Nope. The biggest thing with coil springs is they cause sagged ride height. Even beginning suspension and alignment specialists are not aware of the problems this causes. As a specialist myself, I get real excited, (in a bad way), when I see a lowered car or a raised truck. I had my boss's approval to refuse to work on any vehicle with purposely-altered ride height, simply because it can easily land us in a lawsuit, even when it had nothing to do with what I was repairing.
Your entire steering and suspension system is composed of many parts that are in a very specific geometric relationship with each other. That relationship is designed to keep the tires in precise orientations even though the suspension system is going up and down as the car bounces down the road. Sagged ride height allows the tires to move outside that desired limits of travel. That will result in accelerated tire wear even though the numbers on the alignment computer look perfect, and it reduces your steering response and increases stopping distances. When the other guy runs the red light and causes a crash, you can be sure his lawyer or insurance investigator will check your car for altered ride height and for any of a long list of non-approved modifications. They will use that to convince a jury that you were partly at fault for the crash because you were less able to avoid it, and they will be right.
Every tire and alignment shop has a large wall chart showing every car model, the allowable range of suspension ride height, and where those measurements must be taken. A conscientious mechanic will not align your car if the measurements are not within specs, because he knows doing so will still allow tire wear to occur too quickly, and he can't get the results you're paying for.
Struts can cause a variety of symptoms, but the most common is they simply fail to stop the car from bouncing excessively. That typically develops gradually over a long period of time, so car owners do not notice it. That can allow a tire to tip in and out on top a little, which it is designed to do, but when that is excessive, it reduces the amount of tread making contact with the road. You might feel that as having less "road feel", meaning the car is less responsive to steering and braking maneuvers. Struts and shock absorbers are designed to push together very easily so a tire hitting a bump can move up without pushing the entire car body up. That prevents a jarring ride. They are also designed to be much harder to pull apart. That reduces a tire's tendency to drop into a pot hole. When the damping action becomes weak from high mileage, tires will bounce up and drop down too easily. You will feel every bump in the road, and the car will bounce and rock more than normal.
Struts and shock absorbers can develop oil leaks too. It is that oil being constantly forced back and forth through a pair of tiny orifices that gives them their resistance to moving, and therefore, their damping ability. Oil leaks out when the upper seal is worn, or when the upper bushing is worn and allows the moving shaft to wobble sideways and away from that seal. Oil leaked out results in no damping action at all. You will get seasick from the constant real excessive bouncing. With a worn upper bushing, the shaft can move sideways. That allows the body of the strut to shift left and right a little, and that is what is supposed to be holding the wheel in perfect alignment. When that wear gets bad enough, you will feel and hear the clunking, and you will notice the need for constant steering correction as you drive. That is not a safety issue in terms of parts falling apart, but it definitely is a safety concern from the reduction in steering and braking control.
There is a third part involved with all front struts that causes just as many problems, but is harder to diagnose. That is the upper mount. That is the part that allows the coil spring to support the entire weight of that corner of the car, while allowing it to rotate as you turn the steering wheel. There is usually a small ball bearing assembly in there. Those mounts can bind from wear, dirt, or something broken. You might feel that as a binding or clunking when you turn the steering wheel, much more so when the car is standing still or moving slowly, as in when parking in a parking lot. The center hole can rust out too, allowing the wheel, again, to tip in and out on top too much. That wear is impossible to see or know about until the upper mount is removed during the strut replacement procedure. That is when we have to find you and tell you more parts are needed than we originally wrote the estimate for. We hate having to tell you that, and it is frustrating for customers too. You typically assume we're going to keep on finding things wrong as long as you have your wallet out. In truth, we would not be doing a conscientious job if we didn't find these things. To avoid having to tell you more parts are needed, I often included new upper mounts in my estimates in case they were found to be needed, but then I ran the risk of the shop down the road providing a lower initial estimate for the "same" repair, and I would lose the job.
