Replacing Struts

[CL8]

I recently was told, after getting an oil change that my 1999 Dodge Caravan (130,000 miles) needs new struts at a cost of about $700, Last spring I was told the same thing about my grandmas 1991 Ford Escort with less than 70,000 miles on it, for just under $700.
I have never heard of anyone I know replacing the struts on their vehicle and I'm feeling like it's more of a money maker for the mechanics than is necessary. I'm not sure the cost will be worth it for how soon I might get another vehicle.(though I really like my Caravan!) I don't feel excessive bouncing of my Caravan when I drive, and it seems to run fine. Any input is appreciated.

CL8

[shorod]

That's the funny thing about struts and shocks - they wear gradually over time so you don't necessarily notice a change in the ride. Worn struts are more easily seen from someone outside your vehicle.

What shops often use as a determination for when struts need to be replaced is evidence that oil is leaking from them at the seal where the strut rod enters the body. If they are leaking (and the oil wasn't placed there by an unscrupulous technician) that is a sure sign that they are worn and should be replaced. If the struts/shocks are far gone, you may also see signs of cupping/scalloping of the tire tread.

Years ago when I was helping my dad around his shop we saw quite a few bad struts, I'm not sure if things have changed in recent years. We worked primarily on domestic branded vehicles and back then the most common make to have bad struts was GM, followed by Chryslers, then Fords. I'm not sure how many Fords we had in versus GM, but I would say that we had more of each of those than Chryslers come through the door. Our primary clue was signs of oil followed by tire wear. Noticing oil leaks though was difficult in the spring (rainy season) and winter (snow melt) but some had been leaking for so long grime was caked up on the strut body making those pretty obvious.

-Rod

[CL8]

Thanks again Rod, other things I've read about bad struts is if your vehicle bounces more than three times after going over a bump or pothole, it's time for new struts.
Today I drove my Caravan about 5 miles through a hilly, windy back road of Portland, with lots of speed bumps and I couldn't detect more than one smooth bounce going over the speed bumps. I'm not sure what scalloping of tire tread is but I will check it out.

CL8

[MagicRat]

Originally Posted by CL8

Thanks again Rod, other things I've read about bad struts is if your vehicle bounces more than three times after going over a bump or pothole, it's time for new struts.

Ideally the suspension should just rebound after a bump with no bouncing at all. 3 bounces is too many. IMO anything more than one bounce us excessive, since it makes handling less predictable and makes for a busy, bumpy, unpleasant ride.

[shorod]

Originally Posted by MagicRat

Ideally the suspension should just rebound after a bump with no bouncing at all. 3 bounces is too many. IMO anything more than one bounce us excessive, since it makes handling less predictable and makes for a busy, bumpy, unpleasant ride.

Agreed, plus it's somewhat difficult to feel/see the rebound versus subsequent bounce from inside the cabin, hence my comment about being more easily seen from someone outside the vehicle.

As for scalloping of tire tread, that can be easily felt by running your hand around a tire tread surface. If it slides pretty easily in a counter-clockwise direction but catches and you can feel high points when sliding your hand in a clockwise position, that indicates scalloping/cupping and suggests something isn't right. It could be struts/springs, it could be a balance issue, or it could be an alignment issue. In some cases, it could be a tire design issue (I don't think I ever saw a Goodyear Invicta tire that didn't have some amount of cupping).

-Rod

[CL8]

Originally Posted by MagicRat

Ideally the suspension should just rebound after a bump with no bouncing at all. 3 bounces is too many. IMO anything more than one bounce us excessive, since it makes handling less predictable and makes for a busy, bumpy, unpleasant ride.

I would say what I felt was more of a rebound than a "bounce" however, as Rod mentioned, I don't know what it looks like to someone watching from the side of the road.

From Shorod:
As for scalloping of tire tread, that can be easily felt by running your hand around a tire tread surface. If it slides pretty easily in a counter-clockwise direction but catches and you can feel high points when sliding your hand in a clockwise position, that indicates scalloping/cupping and suggests something isn't right. It could be struts/springs, it could be a balance issue, or it could be an alignment issue. In some cases, it could be a tire design issue (I don't think I ever saw a Goodyear Invicta tire that didn't have some amount of cupping).

I also checked over my front two tires today and they look very good, I didn't see any uneven tread that would look like scalloping you describe.
These are the 2007 tires I posted about not long ago, because they are coming upon four years old, but I only drive the van a couple times a week so they don't get much wear.

I might take my daughter with me on a street with speed bumps, have her drive over the speed bumps while I stand outside and see if I can detect excessive bouncing from outside the van. If I do that and can't see much bouncing, I will be convinced my van will be fine without replacing the struts at least for now. Does that sound reasonable?
Also at what speed should I (or my daughter) be driving to test the bouncing?

Thanks,
CL8

[shorod]

Originally Posted by CL8

I might take my daughter with me on a street with speed bumps, have her drive over the speed bumps while I stand outside and see if I can detect excessive bouncing from outside the van. If I do that and can't see much bouncing, I will be convinced my van will be fine without replacing the struts at least for now. Does that sound reasonable?
Also at what speed should I (or my daughter) be driving to test the bouncing?

Assuming these are typical speed bump that are short and abrupt, that sounds like a good plan. I don't think the longer speed ramps like you might find at an airport would be very effective. The normal speed bump speed should work fine. Is that around 5-10 mph?

