When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
So... I'm at a bit of a loss here. I replaced the front shocks earlier this week and it's ruined the ride of the car. I replaced the shocks because I believe the mounts were making a ton of noise and after 20 years, I wanted to refresh them after how much I enjoyed the improvement from replacing my lower ball joints. I'm so close to getting that perfect Lexus "glide".
I went with aftermarket KYB shocks 341159 and Lexus OEM mounts & boots. Re-used the springs since they were still totally fine, and in all my research a lot of people seem to re-use them (even with 200k, 300k on the clock). I only replaced the front shocks, as the rears seemed to be holding up well enough.
There is virtually zero suspension compression in the front now. Even driving down the smoothest of roads, I feel the fat around my body jiggling from how much the car is bouncing around. Hitting bigger bumps at speed causes my car to "jump" as the front end gets launched into the air and the tires lose grip with the road. It feels like the car is riding on the springs with zero damping at all. These were supposed to be a OEM replacement, but instead I feel like I'm driving a Porsche GT3 RS! That's the only ever car I've been in that rides this stiffly. I get that symptomatic "pogo stick" that you get from too-stiff shocks. The ONLY thing I replaced was the shocks, nothing else got touched.
I supplied the parts, a local shop did the install. As far as I can tell, everything they've ever done has been installed correctly (so far). If I put my entire 200lb bodyweight on my front fender, the damper compress less than one inch and feels stiff as a rock.
Are these shocks defective? There shouldn't be much of a break-in period, and even then, getting slightly softer over time will never fix this awful ride. Did I miss something? Should the springs have been replaced (the forums and my shop agreed they didn't need to be). What can I do? I... really would appreciate some help here because the car drives great, but the ride is horrible now. My friends 2006 Chrysler Sebring has a smoother ride than this at the moment...
My suspension is completely stock (not lowered) and I'm running OEM 16'' wheels.
Final update, figure I would share this for anyone who comes across this thread in the future. It took me about a month to get to the bottom of this because life became rather busy, I wanted to do the motor mounts first and isolate this problem, and my shop agreed to do the work for free if we scheduled it out a little further. Okay, not the end of the world. I can work with that.
As I alluded to above, I emailed KYB support, explained my issues. Their reply was the following:
Hello,We are very sorry to hear that you ran into this issue. We designed these struts to be within 10-15% of the OEM damping rates for increased roll control and improved handling, but without sacrificing ride quality. We try to be more stringent about this on Lexus applications which are generally not meant to be firm ride vehicles.
It’s possible the struts are locked out and not compressing, and that is why they feel so firm. This can happen if the struts are installed with the vehicle in the air and the full weight of the suspension hanging down on the struts. Since struts are designed to be dampeners of motion rather than load bearing components, this could be an issue especially on larger vehicle where the unsprung weight is significant. To try and help alleviate this condition, you would need to loosen (but not fully remove) the top piston rod nut and upper mounting points, then slowly set the vehicle on the ground, bounce it up and down a few times using your body weight, then tighten everything back up to the OEM torque specification.
This will help break the strut loose and allow it to settle on your car, so I would recommend starting here to see if that will improve the ride.
And you know what, it ****ing worked. Pulling out of the parking lot I noticed a difference, and by the time I made it a block I knew this had solved it. The glide is back! The stiffness in the rebound at the front of the car is completely gone, it no longer feels like some super stiffly dampened sports car. It's kind of shocking the difference and I'm glad that I refused to accept that the car wasn't driving like it should. But I'm just glad the saga is over and finally, after 3 months of working since the winter storm & ice killed my front suspension, the rebuild is complete. Sway bar bushings, lower ball joints, the entire shock assembly, motor and transmission mounts. It's unbelievable how fresh it rides now. My shocks weren't broken, the mounts were though and making quite a bit of noise and had a lot of play. The biggest ride quality improvements came from lower ball joints and the motor\trans mounts.
For those of you who have had experiences in GT3 Porsches, Subaru WRX and specifically the Ford Focus RS; that is the level of stiffness in the dampers I was experiencing. Instead of "falling" into a bump like normal cars do, this level of stiffness actually pushes you "up" on smaller bumps causing some really nasty ride quality issues. The car would actually get pushed up from these small insignificant bumps, showing that the dampers actually weren't compressing at all until you hit them with a big enough load where they would compress.
Side note: does anyone know why this worked? I don't understand the geometry of why doing this process would soften up the ride. Was there an error in the install process of my shop that caused the shocks to become a load-bearing component? Is this a non-standard practice they had me do compared to most other normal cars? If I had to guess, it sounds like during the install when the suspension was hanging in the air, this applied a slight torque in the mount\top where the shock mounts to the body. And when the bolts were torqued down, this caused the geometry to be ever-so-slightly out of alignment. Enough to cause the shocks to become load bearing. Am I on the right track here?
Yeah that was one of the threads I came across. He only did the initial impression, which didn't really describe much. Just one sentence saying. And since I had a "professional" install it, I know it's not his first suspension replacement job.
This isn't too stiff though... this is borderline non-functional. Re-using springs wouldn't do this, no?
