Time to replace struts?


#1

Are there simple ways to tell if struts need replacing? I read somewhere if you’re over 80,000 miles you’re due. Others had higher estimates. It’s not like shocks where you could watch the bounce.


#2

Actually, they are just like shocks in that respect. You can push down hard and see the reaction. And, they can last many miles, or only a few depending on how hard they have to work. Someone driving on smooth highways with a light car will get great life out of them. Someone driving a heavy car/truck over rough roads will have them fail quickly.

A better way to tell is try a speed bump in a parking lot. Does it rebound and stay there with at most 1-1/2 a rebounds, or continue to bounce. If it continues to bounce, you need new ones.


#3

Frankly they are more difficult to tell by bouncing today. Different cars will bounce different. If someone, like your mechanic, is very familiar with what it should feel like, then they can use the bounce test as part of their examination, but I would not count on it.

Certainly they may be worn at 80,000 miles and if I had that mileage and I was not sure, maybe it just did not feel tight any more, I would replace them. Consider this, if you are going to keep the car much longer, you are going to replace them so why not do it now.


#4

They can be tested the same way, but I agree that it is harder to tell. Most of the newer cars have a suspension set up in such a way that the struts aren’t the only thing controlling bounce, jounce, and roll. With the lateral links, anti-sway bar, and other various parts, simply kneeling down on the plastic bumper cover isn’t a full proof way. So, I can give some tips…
Check to see if they are leaking. A wet strut is not leaking. A strut that has oil running down the side is leaking.
Don’t confuse noises with a bad strut. Fords were famous for strut bearings (tee creaking and groaning while turning), The GM’s were famous for lower control arm bushings, and the asian vehicles were famous for the strut tops (insulators). It really bothers me when some one comes out with an entire new suspension when they only needed one part. However, if you do one side, do them both, and if you want to keep the car for a long period of time and feel better about replacing the strut, as Mr. Meehan said, by all means, go for it.
My car has 168k on it, with original struts. I agree with hallkbrds, alot of the wear is factored by the vehicle’s driving route. City cars will eat sruts, highway cars don’t seem to be that hard on them.
Keep this in mind though, Stuts and ‘shocks’ are NOT shock absorbers. The springs are. What we know as shocks and struts are actually ‘dampeners’, as they dampen the cyclic rate of bouncing. That being said, don’t ignore the springs. I have had to replace coil springs that have become weak over time and loads, when the struts were ok.


#5

As others have said-the answer is completely dependent on the roads the car has travelled and the type of car. A BMW 3 series that has gone 100K miles and a Chevrolet Cavalier that has gone 100K miles are on different planets for strut/shock wear with all else equal for example.

As for the bounce test-it’s pretty useless unless you’re driving an old American land yacht.


#6

I would inspect tires for cupping and other problems and speed humps/calmings.

The bounce test on strut vehicles does not work.


#7

The first thing to do is a visual inspection. Pull up the dust boot on the strut to determine if the strut is leaking oil. This will appear as a lot of dust/oil accumulated on the outside of the strut. This is one indication that the struts are worn.

The next is the bounce test. Go to each corner of the vehicle and start pushing down and releasing until get the that corner to starts bouncing up and down in a rythmic manner. Then release that corner. That corner of the vehicle should rebound up and then stop. If the corner continues to bounce up and down a couple of times after releasing it, it’s a pretty good indication that strut is worn.

Tester