-Rod

[slo99sierra]

You can also push ontop of/jounce each corner of the car to determine if the strut is bad or not. You can see the jounce/rebound easier.

Go to driver side or passenger side front, push down HARD on the fender/hood 2 or 3 times to get it jouncing and then let go and see how many times it jounces/rebounds. As stated - more than twice it's bad,=. - only once, it's good.

I would suspect the front first being that the struts carry a lot more weight than the rears.

[Scrapper]

Originally Posted by slo99sierra

You can also push ontop of/jounce each corner of the car to determine if the strut is bad or not. You can see the jounce/rebound easier.

Go to driver side or passenger side front, push down HARD on the fender/hood 2 or 3 times to get it jouncing and then let go and see how many times it jounces/rebounds. As stated - more than twice it's bad,=. - only once, it's good.

I would suspect the front first being that the struts carry a lot more weight than the rears.

he no's what he's talking about because he put down jounce allot of people call it bounce. can you see them leaking? also you will probably change upper strut bearing plates those were go to go only for about 30.000 mls on the bearing plate that came out when car was new. also there about the same set up on v/w's. just wanted you to know about upper bearing plates on struts.

[CL8]

Ok, I felt around what I could see of the struts inside of the front tires. All that got on my fingers was black dust, but NO grease or oil.
I couldn't see where the struts on the rear were to feel around them. (any help on where to see the rear struts on a Caravan?)

My daughter didn't have time to help me look for jounce going over speed bumps, so I did the push test as hard as I could, barely any movement or bounce,
however my arm strength isn't very strong, (I couldn't turn the cold water spout hard enough under my sink to stop a drip from my faucet) so I'm not sure what that was worth.
But no evidence of oil leaking from the struts, I'm more and more thinking these mechanics are just trying to make money from me. I still plan to do the speed bump test when I can.

Thanks for all the help

CL8

[shorod]

A 1999 Caravan I think still has the solid axle and probably still have shock absorbers rather than struts in the rear.

-Rod

[Scrapper]

if front struts arn't leaking i would not replace them you may have to replace upper bearing plates they are bad at that. and if not jouncing and front tires arn't cupping you can tell if there cupping by running your hands around tires. and the back ones are probably shocks you can tell by looking to see if the shocks arn't running threw the coil springs there just shocks.

good luck....

scrapper...

good luck...

scrapper...

[CL8]

Well today I got my daughter to drive with me to her high school parking lot, being almost empty. I had her drive the van about 150 feet back from the speed bump in the parking lot.
I told her to get the van up to about 20mph going over the bump while I stood out ahead to the side watching the front of the Caravan. I had her do this going both directions while I watched.
From my view, the van went over the speed bump both times about as smooth as Jimmie Johnson crossing the finish line at Nascar. I saw practically no bounce/jounce, not even a dive in front or back. This speed bump was probably meant for 10-15mph being in a parking lot, and she was going 20mph.

I have concluded my van is in fine shape without spending $700+ for new struts at this point.
If anyone thinks of anything I have neglected to look for in determining the need for new struts on my Caravan let me know.

*Although how would I check the upper bearing plate Scrapper mentioned?

Thanks CL8

[MagicRat]

Originally Posted by CL8

If anyone thinks of anything I have neglected to look for in determining the need for new struts on my Caravan let me know.

*Although how would I check the upper bearing plate Scrapper mentioned?

Two things: first of all, you should be commended for doing the research on the struts so thoroughly.

But there is one factor that has not been mentioned - and that is ride and handling "feel".

This is a bit difficult to convey in words, but generally, an experienced person can tell if struts and shocks are not well matched to their springs.... even if the car does not obviously seem to bounce too much.

Ideally, struts and shocks are matched to the weight and spring rates of the vehicle. A soft or slightly worn strut allows just a bit too much bounce and sway....... not enough to be obvious, but it just feels a bit wrong.

I experienced this with my '88 Pontiac. I changed the struts....... and the new ones were not quite right..... slightly too bouncy. It turns out the auto parts store gave me struts intended for the LE model. My car was the SE model, with slightly stiffer springs.

To me this was annoying, because the car was just a bit "wrong". The LE struts were not perfectly matched to the stiffer SE springs.

But my wife never noticed. Although I tried, I could not get her to understand exactly what was wrong.

Eventually I got the right struts, and all was well again. But my wife still did not feel any difference, simply because the differences are so subtle. The car felt just the same to her.

I should add the reverse also happens..... it is possible to get struts that have too much damping. A friend had an Oldsmobile Ciera with softer, base-model suspension. He got struts intended for the stiffer, sportier Ciera. The struts were too "stiff" and did not allow the springs to rebound fast enough. When going over a bumpy section of road, the springs would quickly sink and the suspension would hit the bump-stops.

So..... unless you are as picky as I seem to be, your existing struts are probably fine.

As for the bearing plates..... when they go, you get poor tracking. Try this...... Go to an empty parking lot. At lower speed, turn the steering wheel all the way to the left, and drive around in a circle once. Do this at a decent pace, so you are generating some cornering forces. Then release the wheel and let it straighten up. Does the van want to go in a straight line, or does it pull to one side?

Repeat this while going around a right hand turn. If your bearing plates are good, the van will always straighten up and drive straight. If the plates are bad, the van will often pull to the left sometimes, then to the right at other times, depending on the direction of the last corner you took.

[CL8]

Thanks MR! (and everyone else)

I will try the donut test this week in a parking lot to check the bearing plates.