If your Peterbilt is slowly pulling to one side or sagging slightly as if it's the Titanic after it hit the iceberg, then you likely have a problem with your springs or suspension. One quick way to determine if that's the case is to do a ride height check. You'll be checking both front and rear suspensions by measuring each individual tire against the factory recommendations.
Determine the recommended factory ride heights for your model of Peterbilt truck. Each model has a slightly different height off the ground and finding out this information gives you a baseline reading to judge against. The recomended ride height can be found by contacting a Peterbilt dealer or an authorized repair shop.
Determine the correct place to measure the ride height. Peterbilt has a series of recommended spots where you should measure, depending on the type of vehicle and suspension. Measuring the height in the wrong spot will give you an inaccurate reading, making this test worthless.
Check to make sure the tires are filled to the factory recommended levels and that the truck is not unnaturally weighed down with cargo or large items inside the personal area of the truck. The goal is to have as optimum a situation as possible when you make the measurements.
Measure the distance from the recommended spot on the Peterbilt to the ground, using the measuring tape. Check each wheel, writing down the measurements as you go. A difference of more than 1 inch or so side-to-side or 3 inches or more off the recommended ride heights signals that there is likely a suspension problem with the vehicle.
Check the tire wear on all tires, giving special attention to the ones where the ride height appears to be off the recommended levels. Suspension issues can drastically affect tire wear, particularly on suspensions where toe is sensitive to changes in ride height.
