When to replace struts
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Originally Posted by ram_man
If they aren't leaking or bouncing excessively and the mounts are in good shape do you bother replacing them?
Nope.
If they aren't leaking or bouncing excessively and the mounts are in good shape do you bother replacing them?
Nope.
Shocks and struts do eventually wear out, but there is no specific mileage interval they have to be replaced at.
You do not need to replace them if they are in good shape. Only replace them when they are blown/worn/leaking, or if you want to upgrade to high performance shocks.
You do not need to replace them if they are in good shape. Only replace them when they are blown/worn/leaking, or if you want to upgrade to high performance shocks.
Nick1994
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Depends on the car and the conditions they're driven.
I had an 04' VW that had original struts/shocks at 175k and was still pretty decent. Mostly highway and decent-ish roads.
My Camry has 236k miles on the original rear struts. Not much left to them anymore, but up until 220k they were fine. Fronts have about 115k mikes, they're still doing ok.
My Sonata had 107k on all original suspension, it drove/rode like absolute new.
But if any of these cars lived their lives on the streets that were full of potholes it would probably be a different story.
I had an 04' VW that had original struts/shocks at 175k and was still pretty decent. Mostly highway and decent-ish roads.
My Camry has 236k miles on the original rear struts. Not much left to them anymore, but up until 220k they were fine. Fronts have about 115k mikes, they're still doing ok.
My Sonata had 107k on all original suspension, it drove/rode like absolute new.
But if any of these cars lived their lives on the streets that were full of potholes it would probably be a different story.
Struts / shocks dampen spring movement by forcing oil through a valve in the body of the strut / shock.
Soooo, if the struts / shocks aren't leaking, they will still be able to dampen movement. The oil gets beat up over time, but the struts / shocks will still work.
NO oil, no damping ... leaking struts or shocks are the first step to completely blown, oil everywhere struts / shocks. Look for that car on the freeway with one wheel that is crazy bouncy.
Soooo, if the struts / shocks aren't leaking, they will still be able to dampen movement. The oil gets beat up over time, but the struts / shocks will still work.
NO oil, no damping ... leaking struts or shocks are the first step to completely blown, oil everywhere struts / shocks. Look for that car on the freeway with one wheel that is crazy bouncy.
Originally Posted by geeman789
Struts / shocks dampen spring movement by forcing oil through a valve in the body of the strut / shock.
Soooo, if the struts / shocks aren't leaking, they will still be able to dampen movement. The oil gets beat up over time, but the struts / shocks will still work.
Internal valves and seals can fail without the external seal failing. Its not automatic that a strut isn't failed just because external oil contamination isn't notable.
The 'problem' with shocks and struts is their deterioration is so gradual that one doesn't even notice it -- but its an absolute world of difference when the operator has the parts replaced or rents a vehicle derived from the same chassis family on a vacation and notices a dramatic difference in ride. And while maintainers occasionally have access to diagnostic equipment for many other components, equipment to test suspension damper components does not commonly exist, and testing would be far too labour intensive relative to just replacing the components.
I guess OEM's could engineer a standard artificial 'roadbump', and then measure the output waveform of such with a 3D accelerometer, equating it to a transfer function that incorporated an idealization of the mass-spring-damper components and calculating a damping gamma value accordingly. Or essentially whip up something similar with multiple accelerometers and some fancy math to do a real-time analysis of suspension components and trigger an "check suspension light" or code. But cars are already electrical/computer nightmares enough!
Struts / shocks dampen spring movement by forcing oil through a valve in the body of the strut / shock.
Soooo, if the struts / shocks aren't leaking, they will still be able to dampen movement. The oil gets beat up over time, but the struts / shocks will still work.
Internal valves and seals can fail without the external seal failing. Its not automatic that a strut isn't failed just because external oil contamination isn't notable.
The 'problem' with shocks and struts is their deterioration is so gradual that one doesn't even notice it -- but its an absolute world of difference when the operator has the parts replaced or rents a vehicle derived from the same chassis family on a vacation and notices a dramatic difference in ride. And while maintainers occasionally have access to diagnostic equipment for many other components, equipment to test suspension damper components does not commonly exist, and testing would be far too labour intensive relative to just replacing the components.
