Selftaught Panda Mechanic said:

From what I read, Bilstein B4 dampers are well suited for extra-urban use - they are more responsive in cornering, but at the same time they are quite rigid and thus offer a poor ride on potholes and bad quality tarmac. I also came across a few complaints on Polish and Italian forums regarding internal noises and premature wear of B4's, however that can happen pretty much with any brand. Bilstein B6 and B12 are efen stiffer are are more of a performance/ semi-sport dampers. Not recommended for a daily driver.

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There's two things going on in the suspension; damping and shock absorbing.

The shock absorbing is not done by the "shock absorber" (i.e. the damper). It's done by the spring. A soft spring allows better compliance than a hard spring, so if your car is "stiff" in the suspension, then it's the spring, NOT the damper that is causing that.

The damper's job is to control the spring movement. It has to control the speed at which the spring compresses and also the speed at which the spring extends. A good damper will allow the spring to compress as quickly as it wants over small distances but gradually increase its resistance to movement as the compression becomes greater. Then as the spring extends, it has to do the opposite. A damper is a highly engineered piece of kit.. so they're expensive.

The cheap option for a lot of car manufacturers is to use a hard spring and not very sophisticated dampers, or a thicker anti-roll bar.. so essentially passing the job of controlling the movement to the springs rather than the dampers. It works after a fashion.. but the "ideal" is to have a soft spring and a more sophisticated (i.e. expensive) damper.

Obviously, ride is not as great with a firm spring and there's more stress on the bushes since they're softer than the spring, so they yield first. It "works" in that it functions okay for the price of the kit.. but it's not how you would engineer it if your life depended on it.

Anyways.. more expensive dampers will help (they can give the springs a bit more control) but ultimately the suspension wants softer springs.

Harder bushes (like the PU type) will last better than rubber... but since the suspension relies on soft bushes as part of the "comfort" part, then it's going to be a harder ride.

Dampers shouldn't bend and/or then wear out if they've been specced properly. Most dampers operate at some kind of an angle.. although 45 degrees might be pushing it. There may be a technique for tightening the bolts (e.g. making sure the trailing arm is at the operating ride height) so that could be worth some further investigation.

But by the sounds of it, I'd say the dampers are pretty much borderline consumable item.. so better we start thinking of them as such. They're not too expensive at least...?


Ralf S.

I just put QH ones on the back of mine. Ride is definitely firmer than it was at the back vs the originals, they had 46k on them so I don't know how much that factors in to the difference. Also while it seems to be settling, I'd swear the back ended up 1/4" higher than before. I am tempted to put the old ones back on but they were creaking and while the rubber at the top hadn't disintegrated it was showing signs of drying up. The Fiat ones are odd - there are holes in the rubber mount on that end, seemingly on purpose. Is it actually the case that they're supposed to be torqued up with the car back on its wheels?

I also have QH shocks to put on the front, some Kilen springs and Bilstein mounts. The front is definitely slightly too low and bounces a bit on dips. Since it was also making a clunk I thought I'd replace the whole lot. Question though - what are those metal parts that go on the top of the spring called and where can I buy some? It would be good to assemble the complete shock unit in the warm and have it ready to 'drop in' but those are the only parts I'm not replacing unless I can identify and buy some.