Change all bushings - worth it ? any experience ?

[malnitz]

Hi

I have a volvo XC90 T6 from 2004, which is approaching 20 years and a great ride.

I have this idea of changing all the bushings to make the steering/driving experience close to what it was originally

I have seen that FCP EURO has a complete suspension kit, which I was thinking of buying ....

https://www.fcpeuro.com/products/volvo- ... escription

... or a similar kit from another supplier

Does anyone have any experience - is it worth it or just a wast of time?

Thanks in advance, Søren

[ggleavitt]

That's exactly what you ought to do, replace most if not all of the front-end suspension wear and tear parts plus the rear trailing arm bushing. Can even consider doing new wheel hubs and bearings.

I'm skeptical of the Delphi LCA in the parts list and I much prefer Volvo parts for performance and longevity but as someone who has owned this vehicle new, you'll see an immediate improvement depending on what work has or has not already been done to date if you replace much of what's on that list. You're the original owner? This vehicle have any transmission work done on it?

Another thing to add the Sachs 314-125 struts noted in the list are pretty generic. Someone might offer an alternative strut that may be worth considering.

Tons of threads in this forum, on this site, and on other Volvo centric sites regarding front suspension work and the XC90.


Edit- You'll need new LCA hardware if you're going to do this right- 2 each LCA pn 987456, 1 each LCA pn 999403 and pn 985660.

[dikidera]

It's great, but only and only IF you don't buy HD bushing or anything with the name polyurethane in it.

[chitownV]

Yes, refresh your entire front suspension and some selected rear suspension parts. It is very specific which brands for each part will last and which ones will prematurely wear out. Please see this thread as a lot of time has been spent putting it together from the real-world experiences of XC90 owners:

https://www.swedespeed.com/threads/chit ... ts.590829/

[mallnitz]

Thank you all so much for your comments. This was exactly what I was looking for.

However the question about the transmission from GGLEAVITT, made me look into possible transmission issues. Not pleasant to read. The transmission on my T6 is the original and has to date done 220.000 km without any issues. But from what I read I should just be grateful and expect it to die from one day to the other.

As far as I can see there is no gearbox fix. Some are on their 4th gearbox, so investing time and money on suspension upgrades seem pointless. Bummer.

Unless of course I habe misunderstood something - if so, please help me.

Wishing you all a great day and thanks once again

[dikidera]

Yes, refresh your entire front suspension and some selected rear suspension parts. It is very specific which brands for each part will last and which ones will prematurely wear out. Please see this thread as a lot of time has been spent putting it together from the real-world experiences of XC90 owners:

https://www.swedespeed.com/threads/chit ... ts.590829/

Of course you are also pushing for poly mounts, which means stiffer ride. Stiffer ride, more vibrations = more fatigue and more awful driving experience.
At 235hp for the XC90 which is a heavy car, there's no sportiness to be had, to have what I'd call sport, that needs to be 400 or more hp. Without that kind of HP, I'd go for the smoothest ride quality possible. And only original Volvo will provide that/

As for the 4 speed gearbox...it's definitely problematic and I almost have not heard of someone not having issues.

[chitownV]

Yes, refresh your entire front suspension and some selected rear suspension parts. It is very specific which brands for each part will last and which ones will prematurely wear out. Please see this thread as a lot of time has been spent putting it together from the real-world experiences of XC90 owners:

https://www.swedespeed.com/threads/chit ... ts.590829/

Of course you are also pushing for poly mounts, which means stiffer ride. Stiffer ride, more vibrations = more fatigue and more awful driving experience.
At 235hp for the XC90 which is a heavy car, there's no sportiness to be had, to have what I'd call sport, that needs to be 400 or more hp. Without that kind of HP, I'd go for the smoothest ride quality possible. And only original Volvo will provide that/

As for the 4 speed gearbox...it's definitely problematic and I almost have not heard of someone not having issues.

