You must understand the engineers devoted thousands of hours to designing the geometric angles that are inter-related with the steering and suspension systems. You messed that all up when you altered the suspension ride height. As a former suspension and alignment specialist at a very nice family-owned Chrysler dealership, I had the owners' and service manager's blessings to refuse to align any raised truck or lowered car. They knew the importance of correct ride height, and they understood I could be leaving them open for future lawsuits if I worked on altered vehicles. That is why most reputable shops will not align your car now.
One of the biggest issues has to do with "scrub radius". That is an imaginary line drawn between the two steering pivot points, in your case, the lower ball joint and the upper strut mount. That line is designed to intersect the road surface at a very specific point midway across the tire's tread pattern. Wider wheels, deep offset wheels, and replacement tires with a different outer circumference also change scrub radius. The potential for a lawsuit is when the other guy runs a red light and causes a crash. His lawyer or insurance investigator will convince a jury that you were partly at fault because you were less-able to avoid the crash, and they will usually be right. By altering ride height, you've compromised all of those inter-related geometric angles, and those have compromised braking ability, handling, steering response, and even comfort, which leads to fatigue.
Be aware correct alignment adjustments account for only half of tire wear and handling issues. The other half comes from the changes the geometric angles go through as the car bounces up and down on the road. That is why a majority of passenger cars call for slightly positive "camber", meaning the front wheels lean out a little on top. With altered ride height on any vehicle with independent front suspension, you definitely will have accelerated tire wear even when the numbers on the alignment computer look perfect. For this reason, most tire stores will not give you a mileage warranty with new tires. This even applies to a few cars that are well-known to have severe design compromises that accentuate comfort while sacrificing tire wear. (Comfort on a test drive sells new cars. The miserable tire wear doesn't show up until after you've made a half dozen car payments).
As far as the vehicle itself, one of the most common mistakes competent do-it-yourselfers, and even inexperienced mechanics make is when you changed the ride height, you changed the angle of the lower control arm, which should be parallel to the ground. The simple fact its angle has changed means the rubber control arm bushings are now in a permanent twist, which will greatly reduce their life expectancy. This is even a problem when replacing suspension parts on any vehicle when that suspension is drooping from the vehicle hanging on a hoist. Proper procedure is to bounce the vehicle or drive it around the parking lot with the pivot bolts loose, so the suspension can settle, then tighten the bolts while the vehicle is sitting on the ground or a drive-on hoist. You won't be able to crawl under your car to do that now, but you might consider setting the car on four jack stands with those stands placed under the control arms, as far out as possible. That will keep the suspension up at its new ride height. At that point, loosen the control arm pivot bolts, then retighten them. That will let the bushings snap back to their at-rest position.
Now that the noise has been occurring for a while, look for "witness marks", meaning shiny spots where paint or rust has been worn off from something rubbing against it. In particular, check the half shafts for signs of contact with the lower control arms. Check the anti-sway bar links to see if they're hitting something. This will be lower down on the list of suspects since the studs are still close to their regular position, but you don't want to overlook anything.
There's three categories of things to look for. The most obvious one to most people is new parts were installed, so that is the place to start looking. Less-obvious is the changed orientation of the steering and suspension parts. That's where you have to look for parts interfering with each other that weren't previously. Typically the alignment specialist is concerned with the third category. That's worn parts, but with a twist in this case. While this is much less common, it is not unheard of for a ball joint to develop a worn spot that doesn't affect anything until the ball sits in a different orientation. That is what happens when ride height is changed. When you hit just the right bump in the road, the ball might rotate through a tight spot in the housing, then pop free. I can't tell you how many times I replaced a slightly sloppy ball joint only to be surprised at how really sloppy it was once it was removed.
Feel around the inside of the inner fender to see if something is hitting the coil spring. This will usually be attaching bolts or other hardware run through from the engine compartment. Due to the shape of the lower part of the spindle, the coil springs on a lot of cars do not simply rotate when you turn the steering system. The spring is offset from that scrub radius line I mentioned, so that spring moves around as it rotates. You may have to hit the magic combination of steering direction and compression / rebound from a bump in the road, to make the interference occur.
Since up to this point you haven't been able to identify the cause with the car standing still, consider looking for a tool called the "Chassis Ear". That is a set of six microphones, a switch box, and headphones. You clip the microphones to suspect parts, then switch between them while on a test-drive. I found the older model on eBay for $99.00, half of what the guys on the tool trucks used to charge. The microphones are wired and plugged into the switch box, so you have to be careful where you run those wires. One of the newer models uses wireless microphones, but it costs a lot more too. Be aware a lot of mechanics have never heard of this tool. Suspension specialists use it most often. You may be able to find one at an auto parts store that rents or borrows tools. In my city, they make you buy the tool, then you get a full refund when you take it back. If you choose to keep a tool, you still take the old one back, then they order or give you a brand new one.
Kasekenny mentioned this sounds like a spring issue. Binding upper strut mounts commonly cause a clunking noise when slowly turning the steering wheel, but due to normal vibration when driving, you will not hear that at highway speeds. For spring-related noises while driving, besides interference with other parts, look at the pockets the top and bottom of the spring sits in. There is usually a shaped channel the end is designed to fit into, and the end of the spring is at the end of that channel. If the spring isn't seated in the right orientation, it could walk back and forth, and since it's under high pressure, it will make a snapping noise when it moves.
I'll let you guys continue on. Anxious to learn what is causing the noise.
Tuesday, July 21st, 2020 AT 5:57 PM