I used those exact KYB 341159 front struts on my '91. Rears (341268) as well, new KYB mounts, etc. I had no problems at all installing things myself, and thought they were great, immediately. No break in period. Still doing great 10 years later. Am still on the original springs too, now at 202k miles.
Almost all of the spring force comes from the springs. For example, a little over 1000 lbs per spring on a 4000 lb car. (more than 1/4 due to the spring being inboard of the tire).
The struts are primarily for damping - they provide a force proportional to the rate of strut extension. So they smooth things out but should not provide much spring force.
They are charged with Nitrogen gas, and that pressure does provide some spring force, but it is probably closer to 40 lbs vs. the 1000 lbs from the springs. The gas charging does not try to provide a spring force, that just comes along whether you want it or not. The purpose of the gas is that keeping the oil under pressure will keep any bubbles small. So if you're really working the struts, racing or driving over rough roads, without N2 pressure in there, bubbles would form, negatively impacting the oil's ability to provide the damping needed. Keeping the bubbles small means the oil still acts like oil, rather than gas.
So given all that, the fact that you can't sit on your fender and compress the suspension like you did before is a problem. It should feel basically the same as it did before. I will guess there was some installation error. Maybe something is binding.
So given all that, the fact that you can't sit on your fender and compress the suspension like you did before is a problem. It should feel basically the same as it did before. I will guess there was some installation error. Maybe something is binding.
Sir, thank you for this detailed breakdown. I already knew the purpose of shocks (to control rebound), but I didn't know the exact mechanism that the gas is used to control the bubbles. I understand the valving in the shock itself has a big effect on this as well, and it's how you get your different rebound rates and such.
Yes. My bodyweight can compress the rear of the car about 3-4x more than the fronts. Maybe more, hard to tell without viewing from a distance.
It's to the point that on the highway at higher speeds (70-80), larger bumps during turns upset the car and I feel the rear "rotate" around due to these different spring rates. It is rather unsettling the first time it happened, and it almost was so bad that the car "snapped" back to traveling in it's intended direction. It's difficult to describe. It is a feeling I've never felt in all of my years of driving.
Do you think this has anything to do with me re-using the OEM original springs? With all the literature here on this forum, in my research, I came across tons of people re-using them and never saw any warnings about re-using them.
How would you recommend me approaching the shop about this?
I think something must be defective with your shocks. Do you know if the shocks you received were old stock sitting on the shelf? I sold my 97' LS with 300k in April of 2019, so I put on roughly 25k miles of driving on the KYB Excel Gs, 10k miles of which were in ****ty Michigan potholed roads and the shocks still held up fine in the hot climates of AZ and the freezing temperatures of MI.
If you're experiencing the "pogo stick" type of ride, I believe that something inside the shock is locked up or possibly broken. I had this very stiff, almost no compression ride on my 1997 Odyssey after the car was lifted in the air and the shocks hyper extended and froze in that extended position, almost as if the piston wouldn't go back into the shock body in perfect alignment. I suspect that the valve internally broke apart and wouldn't move the fluid beyond that point causing this. It was only my driver side shock that did that, but this was after 195k miles of use, being original to the van.
The KYBs ride a little stiffer than the OEM Lexus shocks but it shouldn't feel that harsh. I recently did the Bilstein HD shocks in the Front of my 99' LS and the ride is Lexus smooth. I can't tell a difference in damping compared to my 151k mile OE Lexus shocks aside from the nose dive being eliminated under braking and the side-to-side effect being better controlled, which new shocks would do.
I doubt re using the original springs is the issue. But how the installer re used them might be...
Are you able to check if the springs are oriented correctly on the spring support? See attached pic-
I don't know anything about the shop doing the work but there is a bit of finesse getting this correct. If you don't get it right the first time a lazy tech can easily call it good enough...
I doubt re using the original springs is the issue. But how the installer re used them might be...
Are you able to check if the springs are oriented correctly on the spring support? See attached pic-
I don't know anything about the shop doing the work but there is a bit of finesse getting this correct. If you don't get it right the first time a lazy tech can easily call it good enough...
Is that diagram universal to both left and right sides of the car? My drivers side coil spring is pointed inboard, directly towards the engine block. My passenger coil spring is pointed in the opposite direction, outboard, directly toward the wheel (exactly how it appears in that diagram).
They both do not appear to be randomly oriented, they both are directly pointing either inboard or outboard.
If this were the problem, and one of them is incorrectly oriented, you would expect un-even response as one of them is functioning correctly while the other is the one giving the problem. But that is not the case. Both sides are equally stiff.
Hopefully this picture shows three things:
1) that my coil springs are rust free and honestly in amazing condition
2) that the drivers side coil spring is pointed inboard, directly towards the engine, 180 degrees opposite to the diagram you shared.
3) I have a couple hundred winter miles on these, so things are a bit dirty and it was difficult getting a clean picture
Originally Posted by Losiracer2
I think something must be defective with your shocks. Do you know if the shocks you received were old stock sitting on the shelf?
