[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [New Search]

Re: [T3] another question about shocks

On 28 Oct 2005 at 10:18, Russ Wolfe wrote:

> Gas filled shocks that I have bought were pressure filled with nitrogen.
> I just put a rear set on my mother's Chevy Lumina. They come from the
> factory with a metal clip to hold the rod compressed while in shipping.
> When this clip is removed, the rod extends under pressure. They are
> using the nitrogen gas inside as a dampener, as it is compressable.
> while oil isn't. This give s smoother ride in the car.

Not quite true. The damping material is still oil, they'er just using the 
compressed N2 to keep the oil under compression so it won't cavitate, and to 
keep the shock from sucking air in around the shaft seal.

There's a LOT of misunderstanding about this, but the best way to think of 
these would be to start describing them as gas over oil, rather than just 

There is no way that gas alone could give enough friction here to be useful.

BTW, I was surprised to find that the damping piston in these is sealed against 
the wall of the cylinder with a metal ring that is just a small piston ring. I 
was expecting a rubber O-ring, but that wouldn't last. The steel ring, running 
immersed in oil, lasts a long time.

Jim Adney
Madison, WI 53711-3054

List info at http://www.vwtype3.org/list | mailto:gregm@vwtype3.org

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [New Search]