I guess OEM's could engineer a standard artificial 'roadbump', and then measure the output waveform of such with a 3D accelerometer, equating it to a transfer function that incorporated an idealization of the mass-spring-damper components and calculating a damping gamma value accordingly. Or essentially whip up something similar with multiple accelerometers and some fancy math to do a real-time analysis of suspension components and trigger an "check suspension light" or code. But cars are already electrical/computer nightmares enough!
If they're not leaking or rusting out, sure you can wait, but they are going to wear over tens of thousands of miles so I typically replace them every 50K mi. whether the bounce seems excessive or not, unless I'm soon to get rid of the vehicle and they're not terrible yet.
Things like bounce, that get gradually worse, aren't as night and day easy to compare until they're replaced, but don't cheap out and put generic Chinese brand struts on or else you may soon be worse off than you started. Go to a car forum for your particular make/model/generation and solicit opinions from fellow owners who have been through this already.
Keep in mind that if (assuming) you'll need an alignment, it can make sense to time the strut replacement along with another repair activity that makes an alignment prudent like worn suspension parts, a collision (even a bad pothole) causing an issue, or right before going to get new tires put on, so you're not paying for another alignment over and over (or else you bought an alignment package at higher cost to give you lifetime alignment but read the fine print for that).
Things like bounce, that get gradually worse, aren't as night and day easy to compare until they're replaced, but don't cheap out and put generic Chinese brand struts on or else you may soon be worse off than you started. Go to a car forum for your particular make/model/generation and solicit opinions from fellow owners who have been through this already.
Keep in mind that if (assuming) you'll need an alignment, it can make sense to time the strut replacement along with another repair activity that makes an alignment prudent like worn suspension parts, a collision (even a bad pothole) causing an issue, or right before going to get new tires put on, so you're not paying for another alignment over and over (or else you bought an alignment package at higher cost to give you lifetime alignment but read the fine print for that).
Originally Posted by ram_man
I kind of wondered this because some people say every 60k to replace them the manufacturers don't list a specific time frame ect. If they aren't leaking or bouncing excessively and the mounts are in good shape do you bother replacing them?
I bought my Jeep Grand Cherokee, 2010, with 68K on it. The whole suspension was totally shot. No leaking though, at least (for the suspension, anyways...)
That was commonly accepted as well past its life-span on the Jeep forums. It handled horribly. Scary under hard braking, in fact. My CX5 on the other hand, I drove to 106K miles, and its suspension was great. Same as they day I picked it up with 27K on the odometer.
Quality and good engineering matter a lot when it comes to component life. The answer will not be the same for every vehicle.
I kind of wondered this because some people say every 60k to replace them the manufacturers don't list a specific time frame ect. If they aren't leaking or bouncing excessively and the mounts are in good shape do you bother replacing them?
I bought my Jeep Grand Cherokee, 2010, with 68K on it. The whole suspension was totally shot. No leaking though, at least (for the suspension, anyways...)
That was commonly accepted as well past its life-span on the Jeep forums. It handled horribly. Scary under hard braking, in fact. My CX5 on the other hand, I drove to 106K miles, and its suspension was great. Same as they day I picked it up with 27K on the odometer.
Quality and good engineering matter a lot when it comes to component life. The answer will not be the same for every vehicle.
Would the strut include the coil spring? It'd be hard for me to pitch OE springs at ~60k only to replace them with aftermarket junk.
I would replace simply the shock as long as you can. When the time comes to replace the coil, get OE.
I would replace simply the shock as long as you can. When the time comes to replace the coil, get OE.
I'm not sure when the bounce test stopped being applicable but it seems like it stopped being useful long ago.
I usually go by forum recommendations. When I had my VW it was the word that the OEM struts were good for 40k. When I replaced at 120k there was not doubt that they were toast. Most forums indicate that Toyota struts are darn near lifetime and thus I'm in no rush to change on the wife's car. Mine, I'm thinking about just doing another set of quick struts, it's cheap money to check to see if it fixes the ride problems.
I just try hard to not worry about it. The roads are awful this time of year and about nothing will ride real well.
I usually go by forum recommendations. When I had my VW it was the word that the OEM struts were good for 40k. When I replaced at 120k there was not doubt that they were toast. Most forums indicate that Toyota struts are darn near lifetime and thus I'm in no rush to change on the wife's car. Mine, I'm thinking about just doing another set of quick struts, it's cheap money to check to see if it fixes the ride problems.
