How do I know if I need to change my shocks?

[TobyQuest]

Hi all,

I have noticed while driving over the last 2000 miles or so that my MH really judders and thuds when I go over potholes, some speed bumps etc. This has got worse since I first owned it.
I have leaf springs on the back and torsion bars on the front suspension.
The previous owner put Rancho shock absorbers on it which are more performance type shocks and it looks like they all have a small valve on them.
Is this so that hydraulic fluid can be topped up? I dont understand what this valve is for.
Does it sound like I need to replace the shocks or is it cheap and simple to replace the hydraulic fluid and try that instead?

 

[CazPaul]

When they smell.

 

[CazPaul]

Sorry bud, had a couple of beers, just read it again, I thought you said socks.

 

[Gerby]

I thought you meant pants (I have had even more beers)

 

[dunnah01]

What manufacturer is it to have front torsion bars?

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[Odd-no-more]

Very difficult to test shocks when loaded. Try rocking the van if it doesn't stop rocking they are shot.

 

[TobyQuest]

Its a Nissan Cabstar.
I do feel that if im inside and throw my weight to one side it will go that way, then the other way, then back again and perhaps back the other way one more time.
Does that sound like theyre shot? And if so it means what, only that the hydraulic oil inside the shock is gone presumably?

 

[Driventemple]

Although often referred to as shocks or shock absorbers, what you are asking about should more accurately described as dampers. The spring actually absorbs the road shock and the dampers reduce any subsequent bouncing action that would take palce if any spring is loaded then released. You say the previous owner fitted performance dampers. You mean they are adjustable. The valve allows you to stiffen up the damper or soften it. As a motorcaravan is a high sided vehicle the owner may have wanted to reduce body sway? Are the dampers leaking? You say that it judders and thuds over potholes. Are they adjusted too stiffly? Check the rubber bushes on the suspension as if they are worn it will creat a knocking sound.