So, long story short, I ordered each shock individually, about a week apart. The boxes appear brand new, with no warehouse dust and zero dents in the boxes. I can understand one shock being defective, but two shocks with identical failure symptoms seems unlikely. Otherwise, I do not know how old the physical units are and the boxes have no manufacturing date stamped on them. I'm not sure if the shocks themselves have a stamp, but I don't have jacks to really get a good look at them.
And yes, I double checked the part numbers on the physical boxes before delivering them to my shop. They were the correct 341159 parts.
Originally Posted by Losiracer2
The KYBs ride a little stiffer than the OEM Lexus shocks but it shouldn't feel that harsh. I recently did the Bilstein HD shocks in the Front of my 99' LS and the ride is Lexus smooth. I can't tell a difference in damping compared to my 151k mile OE Lexus shocks aside from the nose dive being eliminated under braking and the side-to-side effect being better controlled, which new shocks would do.
I felt the difference in stiffness pulling out of the parking lot, it was a night\day. A lot of other dynamics improved, I fixed the noise issues I was having, braking is WAY better, the car feels sharper and the front end feels way tighter and more controlled. The only issue is with how stiff the suspension now is. It's not a "slight" increase in stiffness, we're talking several times more resistance to compression than how it was before. And my shocks weren't completely broken when I replaced them. They were primarily noisy\clunky (I suspect the mounts\boots), but I think they were still doing most of their intended job at probably 80-90%.
Is that diagram universal to both left and right sides of the car? My drivers side coil spring is pointed inboard, directly towards the engine block. My passenger coil spring is pointed in the opposite direction, outboard, directly toward the wheel (exactly how it appears in that diagram).
They both do not appear to be randomly oriented, they both are directly pointing either inboard or outboard.
If this were the problem, and one of them is incorrectly oriented, you would expect un-even response as one of them is functioning correctly while the other is the one giving the problem. But that is not the case. Both sides are equally stiff.
The pic above is for general reference not necessarily LS400 specific (I was away from my laptop and DL'd a random pic)
Here's the PDF from the 2000 LS svc manual. Pay attention to the photos in sa-24.
The coil springs are L and R specific so they are not exactly the same but they should mirror each other. Where the bottom of the spring rests is the important thing to look for. If it's not seated in the little divot provided in the support it's not positioned correctly.
The pic above is for general reference not necessarily LS400 specific (I was away from my laptop and DL'd a random pic)
Here's the PDF from the 2000 LS svc manual. Pay attention to the photos in sa-24.
The coil springs are L and R specific so they are not exactly the same but they should mirror each other. Where the bottom of the spring rests is the important thing to look for. If it's not seated in the little divot provided in the support it's not positioned correctly.
I'm not an expert (obviously lol)... but would you consider these correctly positioned? These are the best pictures I can get of each.
Pass side looks great, drivers side shows a little room for improvement but prob not enough to cause the issue you're describing.
Fair. The fact that it's exhibited on both sides has just perplexed me thus far and really ruled out a lot of things. Well, I appreciate your input sir.
I've heard of suspension preload though I haven't dealt with it myself. There's certain bushings that you want to preload before you tighten everything down, in other words you don't want to tighten down certain suspension parts (like certain bushings) while the vehicle is up in the air and there is no load on the suspension, you want the suspension to be under the load where it would be if it where seated on the ground under it's own weight then tighten certain suspension parts down. Though this is mostly an issue with certain bushings that can affect the ride, just replacing shocks I don't know if they needed to loosen other parts of your suspension or not but maybe there's something there maybe not. It's just something that crossed my mind reading this and my thinking could be totally off on this just figured I'd throw it into the thread as an outside possibility.
Good luck solving this. I agree with all the other advice you're getting here (spring alignment not perfect but probably OK, etc.).
On your question above specifically about spring reuse ... I'm still going on my originals at 202k miles, with no problems. And the springs in your pics look visually perfect, so it's not like they're dead due to rust.
On the suspension preload, I don't think anything should have been touched that needed that, but it is a doubt to consider. If the guy installing things was really confused ...
Some measurements might help - measure center of hub to fender lip on all 4 corners, both in normal state parked on flat level ground (e.g., parking lot) and with you or a friend sitting on the fender above the wheel.
I know my struts were silver, not black, but I did buy them 10 years ago. Thinking what could possibly be wrong with the parts ... (although, getting them from two different sources, and with the problem apparently present on both sides, it actually suggests the parts are good) - any chance you can find a part number stamped into the strut cylinder? Hopefully you still have the old ones. If so, measure the distance from the spring seat to the lower bushing hole centerline, and compare those measurements old vs. new.
The installer should definitely have done a side by side comparison before continuing, but ...
Beyond that, I can't really see what went wrong unless it was installation error. And that could mean bending the shaft, etc. Any signs of wheel well collateral damage from a wrestling match?
If you don't get anything figured out very soon, I'd take it back to the shop. This should be a very easy job, and since the problem is so easily seen - both sitting on the fender when parked and when driving - they should know there is a problem, and never should have released it back to you in that state.
12-31-19, 04:53 PM
Brand new KYB shocks feel like pogo sticks
