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Pierre Bissonnette
pierrebissonnettejr@sympatico.ca
March 12, 2010
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2008 Buick Enclave Front Suspension
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Suspension
Be Sure to Verify First
Determining what is wrong with the suspension is sometimes a tricky job. Many items need to be checked out first before you can start the repair. We’re going to go over a few of them here.
Tires play a big part in suspension and now because it’s winter, we’ll concentrate on winter tires. They aren’t necessary by law in every province, but they are a great asset in the cold and snow. A lot of people are under the misconception that winter tires are good forever—this is simply not so. They wear out just like your regular tires! A regular 4-season tire is made of “hard” rubber because the asphalt is usually warmer so it doesn’t wear as fast. With winter tires, you’re driving on ice, snow and cold asphalt, so they’re made of “softer” rubber and if you drive with them on in the summer, they wear down quite quickly. You must measure the thickness of the snow tire—it’s about 9/32-inch thick when new. When you check the tire it could be worn in the middle or just on the side, and this tells you a lot about the suspension. Tire wear will happen if the alignment is off. And we mustn’t forget the TPMS… you need to check to see if that light is “off” before you start working on the vehicle.
Enter wheels…
People may also have two sets of wheels for their tires—one for the regular tires and one for the winters. You must be careful, as not all wheels are compatible with TPMS, especially the lower-priced steel wheels for winter tires. If this is the case, the TPMS light will be on when the vehicle arrives in your repair shop. If you go ahead with suspension repairs at this point, you will disable the system!
Japanese and some domestic vehicles have a wishbone suspension and there is a specific way of checking the lower ball joints on these particular models. You need to refer to the manufacturers’ specifications for this repair because if you check like you do for a regular front-wheel drive car, you will not detect the lower ball joint wear.
Elliott suspension (Type A)
Suppose the vehicle has an Elliott suspension (Type A) rear wheel drive… in this case, you must take the weight off the tires in order to check the lower ball joint. In other words, lift the vehicle from underneath the lower control arm close to the ball joint. Some manufacturers will ask you to check for radial play (l-r), some will ask you to check the axial play (up and down). This must be checked with a dial indicator. You need to also make sure that the wheel bearing is not loose. Again, refer to your manufacturers’ specs.
Be sure the wheels are hanging down when you check out the McPherson strut and the radial play. Don’t forget the upper strut bearing as it could be loose or it could be seized and when it is seized it can look like a defective rack and pinion, but the only thing wrong is the upper bearing.
Greaseable?
Remember, if the vehicle is greaseable it should be done before you inspect the front end. Be sure to check the inner and outer tie rod ends while the vehicle weight is on the tire. Then watch to see if it moves while you turn the steering, and, for goodness sake, do not check them with a pry bar—this will cause play. If the vehicle is equipped with an idler arm, use the same procedure but check manufacturer’s tolerances.
Check the steering shaft to see that it is not loose in the column… if it is, you will hear a clicking noise. You also need to inspect the u-joint as it could be seized (rack & pinion unit only). Be sure to take a good look at the stabilizer link/bar as this is a very high-wear item. And, don’t overlook the rear suspension; independent rear suspensions can have ball joints, outer tie rod ends, stabilizer links, and bushings. As you know, when aligning a four-wheel drive vehicle with independent rear suspension, you must start by setting the rear camber, if possible, and the rear toe, then proceed with the front wheels.
Pierre Bissonnette was the technical instructor for a major aftermarket manufacturer. He holds a teaching certificate in andragogy – which is the art and science of helping adults, whose general education has been cut short, in their learning process.
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