Testing MacPherson Struts?

[bwilson4web]

Is there any 'metric' based test protocol? Trying to bounce the front end or answering "does your steering wander" is a bit vague.

Thanks,
Bob Wilson

[Pinto Girl]

<div class='quotetop'>QUOTE(bwilson4web @ Oct 12 2006, 04:24 PM) [snapback]331963[/snapback]</div>

Is there any 'metric' based test protocol? Trying to bounce the front end or answering "does your steering wander" is a bit vague.

Thanks,
Bob Wilson
[/b]

That's a good question; I'm not aware of one, but certainly doesn't mean one doesn't exist.

There are two tests of which I'm aware, and both are visual.

1. If they're leaking, then you've got a problem. Sometimes you can look closely, and you may see evidence of wear on the body of the strut (as the mileage gets higher), and possibly some dampness or even actual drainage. Either of the latter are a warning sign.
2. You could either hang your head out of the window or ask a friend to drive next to your car while you're on the expressway. A bad shock or strut will allow the wheel to bounce up and down rather a lot, and it will happen pretty frequently, too (not just when there are bumps in the road).

I had a problem with a bad rear strut on my Miata, and the way I finally convinced the service rep was to have someone drive next to me and check it out...the wheel was bouncing so much that they came around right away and replaced both struts under warranty.

I'm curious; why do you want to test them in the first place? Do you suspect that there is a problem?

[bwilson4web]

<div class='quotetop'>QUOTE(Pinto Girl @ Oct 12 2006, 06:36 PM) [snapback]331999[/snapback]</div>

That's a good question; I'm not aware of one, but certainly doesn't mean one doesn't exist.

There are two tests of which I'm aware, and both are visual.
. . .
I'm curious; why do you want to test them in the first place? Do you suspect that there is a problem?
[/b]

I'm not sure but having recently bought new tires, this would be a good time IF there is a good test or metric:

- car has 71,000 miles and came from Texas with 49,300
- first transaxle oil change revealed substantial dirt/grit in transaxle oil
- steering is 'dead' neutral, no wandering but no tracking either
- another user reported failing a "NJ vibration test" but I can't find a description
- same and other users report improved 'regeneration' after MacPhearson replacement
- availability of after-market, non-Toyota MacPhearson struts

I've only got about 2,000 miles on these new tires and now would be a good time to improve the front-end suspension and ride. But I prefer to understand the metrics, the characteristics, to determine if the current ones are nearing End Of Life and what to look for in an upscale pair.

Bob Wilson

[Pinto Girl]

<div class='quotetop'>QUOTE(bwilson4web @ Oct 12 2006, 08:59 PM) [snapback]332078[/snapback]</div>

I'm not sure but having recently bought new tires, this would be a good time IF there is a good test or metric:

- car has 71,000 miles and came from Texas with 49,300
- first transaxle oil change revealed substantial dirt/grit in transaxle oil
- steering is 'dead' neutral, no wandering but no tracking either
- another user reported failing a "NJ vibration test" but I can't find a description
- same and other users report improved 'regeneration' after MacPhearson replacement
- availability of after-market, non-Toyota MacPhearson struts

I've only got about 2,000 miles on these new tires and now would be a good time to improve the front-end suspension and ride. But I prefer to understand the metrics, the characteristics, to determine if the current ones are nearing End Of Life and what to look for in an upscale pair.

Bob Wilson
[/b]

You know, years ago I'd guess that it's 'time' but now...I wonder. My '96 RAV4 has 110k miles on it, still with the original shocks and struts, and drives okay.

I did a quick search on the vibration test and NJ, but didn't come up with much; from what I can tell from the state of New Jersey website there's an emissions test and they check the function of the lights, etc., but nothting mentioned about suspension.

Don't know why regen would be any better with new struts, tho.'

I'd say that if it drives okay and the tread of your tires isn't wearing in a cup pattern, then there's still left in 'em. Besides, unless they could be tested while still on the car, you'd be spending so much in labor (unless you did it yourself) that, even if the current ones tested okay after they were removed, you might as well replace them. The car is is already apart, after all...

From what little I know about aftermarket shocks and struts, the 'better' ones have improved valving and are designed to resist 'foaming,' i.e., when the temperature inside the body rises enough to cause the oil to change consistency. This happens after hard use, usually, and I can't imagine this really being an issue with our fair Prii.

I recall Koni being a good brand, and they're adjustable, but the ones I had years ago had to be removed to make the adjustment, which didn't make it any easier.

Ended up being like the tone controls on my stereo; played them for a while and then left everything at 'zero' and for the most part forgot about that feature. I never really knew if making them stiffer or softer was better or worse, and in what combination.

[Beryl Octet]

<div class='quotetop'>QUOTE(bwilson4web @ Oct 12 2006, 05:24 PM) [snapback]331963[/snapback]</div>

Is there any 'metric' based test protocol? Trying to bounce the front end or answering "does your steering wander" is a bit vague.

Thanks,
Bob Wilson
[/b]

It's a bit vague, but so is trying to describe to someone how the car feels with a low tire. I'd think at 71K they are probably still good. Check for visible leaks as someone suggests. The bounce test is probably the best way to tell, the other is to drive them on a crappy stretch of road and note how much bounciness you get. I drive other a bridge with bad expansion joints, and it is perfect for this kind of test. What kind of problems are you having with the bounce test? Some cars have no bounce, like my ex-Mustang with aftermarket springs, i.e. super stiff suspension, but the Prius seems bouncy enough; I bounce it every time I get gas to make sure the tank is somewhat full. Basically, get the car bouncing, then release on the downstroke. It should go up to the normal ride height and stop. If it goes up and back down, then you need struts.