Average lifespan of KYB AGX struts?
 

For those of you folks having experience with KYB AGX shocks/struts: What would say is the average lifespan of KYB AGX shocks/struts?

I installed four KYB AGX shocks/struts on my S5 coupe in Jan 2003, which was over 16 years ago. I've got over 143k miles on these shocks/struts.

As far as I can tell, they still seem to be okay. I recently cranked the adjustment up a notch to 3 (rear) and 3 (front), and I'm getting a firm but controllable ride. BTW, I'm running them with Eibach Pro-Kit progressive rate springs. They have no apparent leaks. The front brackets, that attach the strut to the spindle, have some rust where they're welded to the strut. There seems to be some minor bulging of the bracket at that point too. I'm certain the rubber bushings are shot after 16 years of wear and tear. I know that KYB offers a lifetime warranty, but I no longer have the receipt. I don't think I'd even approach KYB regarding the warranty after 16 years and 143k miles.

KYB recommends replacing shocks/struts after 50k miles. Another suspension website that I viewed said to replace shocks/struts by 75k miles or sooner. I checked out KYB's reviews and some people have claimed the their AGX's "blew out" only after 30k or 40k miles. On the Miata forum, people claim to have gotten only 30k-40k miles out of them. Still, other have had no problems.

KYB is offering rebates until the end of September. I hate laying out the cash for a new set, but also don't want to pass up the rebate while it's available.

So again, for those of you folks running KYB AGX shocks/struts:
1. What kind of mileage did you get out of your AGX's?
2. If one or more of them failed, how did it fail?

Thanks for your feedback and have a safe Labor Day weekend!

To make you feel better, I still have the OEM suspension on the '89TII, 215,000 miles.
Unless you see a leak or notice any unusual rebound, they're good to go.

Hot Dog - I've got an almost identical suspension setup with the KYB AGX struts on my '89T2. Only difference is I'm running the Racing Beat springs instead of the Eibach's. I installed mine back in 2004, put about 40K miles on the car since then. They seem to work as good as new, and the adjustment ranges still work as they should. I typically keep mine in the middle setting of the range, 2 front, 4 rear.

Unless the struts are leaking, the car bounces over bumps or the car fails the "corner bounce" test, I wouldn't replace them just based on mileage or years in service.

At this point I would replace them. 16 years and 143K they are likely close to fail. One of those things, better to replace before failure and creates worse problems. If you have the money and the time it's a easy decision.

Being a technician, rule of thumb is 100,000 miles unless you notice tire wear or leaks. AGX are great, I've had a few sets myself. Unless you notice tire wear or ride quality declining I would not worry. On the other hand... a new set of AGX is only $400

I haven't noticed any abnormal tire wear or leaking dampers. A new set of 4 AGX's at Rock Auto is $336 not including KYB's $50 rebate.