3rd Gen Lexus RX hard suspension (merged threads)
09-13-23, 11:57 PM
#586
If you want a softer ride do not get Lexus OEM rear shocks.
Instead either get Bilstein B4 rear shocks, see link below. Part no. BILSTEIN 19282862. As explained in many other threads, these are officially listed for the 2014-18 Toyota Highlander which has the same rear suspension as the 3rd generation RX. Many members have installed them and complimented them on the improvement in ride and handling. These would be my first choice. The reason they are not officially listed for the RX is because Bilstein has not tested them on an RX. FYI installing the rear shocks is an easy 1 hour job for any gas station repair shop.
https://www.rockauto.com/en/moreinfo...t=7556&jsn=857
Or the Sachs 316603 rear shocks. These are even softer, I found they allowed too much body roll, but some like the cushier ride.
https://www.rockauto.com/en/moreinfo...t=7556&jsn=826
FYI the Bilstein B4 front struts that fit the RX are those for the 2011 Toyota Highlander. which has the same front suspension as the 3rd gen. RX. Rock Auto has them in stock now, although they can be difficult to locate sometimes.
Always replace the strut mount bearing when replacing the struts, maybe even the strut mount too.
BILSTEIN 22282668 B4 OE Replacement Strut Info
Front Left; Base Model;
BILSTEIN 22282675 B4 OE Replacement Strut Info
Front Right; Base Model;
Instead either get Bilstein B4 rear shocks, see link below. Part no. BILSTEIN 19282862. As explained in many other threads, these are officially listed for the 2014-18 Toyota Highlander which has the same rear suspension as the 3rd generation RX. Many members have installed them and complimented them on the improvement in ride and handling. These would be my first choice. The reason they are not officially listed for the RX is because Bilstein has not tested them on an RX. FYI installing the rear shocks is an easy 1 hour job for any gas station repair shop.
https://www.rockauto.com/en/moreinfo...t=7556&jsn=857
Or the Sachs 316603 rear shocks. These are even softer, I found they allowed too much body roll, but some like the cushier ride.
https://www.rockauto.com/en/moreinfo...t=7556&jsn=826
FYI the Bilstein B4 front struts that fit the RX are those for the 2011 Toyota Highlander. which has the same front suspension as the 3rd gen. RX. Rock Auto has them in stock now, although they can be difficult to locate sometimes.
Always replace the strut mount bearing when replacing the struts, maybe even the strut mount too.
BILSTEIN 22282668 B4 OE Replacement Strut Info
Front Left; Base Model;
BILSTEIN 22282675 B4 OE Replacement Strut Info
Front Right; Base Model;
is there any different if you have FWD or AWD? How about the rear coil spring? my previous RX has 14mm diameter spring and now I have 16mm with my RX350 2010 AWD.
Appreciate your response on this. Thanks
09-14-23, 05:39 AM
#587
Moderator
There is no difference between AWD and FWD in terms of aftermarket rear shock fitment or with the front struts.
What year and model was your old RX? I bet it was older than 2009 and thus had a different suspension as it was a different vehicle. You cannot compare them. Also those older ones had struts in back. The 3rd gen has shocks.
What year and model was your old RX? I bet it was older than 2009 and thus had a different suspension as it was a different vehicle. You cannot compare them. Also those older ones had struts in back. The 3rd gen has shocks.
09-14-23, 08:20 AM
#588
Someone here put FWD springs on 3rd gen AWD and recalled that there was not a significant change in ride. The transfer case and smaller rear diff are aluminum on the 3rd gen which makes the weight difference less significant on an AWD 3rd gen vs an AWD 2nd gen.
The 3rd gen needs stiffer springs and dampers because of being taller and heavier than a 2nd gen. The 4th gen I drove also has a similar ride to a 3rd gen, but with slightly better spring and shock tuning (felt less oversprung and underdamped). The 4th gen struts and shocks I put on a 3rd gen did not significantly improve the ride.
The 3rd gen needs stiffer springs and dampers because of being taller and heavier than a 2nd gen. The 4th gen I drove also has a similar ride to a 3rd gen, but with slightly better spring and shock tuning (felt less oversprung and underdamped). The 4th gen struts and shocks I put on a 3rd gen did not significantly improve the ride.
