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Hi folks,

I've recently had PSS9's fitted, and want to check with those of you that have them fitted also, whether the smaller helper spring is installed above or below the main spring, (i.e at the top or base of the shock) and whether that is the same for the front and rear shocks. I've seen photos of them in both configs, and I'm not satisfied with the behavior of the rear suspension on mine - I thought it seemed to hit the bump stops, but now I'm not sure it has been and wondered if my issue could be as a result of the main and helper springs being fitted in the wrong order.

To explain, the rear just feels like it wants to launch the car back up after a larger bump in the road, such as when going over a train line crossing. It's almost like the car is going to flip forward and stand on its nose! Unless I've just had a bad week of driving on poor roads, I don't think that these coil overs should behave as mine are.

Has anyone else had this problem? Bilstein tell me that it shouldn't hit the bump stops on anything other than an extremely large bump, if set to a height within their recommended height range, which mine are.

The adjustment on the shocks is set to "7" front and rear. The fronts feel great, but the rears....

Thanks in advance

I doubt that it matters, they will work exactly the same on top or below.

FWIW, Heasmans installed mine with the helper below when they rebuilt them.

Are they new? Do they have the stock Bilstein springs? That behaviour suggests that there is something wrong, from your description it sounds like a dud/wornout shock. Try running them fully stiff, then fully soft, over exactly the same road (same speed etc).

Below on mine Gerard. Helper spring is fully compressed under load too, unless your car is really low - have checked this with the experts and they assure me this is the way they are meant to be. Rears are easy to remove - pull em off and check I suggest.

Thanks for the responses GC and John. These are brand spanking new, all Bilstein parts.

My helper spring on the rear is above, and I'm fairly sure below on the front, which is why I wondered if there is a difference... Sounds like that might be part of it, although as GC suggested, I too didn't think it would make any difference. I didn't install them myself, and they had to come apart to fit the top hats, so it looks like the change might need to be made.

John the car looks to be about the same height as yours. It's a little (maybe a few mm) higher than it was with the Tein's on, and they were set to give 100mm ground clearance.

Sorry GM, had you mistaken above for GC

I knew i had a pic somewhere. Mine are higher now than this pic, so helper is fully compressed.

Orientation of helper and main spring wont make a difference to the functionality, but officially it should be at the bottom.

What setting do you have the shocks set on?

Where did you purchase the shocks from?

Well, an update of sorts: I have contacted Bilstein in the US (bought through them) and the tech guy there tells me that it doesn't particularly matter if the helper spring is on the top or bottom, and that "out of the box" they're on the top... He has asked me to check the numbering marked on the springs. I have played with the rebound adjustment in the last few days and they are starting to feel better. Shocks are now set at "7". I'm becoming happier with them, and I think perhaps they have just taken some time to settle in.

I know it's an old thread, but stumbled across it as I'm about to install my PSS9 kit.

Anyway, the dust boot looks mangled, like it's getting caught in the springs!
I'm just guessing, but this might be causing the problem described.

It's all good, the PSS9's have settled in and I couldn't be happier with them. No problems with the dust boots on mine, they're all ok, or at least were the last time I looked, so no they weren't the cause of the problem. Cheers