Evaluating Shock Condition

Superman · 10-26-2007, 07:23 AM

My city installed a speed bump wtihout mypermission or knowledge, and I hit that thing at perhaps 30 mph one night. Both wheels on the driver's side took a fairly sharp compression. It's one of those fat speed bumps, but high. A blob of asphalt a few inches high and a couple of feet wide. Anyway, my shocks are fairly new. Bilstein regulars. I wonder if they were damaged. What does it take to "pop" a shock, and how can I assess their condition now. I've bounced the bumpers, and they seem the same as the passenger side, but I still worry they were damaged.

Porsche-O-Phile · Porsche-O-Phile's Garage

You of all people should know better than to question the motives or actions of government. Big Brother knows what's best for you. Move along. . .

Sorry, couldn't resist.

tonythetarga · 10-26-2007, 07:47 AM

Quote:

Originally Posted by Superman

I've bounced the bumpers, and they seem the same as the passenger side, but I still worry they were damaged.

This does not give an assessment of the shocks. Remember you have torsion bars that are the springs, so when you bounce the car you are twisting the torsion bar. The shocks dampen the compression and rebound of the torsion bar.
The shocks are gas so you won't see anything leaking from them. Hopefully someone else will say a positive way to check the shocks without having to remove and test them.

livi · 10-26-2007, 07:50 AM

Happens a lot here in Sweden too. I am never consulted. Very annoying.

On the subject, I think your suspension survived if you don´t find the ride different than before. It was designed for negotiating rocks, bumps and the occasional German freeloader.

Superman · 10-26-2007, 07:59 AM

Quote:

Originally Posted by Porsche-O-Phile

You of all people should know better than to question the motives or actions of government. Big Brother knows what's best for you. Move along. . .

Sorry, couldn't resist.

Fair 'nuff. Big Brother also failed to consult with me on the traffic light camera thing.

Steve@Rennsport · 10:38 AM

Not to worry unless your car is lowered a bunch and they really bottomed out.

When that happens, the piston can strike the floating divider and the oil mixes with the nitrogen. If that occurs, the shock is dead.

This is one reason why they have those rubber bumpers inside there,..

dd74 · 10-26-2007, 10:06 AM

I've done the same thing here in L.A., but not at 30 mph, but more 50 mph. This usually happens where roads lower or grow apart with the ground's movement, or there's some sort of construction work on the street. Anyway, I have Bilstein Sports, and after countlessly driving over these "bumps" and/or "separations," I haven't noticed a single difference in my shocks - even after I've almost bottomed out. Personally, I'd worry more about my alignment, but that doesn't seem to be effected either.

Formerly Steve Wilkinson · 10-26-2007, 10:06 AM

Since Bilsteins are gas shocks, they either work or they don't. They don't fail slowly like conventional hydraulic shocks.

Superman · 10-29-2007, 07:23 AM

Thanks guys.

Hey, as long as we're at it, let's educate me on "gas" shocks. Some of you guys seem to think that "gas" shocks means they are not hydraulic. I doubt that. My belief is that "gas" shocks are hydraulic like any other shock, except that the air chamber is filled with a special gas rather than atmospheric air, so that the hydraulic oil is less likely to foam.

Do "gas" shocks squeeze a liquid through an orifice just like "regular" shocks do?

masraum · 10-29-2007, 07:56 AM

Super, you are correct, gas shocks have a gas charge as well as having oil in them. Even if you loose the gas charge the shocks can still work (they won't work as well).

I'd say that unless you notice different performance or you see fluid leaking out, you're probably fine.

masraum · 10-29-2007, 07:58 AM

Quote:

Originally Posted by Formerly Steve Wilkinson

Since Bilsteins are gas shocks, they either work or they don't. They don't fail slowly like conventional hydraulic shocks.

I'm not sure I agree. If they loose their gas charge, they still have the fluid that damps the movement.

burgermeister · burgermeister's Garage

Shocks stop working when they loose the oil (obvious), when they blow internal seals or other parts (obvious - no more damping), or when the internal valves slowly wear (eventually becomes more and more obvious).
The bump stops prevent overtravel of the suspension - unless they're gone, the worst thing that happened - given your car is driveable and the alignment isn't shot - is that you deformed the sheetmetal where the top of your strut mounts by some small, possibly unmeasurable, amount.

RWebb · RWebb's Garage

city does not need your permission or knowledge to installed a speed bump

- what you CAN do, is get a bunch of people to contact their city council and ask them to pass an ordinance that requires the city to post a sign saying new speed bumps installed, etc.