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Chamnane (09-14-23)
09-14-23, 07:42 PM
#589
Hi Clutchless, my previous RX was 2005 RX330 FWD. if I remember correctly, the front spring was 16mm while the rear was 14mm. Indeed, the front and back has strut instead of shock. at that time, I installed both front and back with KYB with factory spring and it ride very smooth. I thought I could do the same with my 2010 RX350 AWD but the result are much different.
I think I have 2 options now:
1. Replace the rear spring from the FWD one, maybe it has smaller diameter and make it softer and does not affect the car height.
2. replace the KYB shock with the Blstein one.
What do you think?
I think I have 2 options now:
1. Replace the rear spring from the FWD one, maybe it has smaller diameter and make it softer and does not affect the car height.
2. replace the KYB shock with the Blstein one.
What do you think?
Last edited by Chamnane; 09-14-23 at 07:45 PM. Reason: added more word.
09-14-23, 07:46 PM
#590
Someone here put FWD springs on 3rd gen AWD and recalled that there was not a significant change in ride. The transfer case and smaller rear diff are aluminum on the 3rd gen which makes the weight difference less significant on an AWD 3rd gen vs an AWD 2nd gen.
The 3rd gen needs stiffer springs and dampers because of being taller and heavier than a 2nd gen. The 4th gen I drove also has a similar ride to a 3rd gen, but with slightly better spring and shock tuning (felt less oversprung and underdamped). The 4th gen struts and shocks I put on a 3rd gen did not significantly improve the ride.
The 3rd gen needs stiffer springs and dampers because of being taller and heavier than a 2nd gen. The 4th gen I drove also has a similar ride to a 3rd gen, but with slightly better spring and shock tuning (felt less oversprung and underdamped). The 4th gen struts and shocks I put on a 3rd gen did not significantly improve the ride.
09-15-23, 12:11 AM
#591
update...I finally got my ride fixed, it now rides smooth as it should! I put a set of used 2015 fwd springs on and now it rides fantastic! it doesn't sway or ride to soft,its just perfect. I even hooked my trailer (2500lbs) to it and it still rode great with no swaying. I found the springs on e bay for 60$ and paid 60$ to have them installed,i still keep 32lbs air in the tires (18" Michelin) its like a different car. I hope this works for any of you who want to try it as well.
09-15-23, 11:46 AM
#592
Good to hear someone had success with it and actually noticed an improvement. I read about it on an RX350 Facebook group but unfortunately I lost where the actual post was. You will definitely experience more sagging with cargo and understeer if you do this to the car though, which the RX already has a bit more of than I'm happy with from the factory. I know 4th gen springs can fit too, but I never tried this.
There's more to the spring than just thickness alone. There's the amount of coils, how tightly wound they are, etc, so it's not possible to just judge it based on coil diameter alone
There's more to the spring than just thickness alone. There's the amount of coils, how tightly wound they are, etc, so it's not possible to just judge it based on coil diameter alone
09-15-23, 12:12 PM
#593
There may be published spring rates but I would see if you could find results for the 3rd gen and 4th gen RX and compare. They might have made the 4th gen rear springs softer due to complaints about ride quality. The 2014-2023 Highlander rear springs can fit as well, but there is no way of knowing if they will change ride height or not. I can say for sure though that I've driven a 2014 Highlander AWD and it rides better than the RX.
09-19-23, 02:50 AM
#594
I decided to go with Bilstein B4 19282862 to replace my KYB rear shock, already ordered and hope it arrive next week. The only concern for me if I'm having KYB at the front and not sure how the front and rear would interact. I read some thread here that I should have all 4 as same brand & type but I don't want to spend more to replace the front as it seem ok to me. the harshness really come from the rear as many have pointed out.
09-19-23, 06:49 AM
#595
Moderator
Your vehicle will drive, handle and ride just fine with KYB in front and Bilstein B4 in the rear. You may even decide to leave the springs alone after experiencing the Bilstein ride. Let us know what you think after driving on them for a couple of weeks and breaking them in.
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Chamnane (09-21-23)
10-03-23, 12:07 PM
#596
Hi @Clutchless
I hope you are doing well. The ride in my 2010 AWD base model is completely shot. From swaying side to side when turning into and hitting the lip of a driveway, to bouncing change out of the door when hitting bumps on a straightaway. If you have a few minutes to spare, I would love to pick your brain a bit. Please.