There is one more variable important to this story. That is one of the major safety concerns your mechanic faces when replacing struts is the coil spring has to be compressed to allow it to be removed. That spring could have been supporting close to 2,000 pounds of weight on some vehicles, and it will be under that much pressure when we lift it off the strut. I have seen two get away and fly across the shop. One took out an eight-foot light fixture. The one that happened to me flew across the shop and out the door. It made so much noise, the office manager who was behind two closed doors came running to see what the excitement was all about. Fortunately it was just my pride that was wounded, but it shows the severe damage a spring under compression can do.
Getting back to coil springs for a minute, Honda and Ford did have some trouble with theirs breaking, mostly in the 1990's, and while the surprise could cause you to momentarily be in less-than-total-control, more trouble was caused if a sharp end of the broken coil tore a hole in the sidewall of the tire. If you look at your springs, you will see they have black paint on them. That is an anti-rust coating. Eventually you will see that coating has flaked off and the metal spring has started to rust. That is an indication we want to get those replaced before you DO have a torn tire.
All of these issues are addressed now with an assembly often referred to as a "Quick Strut". The aftermarket suspension parts industry does a really good job of designing parts that are an improved design or that address common failures we see over and over. Quick-Struts are the strut, coil spring, upper mount, rubber noise insulator, (when used, mainly on Chrysler products), and dust shield already assembled and ready to be installed on the car. No need for a strut compressor. No safety concern with flying springs. And a huge savings in time which translates to dollars for our customers. I suspect your mechanic is recommending these for your car, which is real easy to see is a better deal for both of you. He is also considering that your coil springs have been holding up the car for eleven years. It is time, not mileage, that causes springs to become weak.
Leakage from axle seals has to be seen to be evaluated. Replacing one can take as much as two hours on some cars, but once the strut is removed, the additional time to do a seal might be cut in half. We would typically make you aware of a leaking axle seal when we notice it during other service, but it is a judgement call as to whether it is bad enough to recommend immediate repair. It might not pay to go through that much work right now if it is going to take two hours per side, (although we know a leaking seal is only going to get worse, never better), but if the leakage is bad enough, now is the time to replace the seals when the job is already half done when the struts are being replaced.
So far you have only asked about the struts and seals. You have not included anything to suggest the mechanic has anything other than your best interest at heart. Be aware an alignment is necessary after replacing struts. The main alignment angle of concern is "camber", meaning how much the wheel is tipped in or out on top. That affects tire wear, pulling to one side, and to a less extent, braking power. On Chrysler and GM products, camber is adjusted by loosening the two lower strut mounting bolts, then shifting the wheel to the perfect setting. On GMs, one of the holes must be elongated to make it adjustable, and that takes more time, meaning more dollars. Quick Struts come with that hole already elongated to provide the adjustment.
Since I was a specialist at a very nice family-owned Chrysler dealership, I worked on a higher percentage of cars that were too new to have a lot of rust, and I had all the needed tools and parts right at hand. Once the car was on the hoist, I could replace a pair of struts in less than fifteen minutes. That sounds fast, but I did it over and over, including on many trade-in cars of other brands. Mechanics who are not alignment specialists will take a lot longer because they have to watch closer to know they did each step correctly. I took longer with the alignments than almost anyone else in the business because I was very picky with getting everything just perfect. "Good enough" is good enough for most cars, but I found it faster to take the time to get perfect results the first time rather than having to come back after the test-drive to readjust something.
Just guessing roughly off the top of my head, I suspect the entire repair you listed could take four to five hours. Each procedure will be listed in a "flat rate guide". That spells out the time it should take, and it will account for combined services. That means it will list a time to replace one axle seal. Two axle seals typically do not get twice the number of hours, and the time allowed will be cut by quite a bit when struts are being replaced at the same time. One thing to watch for is if they are charging you the two individual times, one for a strut and one for a seal, when they should be charging the reduced time for the seals. That is easy for newer service writers to overlook, but it is not easy to miss in the books.
Monday, December 5th, 2016 AT 6:16 PM