How can *I* test if rear shocks are good or not? (Mazda3)

[exdeath]

Originally posted by: boomerang

Most bump stops are not integral with the shocks. They're a rubber bumper on the car's structure that a suspension component will strike against. Yes, they can be broken. If they are, the suspension can compress farther than it should. Cars are designed to not have major damage should a bump stop be broken or damaged. They should still be replaced. This is not a major concern.

I'm going to take issue with what exdeath is saying. Worn out shocks or struts can get a car bouncing in such a manner that the handling is compromised to the point that the car will difficult to control. This naturally would be the biggest problem on the wheels that do the steering. It would be near impossible to have a mechanical failure of a strut. They act as both a suspension member and a shock absorber. The shock portion can wear out and the mechanical integrity is not compromised in the slightest.

True, but the way most people granny around, it's unlikely all but the most aggressive of drivers are going to encounter a handling error because of worn shocks, and those drivers are just as likely to cause collisions regardless of the state of the vehicle.

 

[hanoverphist]

Originally posted by: angry hampster

Originally posted by: exdeath

Not really. They don't do anything but dampen, they are non structural.

Struts on the other hand... yeah you could lose a wheel or something.

They're not structural, but they keep your wheels planted over uneven surfaces.

yup, rear shocks on my truck are bad, when i go on the overpass from the 202 to the 60 here there is an expansion joint in the road that is particularly deep and will toss the back end of my truck to the side if im going too fast. doesnt do that with good shocks. while the shacks arent structural, they are stabilizing

 

[PlasmaBomb]

Originally posted by: angry hampster
This is what bad shock bounce is like:

http://www.youtube.com/watch?v=MwBW15AO_Ag

It is extremely unsafe to have bad shocks. How many miles does your car have anyway? Shocks are a common repair between 50,000-100,000 miles.

:thumbsup:

 

[angry hampster]

Originally posted by: Marlin1975


Yea you might need them then if you have a lot of weight back there and have over 80k.

You can get Monroe shocks for $31 at Rockauto.com (5% coupon at fatwallet). They are easy to install.
If you plan on keeping the car at least 1+ year longer I would go for it. Even if you buy a repair manual you will be out less then $100.

Everyone has an anecdote. Shock wear can depend on a multitude of conditions.

 

[JEDI]

Originally posted by: JulesMaximus

Originally posted by: JEDI

Originally posted by: Marlin1975
OP What is the year, FULL make/model (like hatch/trunk) and how many miles.


Shocks can go bad as little as 30k or less or last 100k. So there is no set magic number but if you have over 60k and the can has a lot of uncontrolled bounce from the rear then it may be time. It could also be a shop trying to make some money off you as shocks are very easy and require much less labor then struts. i.e. easy money for them.

2005 Mazda3i automatic, 82k miles. it has a trunk.

hm.. i also have lots of stuff (~200pounds) in the trunk, most of witch i should remove. how much heavy weight continuously in the trunk would be needed to damage the shocks?

the repair shop said $300 to replace rear shocks. 🙁

You can probably buy the shocks yourself for under $100 for a pair. Rear shocks aren't expensive and they are easy to replace. Usually it's just 2 bolts per side. Just make sure you don't overtighten the bolts.

hm.. use a jack to lift one side of the car up? slide under the car to replace shocks? rinse/repeat on other side?

That easy?

going to google for a how-to video...

 

[biggestmuff]

Originally posted by: JEDI

Originally posted by: JulesMaximus

Originally posted by: JEDI

Originally posted by: Marlin1975
OP What is the year, FULL make/model (like hatch/trunk) and how many miles.


Shocks can go bad as little as 30k or less or last 100k. So there is no set magic number but if you have over 60k and the can has a lot of uncontrolled bounce from the rear then it may be time. It could also be a shop trying to make some money off you as shocks are very easy and require much less labor then struts. i.e. easy money for them.

2005 Mazda3i automatic, 82k miles. it has a trunk.

hm.. i also have lots of stuff (~200pounds) in the trunk, most of witch i should remove. how much heavy weight continuously in the trunk would be needed to damage the shocks?

the repair shop said $300 to replace rear shocks. 🙁

You can probably buy the shocks yourself for under $100 for a pair. Rear shocks aren't expensive and they are easy to replace. Usually it's just 2 bolts per side. Just make sure you don't overtighten the bolts.

hm.. use a jack to lift one side of the car up? slide under the car to replace shocks? rinse/repeat on other side?

