How long should a strut last?
 

I've got 55k miles on a set of OEM struts, '01 S80, 2.9L. The mounts are rattling and need to be replaced, i'm trying to learn how to gauge if the struts should also get changed out. The ride is still relatively stable without too much sway. i can push down on the front bumper and it slowly rises back to the same height with no up/down bounce.

So, how many miles is reasonable to get on the struts, and is there another way to test for them being on the verge of dying?

Mine went out 152,000 miles on them. While replacing brakes, noticed oil on the struts. Dealer confirmed that a few days later.
One way to know if the struts are worn if the ride is harsh/hard.

My rear struts are still fine and my car has 164,000 miles. (1999 S80 T6)

Holy Smokes! 152k miles on the same set of struts? Wow, i need some of those. :)

The ride isn't harsh, just feeling a lot more of the bumps from the road.

Any others of you out there with thoughts on signs of struts going bad?

Information removed.

Thanks ES6T. That's what i'm leaning towards as well.

1986 & 1988 740T S/Wagons - 150+K - KYB GR2 Life-Time Replacements
 

I use KYB GR2 Front & Rear Struts. They're lifetime warranty replacements.
When I replace the struts, at that mileage, I rebuild the entire strut assembly;
HD Swedish/IPD springs, front mounting plates, rubber donuts, rubber mounts, boots, bearing sets, caps. For the FWD, I reuse the mounting plates. Aftermarkets, regardless of the Euro brand, are manufactured in CHINA, which from bad experiences, will never buy any of their products again-No Quality Control/Assurance. I also rebuild the Front End Steering/Suspension w. Meyle Anti-Sway Bar Links, Lower Ball Joints, Outer Tie Rods, Strut Rod Noeprene inner/outer bushings. I invested in a MAC Front Spring Compressor in 2004 & have rebuilt (6) Volvo suspensions. I allow (3) hours time per side. I can complete each in (2) hours, BUT something usually occurs. The old Strut Nut is usually frozen/rusted onto the cartridge shaft. In this event, I take out the entire FT Strut Assembly, mount on my work bench & placed, wrapped in old towel, in a mounted vice. Eventually, I'm able to free the net w. WD40 by soaking & allowing to set & break the bond. This spring compressor was a great investment. After rebuilding & upgrading/replacing the worn steering components, you'll want to realign the front end. The best price I've found is Firestone's Lifetime alignment warranty $175. Unlimited realignments; every 6 months is my standard. Plus, I buy my Michelin Tires at Costco for their semi-annual July & Dec $70 discount for (4) tires. I have the tires balanced & rotated for free, plus flat tire repairs. I've had Bilsteins, Boge-Mulhollands, Koni & KYB. I prefer the KYB. I drive my s/wagons over 300K miles, then give them to nieces/nephews. My favorite Volvo is the 940T 1993-95 RWD Turbo 2316cc/2.3L B230FT engine & AW71 tranmissions. I have 2 XC70 Volvo AWD swagons. These cars are link Abrams M1A2 Battle Tanks.
They're solid, more dependable than otherwise. They're 4500 lbs & forge through the Winter Snow like snowmobiles w. the AWD technology. Also, I get 28MPH Hwy & 18+MPH City. They're one of the most comfortable cars for highway/long distance driving. PC

Hey Phil, thanks for the comments. I've got Sachs on the front right now and have been pleased with the ride, not overtly impressed, but pleased enough to consider them again, but how would you compare the KYB ride to the Sachs?

KYB - Better Ride & Lasts 110-150Ks
 

KYB is a better strut, in my opinion. They're Japanese, originally. My last set was made in Japan. I check the box & request country of origin. They ride nice, last longer & are hassle-free Life Time warranties. Just save your receipts.
If I were choosing between Sachs & KYB, I'll choose KYB every time. PC