You are actually very wrong on this. Dozens of XC90 owners have installed polyurethane without harshness. The durometer is softer for the street and the biggest improvement is removing the flex cutouts. The polyurethane also pivots the control arm while a rubber bushing has to twist. The rubber bushing will also transfer energy to the subframe while the poly will transfer energy up to the strut where it should, because the poly bushing pivots.

Research again for specific XC90 and real-world results because it will show the old thinking of poly and race durometer is old thinking. The XC90 is really top heavy and it could benefit from safer handling, less wandering, and less dynamic toe change that happens with rubber bushings. YouTube videos on what happens to XC90 rubber bushings. Do your real-world research rather than outdated thinking.

[dikidera]

My statements were based off the knowledge of what polyurethane is and what the rubber is in the bushings. Polyurethane from my understanding should have higher duro(shore number) than rubber in all circumstances, if this is not the case...then my bad. All the videos I've seen of poly mounts or bushings were always accompanied by increased vibrations.

Please clarify if the durometer is softer than original or not. Also, I do not own an XC90 or any XC vehicle, just a regular S60 and I feel a lot of vibrations currently, the thought of feeling more just puts me off any replacement part that does not improve this.

I recently had a discussion on this topic with mechanical engineers and they said things that conflict with the intuitive thought that rubber dampens vibrations. I asked them if I added more ways for the vibration to be absorbed, would that lower the vibration and they said no, I will just add more path for vibrations to be transferred. But this was for rubber, not polyurethane.

So if you tell me that polyurethane is more durable but ALSO dampens more vibrations leading to more softer ride, I would be very surprised indeed. More so because leading car brands that produce high horsepower models use rubber for their engine mounts(although some are active)

https://volvoforums.com/forum/engine-in ... unt-76943/
https://www.swedespeed.com/threads/poly ... ns.221701/
https://volvoforums.com/forum/volvo-850 ... ion-53725/

[chitownV]

My statements were based off the knowledge of what polyurethane is and what the rubber is in the bushings. Polyurethane from my understanding should have higher duro(shore number) than rubber in all circumstances, if this is not the case...then my bad. All the videos I've seen of poly mounts or bushings were always accompanied by increased vibrations.

Please clarify if the durometer is softer than original or not. Also, I do not own an XC90 or any XC vehicle, just a regular S60 and I feel a lot of vibrations currently, the thought of feeling more just puts me off any replacement part that does not improve this.

I recently had a discussion on this topic with mechanical engineers and they said things that conflict with the intuitive thought that rubber dampens vibrations.
So if you tell me that polyurethane is more durable but ALSO dampens more vibrations, I would be very surprised indeed.

Sounds good. Yeah, that’s always the first thought about harshness, but that’s the old wives tale. The durometer seems like it’s rubber, but it isn’t. The XC90 forward bushing is huge, my estimate is twice the size of an S60. So having cutouts in the bushing brings a lot of flex. To compare with other vehicle manufacturers, they opt to go fluid (hydraulic) filled for vibrations and don’t have the same flex issues.

Putting cutouts is like having loose knees. The force should transfer up to the strut, but the flex in the bushing, plus how it twists, transfers the energy to the subframe. We want a good pivot, not flex & twist. The flex and twist can lead to wander, following the road crown too easily, and being swayed by the wind easily….these make the driving more dangerous and exhausting. Gripping that steering wheel to continuously make corrections brings white knuckles, then add the heavier steering that a Volvo XC90 brings.

Add that polyurethane is resistant to salt, oil, chemicals, etc., it won’t fail like the rubber bushings will.

Again, you can update your own knowledge by watching the XC90 bushing flex. Literally all XC90 owners who have polyurethane have great reviews and they just work. Also literally, all of those who said anything against the poly in the XC90 have not tried it.

[chitownV]

Here is one video showing how much rubber bushings can flex with the cutout. Look how big those cutouts get when flexed. This can contribute to the “jiggle” in a suspension, change in toe while driving, affect tire wear, and lead to wandering.