That easy?

going to google for a how-to video...

If the Mazda crowd is anything like the VW/Audi folks (vwvortex.com), then you should be able to find some good DIY photos or videos on a Mazda specific forum.

 

[Knavish]

Your shocks might be bad, but I wonder if this is a popular scam item. I recently had my car in Firestone for an alignment & they wanted to replace all four struts -- I think they wanted close to $1000. (The self-leveling rear struts are somewhat expensive, but that price is still *way* too high.) I told them to forget it. They claimed they saw oil leaking, but when I rotated my tires a week or so later all the struts were dry.

 

[brblx]

Originally posted by: biggestmuff
If the Mazda crowd is anything like the VW/Audi folks (vwvortex.com), then run, run far away from the cesspool of stupidity before you fall in.

fixed.

 

[kornphlake]

Originally posted by: JEDI
anyway, they said my rear shocks had no resistance when the mechanic pressed on the rear tires when the car was on the lift.

That mechanic must be a hulk to be able to compress the rear suspension by hand and feel the lack of damping from the struts. I'd recommend never going back to that shop, they're trying to con you. Rather you need new struts or not is purely coincidental, there is no way you could tell if the struts need replacing with the vehicle on a lift unless they could see oil seeping out of the struts, if that were the case they should have said they saw oil seeping out of the struts.

 

[angry hampster]

Originally posted by: brblx

Originally posted by: biggestmuff
If the Mazda crowd is anything like the VW/Audi folks (vwvortex.com), then run, run far away from the cesspool of stupidity before you fall in.

fixed.

I bought a GTI last month, and have spent a good bit of time on Vortex. 99% of the people on there are complete idiots with no sense of class or style and way too much cash. However, the FAQ and DIY sections have loads of great info.

 

[JEDI]

Originally posted by: kornphlake

Originally posted by: JEDI
anyway, they said my rear shocks had no resistance when the mechanic pressed on the rear tires when the car was on the lift.

That mechanic must be a hulk to be able to compress the rear suspension by hand and feel the lack of damping from the struts. I'd recommend never going back to that shop, they're trying to con you. Rather you need new struts or not is purely coincidental, there is no way you could tell if the struts need replacing with the vehicle on a lift unless they could see oil seeping out of the struts, if that were the case they should have said they saw oil seeping out of the struts.

same thing w/shocks?

 

[kornphlake]

Regardless of the type of suspension you've got to compress the springs to feel the damping of the strut/shock, which would mean the mechanic had to apply a significant amount of force to the wheel when the suspension was fully extended to compress the spring with enough velocity to feel the damping or lack thereof. Assuming the weight of your vehicle is 3000 lbs the rate of the springs would be somewhere in the neighborhood of 700 lbs per inch of compression, that means that the grease monkey would have to be able to push the unweighted wheel upward with 700 lbs of force to move the wheel ~1 inch, I doubt your mechanic could do that and still have enough feeling sensation to be able to determine the condition of your struts. With the vehicle on the ground it's not too difficult to throw your weight on the car and get the suspension moving, like in the youtube video. For what it's worth, I've got over 180k on what I believe are factory original struts, they're worn, but I don't drive a race car and I don't expect my 14 year old car with 180K miles to perform like one. Worn struts/shocks are not something that have to be replaced immediately unless you feel like it's affecting the performance of your car. Wait until $300 doesn't sound like too much money and have the repair done then. The quoted price actually sounds pretty reasonable, but I'm suspicious of the diagnosis based on the method they claim was used to test the shocks.

 

[biggestmuff]

Originally posted by: angry hampster

Originally posted by: brblx

Originally posted by: biggestmuff
If the Mazda crowd is anything like the VW/Audi folks (vwvortex.com), then run, run far away from the cesspool of stupidity before you fall in.

fixed.

I bought a GTI last month, and have spent a good bit of time on Vortex. 99% of the people on there are complete idiots with no sense of class or style and way too much cash. However, the FAQ and DIY sections have loads of great info.

Which is what I originally wrote before some schmuck change it.