticed that the steering wheel is rotated a small amount to the right when they drive straight down the road.

This is a pretty common problem with many vehicles. Car manufacturers build their suspensions to allow for reasonable operation even when there are things wrong with the suspension. In addition if you have power steering the car will not likely pull to one side or the other on a fresh set of tires unless there is something seriously wrong with a part or your alignment settings.

The normal wear pattern for a vehicle that has a good alignment and all of its parts working is inner wear on the front tires and even wear on the rear tires.

Inner wear on the front tires is caused by a slight toe in condition. This is where if you are looking at your front tires from above the front tips of the tires will point in towards the engine slightly to allow easier turning and control by the driver. When the tires are set to point in at each other this will cause more wear on the inner edge of the tire.

Rotating your tires from front to rear will extend the life of your tires by reducing the amount of wear on the inner edge. The wear will still occur but when the front tires are placed on the rear of the car it lets the tire wear off more of the tire evenly. Rear tires that are placed on the front and didn’t have toe wear will then get the inner edge worn down. And you go back and forth until the tires have been worn out evenly and you need a new set.

When you see a single tire with uneven wear it normally means that there is a suspension problem directly associated with that wheel.

Front tires are more susceptible to suspension problems because rear tires are always in a fixed position. Front tires have to handle all of the turning and to do so there are a number of parts that keep the wheels in correct position when going straight or when making turns.

Because only a single bushing was replaced on the drives side of the vehicle there was probably an uneven condition put into the suspension with one new and one older bushing working together.

Even though the alignment technician can align the vehicle to proper settings the two bushings working together as the vehicle is placed under the stress of driving down the road at 50 miles an hour and also taking turns will put the vehicle out of alignment during operation.

This can be a difficult diagnosis and wouldn’t normally be possible without the vehicle repair history. It is likely that they would go through a number of sets of tires thinking that they could never get the car to work correctly and then be disgusted with their vehicle.

The decision to save $40 and not have the bushings replaced as a set was a really bad one.

Remember when you are replacing parts on your vehicle you should do it in sets.

If you are changing brake pads then replace the front and rear sets at the same time even if you have more life on the rear pads. Rear pads normally last longer than the front because that is how they are designed.

If you are replacing tires you want to replace all of them at the same time or move your best set to the rear and put new ones on the front.

When you replace shocks and struts replace all four at the same time.

When you replace suspension bushings you should replace the front and rear as sets. Never work on the left or right independently.





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