I just try hard to not worry about it. The roads are awful this time of year and about nothing will ride real well.
Originally Posted by Leo99
I replace them if they fail the bounce test or tires are wearing excessively. My old Rav4 went to the junkyard with almost 400k miles on the factory struts and they were still good. Struts are too expensive to change based on mileage.
I do it based on handling and dynamics, or obviously if it's leaking. The bounce test is pretty useless.
I replace them if they fail the bounce test or tires are wearing excessively. My old Rav4 went to the junkyard with almost 400k miles on the factory struts and they were still good. Struts are too expensive to change based on mileage.
I do it based on handling and dynamics, or obviously if it's leaking. The bounce test is pretty useless.
Originally Posted by ram_man
I kind of wondered this because some people say every 60k to replace them the manufacturers don't list a specific time frame ect. If they aren't leaking or bouncing excessively and the mounts are in good shape do you bother replacing them?
No .
I kind of wondered this because some people say every 60k to replace them the manufacturers don't list a specific time frame ect. If they aren't leaking or bouncing excessively and the mounts are in good shape do you bother replacing them?
No .
OVERKILL
$100 Site Donor 2021
It is going to depend on the vehicle and the conditions in which it is operated. Our 2002 Expedition was pretty hard on dampers and it was obvious when they were no longer doing their job, despite none of them leaking. I replaced them with RANCHO ones, but they were getting pretty tired by the time we sold the vehicle, despite having a small fraction of the mileage on them that the OEM Ford ones went. The Expedition, being big, heavy body-on-frame vehicle, would be quite demanding on dampers when compared to a much lighter unibody vehicle.
^^What Ws6 said above^^
I've read the bounce test is no longer applicable due to valve design.
I remember my car feeling "wallowy" so I bought good replacements. Old Volvo OE out, Sachs SporTourings in.
Both front struts were leaking smelly syrup.
One was 100% resistance free. One had some stiffness left.
I could barely feel any change with the new ones.
Odd.
I've read the bounce test is no longer applicable due to valve design.
I remember my car feeling "wallowy" so I bought good replacements. Old Volvo OE out, Sachs SporTourings in.
Both front struts were leaking smelly syrup.
One was 100% resistance free. One had some stiffness left.
I could barely feel any change with the new ones.
Odd.
The best easy test for strut / shock performance is the freeway expansion joint test. Observe the vehicles wheels from another vehicle as it goes over the expansion joint at highway speed. A decent shock will fully dampen the movement, with no extra bounce or shudder. A worn shock will let the wheel bounce another 1/2 cycle or so with some shudder. A blown strut will do nothing, and the wheel will oscillate thru multiple cycles after the initial hit, often for a few seconds or longer.
I have never seen a strut / shock that wasn't leaking oil badly lose all damping ability. Weaker yes, but not completely blown.
I have never seen a strut / shock that wasn't leaking oil badly lose all damping ability. Weaker yes, but not completely blown.
OVERKILL
$100 Site Donor 2021
Originally Posted by wdn
I changed the front and rear suspension parts (front struts, rear shocks) on my gen 1 Tundra TRD at 155,000 miles. The difference was like night and day. It drives like a new car now. The original ones were not leaking either.
That mirrors my experience with the Expedition.
I changed the front and rear suspension parts (front struts, rear shocks) on my gen 1 Tundra TRD at 155,000 miles. The difference was like night and day. It drives like a new car now. The original ones were not leaking either.
That mirrors my experience with the Expedition.
I replaced my 30 year old struts because they were making rubbing noises whenever i go over large speed bumps. They also rolled a lot but otherwise still comfortable with minimal floating. They however had missing bumpstops in the rear and the shock shaft was exposed to the elements, probably causing the shaft to have scratches and why the rubbing noise is appearing on full extension and compression. I replaced new struts and also added rubber bellows to them for further protection.
Curiously enough, corolla Ae101 steering rack rubber boots are a perfect fit on the struts, you just need to cut off the small diameter end.
Curiously enough, corolla Ae101 steering rack rubber boots are a perfect fit on the struts, you just need to cut off the small diameter end.
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