konradl

I've only had the LS about 2 months and on day one, I right away noticed how smooth the car was over bumps, but also a bit floaty. Now as I am more used to driving it, it has really come to my attention that it has some body roll and when at higher speeds on the highway, when I hit dips it really floats/bounces (up/down/up/down) till it stabilizes itself. However, it still absorbs potholes fairly well, I guess.

On a regular car, I would right away know it's the struts, but I'm a bit hesitant to make that call here, even though I'm really leaning towards the front, and possibly the rear, struts being shot. Even though it's a smooth luxury car, I'm pretty sure it shouldn't be floating and bouncing around like that. I know they're not known for a very aggressive suspension setup.

So I wanted to ask if anyone/everyone is experiencing this bounce at highway speeds, or if my struts are actually done.

If they are, I've read about people complaining about the non-factory struts making the car sit higher than the stock, factory KYB struts, and that they are stiffer. The car actually sits fairly low now, which I think is another indicator of blown struts.
Can anyone that has installed the non-factory KYB comment on them - ride quality and height? Is there a big difference in price between factory and non-factory KYBs?

Any input is much appreciated.

Devh

How many miles are on the LS?
A non stabilizing bounce is a good indication that the struts are shot.

I have the non air and my car does not bounce but it does have it's share of body roll at the limit which is completely normal.

konradl

I'm also leaning more towards worn struts. The car has 119k on it.

Devh

A great deal of dampening is lost at around 80k miles but it is not felt until after 100k.
I would say the struts did their job and are in need of replacement. like any other car.

The anecdotal impressions of the KYB replacements are misleading. Anytime you replace new struts they will be stiffer then the old and it can be felt. They will also ride higher for a few months until they settle down. After the break in they will ride just fine and you will get use to them.

konradl

I hope you're right Devh and it would only make sense, as KYB only lists one type of front strut on their website 551122. I also looked up front struts on oem lexus parts website and it interchanges into the the 551122 number. I may be wrong, but I don't think there is any other KYB factory strut being made for it at this time.
I guess I should just pull the trigger on these and I'm sure they'd settle after a few hundred miles, especially with the potholes we have around here.

Devh

I believe KYB might be the original manufacture of the struts as they are for many Toyota vehicles.
Keep in mind however that your replacement is only as good as the other components that complement it such as the strut bearing plate rubber and the control arms. I would inspect those items as well and replace and refresh the suspension if necessary.

justjosh

iTrader: (5)

I am experiencing the same floatiness on the highway in my 08 LS600hL with air suspension. I have a feeling all of my air struts need replacement. I will be bringing it in to the dealer in a few weeks for diagnosis.

enoch861

I'm trying to figure out how air suspension would "wear" out. I mean unlike the stuff in normal shocks that can leak out and what not, air struts use air and the more air you add into the shock the stiffer the ride gets and vice versa. So in that case only other suspension parts such as control arms/bushings would fail unless the strut itself fails and starts leaking air or the compressor is wearing out.
Or am I thinking about this completely the wrong way?

Devh

Air suspension is still a hydraulic suspension. The only difference is the use of an inflatable cushion and a proportional valve. These suspension systems can be problematic primarily because mono tube suspension can prove unreliable even without an air set up.

The regular shocks in the LS are twin tube designed and are tried and true for reliability. They are more likely to wear out evenly then catastrophically.

konradl

Just wanted to follow up on this subject in case someone is on the fence or has to do their struts also.

Over the weekend, I installed the KYB 551122 front struts and all worked out well. I think one of my old struts was shot. The car does ride a bit firmer then previously, although it still floats a bit at highway speeds - maybe I'm just not used to the cloud ride yet. It also seems to absorb bumps and holes better then with the old ones.

Installation was a bit of a PITA and took me longer then it should, because of the springs compressors I've rented from Advance Auto Parts. The hooks that grab and grip the spring coil were a bit large and I had a hard time fitting them between the coils. By the time I got to doing this step, they were closed, so I was stuck. For anyone doing this in the future, please note and get the ones with the smaller/thinner hooks.

I ended up taking both upper control arms off and leaving the sway bar connected. Once I lifted both sides of the front of the car up, the sway bar dropped, allowing me to push the spindle down with my foot, and/or help of a friend, and remove the strut.

After installation, the next day, I took the car in to Firestone to get a road force balance and an alignment. I got lucky, because they were doing a 'pothole special' where they do the alignment, regular balance and tire rotation for $89, which is a good deal. The guy was cool and honored it even with the road force balance.

With new struts, alignment and balance, the car rides is much improved and smoother. Got the struts off ebay for $180 new (best offer submitted) and $100 for Firestone. $280 well spent with a bit of time.
Today or tomorrow, I will be installing new pads and overdue rotors in the front to eliminate the vibration during braking.

Hope this helps for anyone looking to tackle their front end in the future.

I8ABMR

I traded my LS a little over a year ago and she only had 65K on it and had the float. On dips in the freeway the nose would float a bit. Could be the suspension set up. I would have a tech check it out or try to bounce the car when parked. It may still be normal considering the LS ride. I ditched my LS because I was tired of the float and I wanted to hit the track. Still miss the Huge LS but the ISF is a beast

konradl

Thanks for the feedback. That's exactly what mine does on the highways. It gets a bit annoying, especially when it hits dips on curves with higher speeds and tries to float away instead of sticking to the curve on a turn. The S class I had a few years back handled curves great.

I'm wondering if Tannabe springs reduce this effect. I'm sure the coilovers do, but I'm not looking for a stiff ride either.

Devh

I don't have anything like what you describe and I'm very much in touch with suspension systems and behavior. I'm also a previous BMW owner that enjoyed a more controlled car. The LS can be boaty around low speed turns but it's road manors is pretty good for high speed maneuvering, in fact it's effortless which is what a luxury car is suppose to bring to the table.
It sounds like to me to be an alignment issue or a tire issue.

konradl

Maybe it's just the difference in road surfaces, as other members have experienced similar behaviors. Alignment wouldn't have anything to do with it - it's the bouncing/floating when going over dips on the highway.
I've come to the conclusion that this is just the way the LS is supposed to be with the regular suspension - elastic and a bit springy on the highway. Other than that, the ride is very smooth.

Nospinzone

Great info konradl. I have 85K on my car and do not experience the "bouncing/floating" yet, but I'm sure it is a matter of time. I will keep this thread in mind.