This month, we’re going to have some Nissans on the lift addressing suspension noises and brake complaints. At first, you may not think these systems are closely related, but when it comes to noise and vibration complaints, you don’t want to be looking at one without considering the other. Before we get too deep into the nuts and bolts, we have to start at the beginning. And that’s at the service desk.
While we all enjoy the sounds that our customers make while trying to emulate the abnormal noises being emitted from their vehicle, the best way to find the problem is to go on a road test with the customer. Many times, things like a wheel bearing noise, long brake pedal travel and struts that can no longer dampen the spring happen gradually and the driver will become used to hearing the noise or the way the brakes or struts feel. Often, just pointing out the problem will be the first step to some profitable work. This isn’t upselling the job; our clients expect and appreciate that we recommend needed maintenance — it’s part of providing quality service.
The modern Nissan, like so many cars today, uses a simple suspension system that shouldn’t present much of a challenge. But there are some issues that will give even experienced techs some problems. Having driven the car with or without the client, the tech should have a good idea of where the problem is located. We’ll often have cars dropped off with a note saying, “struts are making noise.” Don’t let any uninformed comment send you down the wrong path.
Common Problems
The most frequent suspension and steering system-related problems are noise-related, with knocking and squeaking at the top of the list. Other complaints include poor handling; tire wear, drifting or pulling; and vibration issues.
As an example, we’ll look at a Sentra with 120,000 miles that was brought in with a customer complaining of squeaking and knocking noises. We were lucky with this one: A push and lift on the left-front wheel well revealed the distinctive up and down “bed spring” squeak. And, a quick drive on a road in poor condition revealed the knock. But, after many years of using the push-and-lift method to help determine suspension noises, we are now using a rocking method that seems better at picking up the noises that result when the suspension becomes unloaded on the road.
On the Sentra, our experience told us that this type of squeak is often the result of a ball joint or tie rod end that has a damaged boot, which allows the lubricant to escape, and dirt and moisture to get in. The resulting rust tightens up the joint and results in the noise.
The knocking noise sounded like the familiar problem of loose sway bar links or bushings that mount the sway bar to the chassis. This problem is often misdiagnosed; it takes only the slightest amount of play in these components to result in big noises. This is one of those items that is often overlooked and can result in a bad situation where struts have been replaced but the noise persists. Needless to say, the customer isn’t pleased to be presented with a sizeable bill, only to hear what he believes to be the same noise on the drive home.
