I started my Konis set at the firmest. They now have 115K miles and it feels like they've lost a little control on the rebound. Does that amount of mileage indicate replacement? Removing and feeling by hand is the only way I know to test.
Not really. That is what is says on their adds, but when I bought them, I bought them direct from Koni. They shipped them loose in a box (wrong box) with no receipt. Now that they are worn out, I emailed stating that they were worn out and explaining that I did not get a receipt and how they were shipped to me. They emailed me back telling me I needed the receipt (that I never got) to prove I was the original purchaser. So that puts me in a stalemate, meaning they win and I loose. Except I'm not as much of a Koni fan as I used to be. Its too bad, because the shocks worked great for the first 30K miles or so. But now they have very little rebound damping.