Ashyukun (Robert)
Ashyukun (Robert) GRM+ Memberand PowerDork
6/25/22 12:55 p.m.

So, could use some input to help determine if I'm just misunderstanding something about shocks...

Every shock (and strut) I've encountered in the past has been pressurized such that when it was shipped it was secured with a strap to keep it compressed, and when that strap was removed the shock would extend out to its full length. 

But the pair of shocks I just got from RA for the back of the QX4 don't do that... they had no straps on either of them, and they don't extend on their own at all. Within what looks to be the normal operating range of the shock on the SUV they do seem to have resistance to moving/be damping, but they're quite content to just sit at whatever length you compress or extend them to. 

Is this right/normal and I'm just used to dealing with a different kind of shock? Or are both of these shocks defective?

Thanks!

Slippery
Slippery GRM+ Memberand PowerDork
6/25/22 1:03 p.m.

Are those gas filled units? If gas filled, they should return on their own based on my experience. 

Ashyukun (Robert)
Ashyukun (Robert) GRM+ Memberand PowerDork
6/25/22 1:51 p.m.

It's hard to tell whether they are or not oddly... some pages say they are, but RA's own page doesn't mention it: 

https://www.rockauto.com/en/parts/fcs,342798,shock+absorber,7556

Interestingly, I'm pretty sure neither of the shocks I got have the red 'FCS' on the side of them, they're just all black. 

wae
wae PowerDork
6/25/22 1:58 p.m.

Every new shock that I've ever bought did exactly what you described:  Cut the wire and it starts extending.  Sometimes with frustrating results.  I've also heard, though, that when you're looking at used struts, pushing the rods down and seeing if they rebound on their own is not a good indicator if the strut is good or bad.  That said, every bad strut or shock I've ever dealt with would not rebound when compressed.

So, yeah, no real information or help there as it turns out, but, like you, I am suspicious. 

dps214
dps214 Dork
6/25/22 2:45 p.m.

There's a lot of things that could be happening. Dampers don't *need* to be gas charged, but it is beneficial mostly for heat tolerance. It's possible that they're low enough pressure that it doesn't really overcome the internal friction, or that the valving is locked down enough that the gas can't overcome that resistance, though that's not usually the case. Also if they've spent a lot of time on their sides or upside down that can make them do weird things, though it doesn't usually affect the gas reaction. And yes, hand compressing dampers is really only an indicator of if there's gas pressure which is an indicator but not a comprehensive test of the overall functionality. It's been a while but we had some FCS dampers at work a while ago for benchmarking and they're definitely cheap but I remember them being at least okay quality for what they were.

Tom1200
Tom1200 UltraDork
6/25/22 3:33 p.m.

The shocks you have are simply not gas pressurized.

The Koni shocks on my Datsun aren't gas pressurized and they work excellent on track. 

Loads of applications use non gas shocks. 

 

Ashyukun (Robert)
Ashyukun (Robert) GRM+ Memberand PowerDork
6/25/22 9:14 p.m.

In reply to Tom1200 :

Ok, that makes sense. 

I end ahead and installed them- it seems a bit softer than I was expecting I'll just have to see how it ends up riding (TWSS). 

Defined motorsports
Defined motorsports SuperDork
6/25/22 10:35 p.m.

And how many did you get? If all of them do the same thing it would be real hard to believe you got shipped 4 bad shocks. 

Ashyukun (Robert)
Ashyukun (Robert) GRM+ Memberand PowerDork
6/27/22 10:01 a.m.
Defined motorsports said:

And how many did you get? If all of them do the same thing it would be real hard to believe you got shipped 4 bad shocks. 

I got two, the front of the QX4 uses struts and not shocks, and both of the 2 I got were the same. Both were wrapped up and boxed the same, so I'm not inclined to think that they were returns or anything. As I said, once installed the rear end feels a bit softer than expected, but they do appear to be damping so I'll just have to wait until I take it out and drive around to see what I think.

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