re <VV> Convertible damper canisters

[James Davis]

Think of the late model convertible body dampers as shock absorbers 
for the body.  The body has little torsional stiffness and has a 
resonance frequency of around 10/11 hz.  Just like a car worn out 
shocks, if you never hit a bump, you never need shocks.  The shocks 
are there to dampen out the spring oscillations from the bumps.  The 
canisters have a 14 lb lead piston supported by a spring that 
maintains the piston approximately at the center of the canister.  If 
the body moves suddenly in the vertical plane, inertia tries to keep 
the piston in the same location, so the pistons moves rapidly up or 
down in the canister.  The fluid in the canister resist this motion 
and turns the excess energy into heat.  The canisters get quite hot 
on a bumpy gravel road with spirited driving.  The should be completely filled.
Jim Davis



At 09:52 AM 2/5/2007, Ron Choy wrote:
>When I got my 66 vert over 15 years ago, I had the dampers out 
>for  resinonance
>cleaning. I found all four dry. I drove the car without them, with
>seemingly no difference.
>    I've no idea how much ATF should be put in them. I realized
>several months ago that I filled them completely, and I think that
>would restrict the slug's movement. I believe there should be air at
>the top so there would be free movement.
>   As I say, in or out, I've never noticed a difference. I have a
>front pair in my 65 sedan and still don't notice a difference.
>   They must be important or The General wouldn't have spent money
>installing them. -ron 65,66