I recently purchased a set of new Bilstein shocks. They arrived in their old original Bilstein box. The shocks are new and in excellent condition. My only concern is that they're old stock. I don't know exactly how old, but they're embossed "Made In Western Germany."

So, I'd like to know if new shocks deteriorate over time. The ones that I have seem to have been in good dry storage since they were manufactured. They have absolutely no rust on them and the original box is very clean and dry without any moisture stains in it.

The shocks seem to operate as they should, but I just tested them by compressing and releasing them. I don't know if there's anything in particular other than a lack of resistance and the return from a compressed position that I should be looking and/or listening for.