KYB Struts: How long should they last?

[ibekir]

Hello all,

I installed new front and rear KYB struts 6 years ago. That was 54,000 miles ago. Im now at 207K. I started to notice some pretty decent body roll once Im above 65 MPH.

The struts are not leaking. I've done the bounce test and they seem to rebound well. But I'm only 155lbs. So there's that. The lower ball joints are pretty shot. Im having them replaced this week. I dont think that would be a cause, but it needs to be done.

I dont go 4x4. But I will hit the occasion fire road : ) Its a city vehicle so its no stranger to potholes.

Could the struts need to be replaced after 6 years and 54k? What else would turn my car into a waterbed when on the highway?

2000 V6 SR5 4WD

Thanks.

 

[Brian.]

I had TERRIBLE body roll, especially on the highway, right after installing brand new Bilsteins.. and it was 100% resolved after I replaced all the 20 year old, 200k mile bushings (front and rear, upper and lower control arms, steering rack, sway bars and panhard bar). Made more of a difference than the ~$1200 shocks for on-road ride.

I'd start there. You'll need an alignment after doing this, and there are a whole host of issues that might show up with the cam adjusters on the front lower control arms. Plenty of info here in the forums though.

 

[3bears]

well I got over 40k out of a set that I had also done new springs. They saw as much off road as pavement ( mild off road) then switched to a 3 inch lift, kept them around as they were still good. swapped them all over to a rig that was worn out and was selling, and they did better then the worn out system that were on that one. Did not claim/advertise or anything on the one being sold as to life/age of shocks etc.
Are you seeing any leaking ? I have been told that they will start leaking fluid when going bad...I have not experienced that. If you can prove they are bad, and if you are original buyer, they do have a lifetime warranty I believe....but I dont trust lifetime warranties.
I have used KYB's on volvos, other yotas ( corrollas and an old taco of one of my sons) and dd bmw and never had an issue.

But agree with what Brian said ( above) at the age of these rigs...so many rubber parts that can effect body roll etc are getting pretty warn out.

 

[Sarki]

Replacing the bushings front & rear as mentioned will make a significant difference if your still running the originals @200K+ miles.
I replaced all rubber bushings in the rear suspension at that mileage on my 02 and it resulted in much better handling and stability at highway speeds.
I have new Whiteline LCA bushings as well as cam adjusters & steering rack bushings on my workbench ready to go once I have the time to start that project.
I have 20K miles and 2 years on my KYB’s and have no issues with them.

 

[FD7683]

You can probably get away with new sway bar bushings and fresh end links (if they are shot). Check your front bar under the car for play/movement. I'm currently running Energy Suspension polyurethane sway bar bushings (black) and they are still doing great with no squeaks. Like everyone said - the majority of the movement is coming from the degraded control arm bushings.

 

[audiness]

in my experience aftermarket shocks last about 30-40k miles at most. OEM shocks seem to last way, way longer.

 

[Albyneau]

Hello all,

I installed new front and rear KYB struts 6 years ago. That was 54,000 miles ago. Im now at 207K. I started to notice some pretty decent body roll once Im above 65 MPH.

The struts are not leaking. I've done the bounce test and they seem to rebound well. But I'm only 155lbs. So there's that. The lower ball joints are pretty shot. Im having them replaced this week. I dont think that would be a cause, but it needs to be done.

I dont go 4x4. But I will hit the occasion fire road : ) Its a city vehicle so its no stranger to potholes.

Could the struts need to be replaced after 6 years and 54k? What else would turn my car into a waterbed when on the highway?

2000 V6 SR5 4WD

Thanks.

Compression and rebound is a function of springs, not shocks. Does it lean more in front or the rear? I've been using Monroe, KYB's, and Bilsteins on various vehicles for half a century (don't ask my opinion of Gabriels...) and never returned A SINGLE SHOCK.
Over 65mph? What kind of roll do you get at various speeds?
I could ramble on for hours on handling characteristics, but the bottom line is you've got sloppy sway bar connections~ and at 65mph some roll center issues that might ruin your day.... :lookout:

 

[Brian.]

Compression and rebound is a function of springs, not shocks.

As someone with a few certificates from various shock manufactures (Penske, Ohlins and Fox) that claim I'm authorized to repair their products as their representative, that's painful to read because it's so wrong. Compression is controlled by Both the physical spring characteristics (rated by how much weight it takes to move a specified distance, since most are US based with freedom units, that's be pounds per inch) AND the damping characteristics of the shock, which is a function of oil viscosity passing through either holes or bending shims. At the very end, there's also an "air spring" (nitrogen commonly) that offers a very short, highly progressive spring.

And rebound, rebound has Nothing to do with the spring beyond trying to slow down how fast it wants to extend. That is 100% the shock, using the same oil viscosity and whatever damping function (holes or shims.. and that fancy electrically variable viscosity fluid).

 

[19963.4lsr5]

As someone with a few certificates from various shock manufactures (Penske, Ohlins and Fox) that claim I'm authorized to repair their products as their representative, that's painful to read because it's so wrong. Compression is controlled by Both the physical spring characteristics (rated by how much weight it takes to move a specified distance, since most are US based with freedom units, that's be pounds per inch) AND the damping characteristics of the shock, which is a function of oil viscosity passing through either holes or bending shims. At the very end, there's also an "air spring" (nitrogen commonly) that offers a very short, highly progressive spring.

And rebound, rebound has Nothing to do with the spring beyond trying to slow down how fast it wants to extend. That is 100% the shock, using the same oil viscosity and whatever damping function (holes or shims.. and that fancy electrically variable viscosity fluid).

Thank you for that. You said it much better than I could have.


Sent from my iPhone using Tapatalk