- Stock everything except for some KYBs I stupidly put on the rear about a year ago.
- 18 month old 16" Michelin Defenders 80k mile.
- I work out of it. Once a week on average I will load up 200-500 pounds of tools. Once a month I am hauling my little single axle trailer. With as much as a ton loaded on it. Though usually it's just a few hundred pounds. And some of those times I am doing both, especially when starting a new job. I haul in 'spurts' if that makes sense.
- It's never had an alignment. At least not since I purchased in '14 with around 30k on it. And I would truly like to keep it that way.
My plan of attack after reading the last few pages of this awesome thread....
-Bilstein B4s all the way around.
-OEM strut mounts/bearings
-Possibly sway bar links. Are all links the same? Meaning will I absolutely have to get it aligned if I replace?
Questions:
Any specific brand of sway bar links? Or just don't get the cheapest thing I can find.
-Is there anything else.... such as bushings, coil insulators, and the like? Where replacing will give me a noticeable difference?
Thanks a ton.
I hope you are doing well. The ride in my 2010 AWD base model is completely shot. From swaying side to side when turning into and hitting the lip of a driveway, to bouncing change out of the door when hitting bumps on a straightaway. If you have a few minutes to spare, I would love to pick your brain a bit. Please.
- Stock everything except for some KYBs I stupidly put on the rear about a year ago.
- 18 month old 16" Michelin Defenders 80k mile.
- I work out of it. Once a week on average I will load up 200-500 pounds of tools. Once a month I am hauling my little single axle trailer. With as much as a ton loaded on it. Though usually it's just a few hundred pounds. And some of those times I am doing both, especially when starting a new job. I haul in 'spurts' if that makes sense.
- It's never had an alignment. At least not since I purchased in '14 with around 30k on it. And I would truly like to keep it that way.
My plan of attack after reading the last few pages of this awesome thread....
-Bilstein B4s all the way around.
-OEM strut mounts/bearings
-Possibly sway bar links. Are all links the same? Meaning will I absolutely have to get it aligned if I replace?
Questions:
Any specific brand of sway bar links? Or just don't get the cheapest thing I can find.
-Is there anything else.... such as bushings, coil insulators, and the like? Where replacing will give me a noticeable difference?
Thanks a ton.
Last edited by needa; 10-03-23 at 02:22 PM.
10-03-23, 04:52 PM
#597
Moderator
It sounds like you have most things covered. Are you doing the work yourself? Have you replaced struts? Have you used a spring compressor?
Do you really have 16 inch wheels on your RX? If so that is part of the problem. OEM wheels were either 18 inch or 19 inch. I hope it was a typo.
How many miles are on it?
You could get the Bilstein B4 struts and shocks. However given your load carrying, I would get B6 struts and shocks as they are stiffer. It will still ride better than KYBs. Especially with 16 /18 inch tires.
You will need an alignment after replacing the struts. You usually do not need spring seats or coil insulators on the struts unless yours are torn. So give it a look.
However you need a reliable independent foreign car (Japanese or Toyota) specialist to inspect your suspension in case there are other issues such as worn rear trailing arm bushings which are a known problem and you just replace the rear trailing arm. I used Mevotech ones from Rock Auto. You could also have bad front control arms, ball joints, etc.
Both rear sway bar links are the same, as are both front sway bar links. But the fronts and rears are different. If the rear ones are okay, leave them alone.
Any brand will do, although I prefer to use reputable brands and prefer those with bolts on the ends, not Allen inset screws like the OEM ones that strip after they get rusty!
You often have to replace the front sway bar links when replacing the struts as they are so rusted they cannot be unbolted and have to be cut off. I had to cut mine off. Leave them bolted to the struts and just cut the end on the car. I would replace them even if you can unbolt them.
This is no problem for a shop, or if you have a hand held grinder. If doing any of the work yourself spray everything with PB Blaster several times over several days to loosen up the bolts. Regarding the front struts, you need a strut compressor and it is a dangerous job. Not something to learn on. All repair shops do strut replacement all the time and have commercial spring compressors that can do the job in a minute.
This info was posted by MattRX regarding spring upgrades. The hybrid spring may be an option: It is post 557 ont his thread. I bet some local junkyard or ebay would have them.
The towing package has regular springs, but it got a transmission oil cooler, engine oil cooler, thicker radiator and a few other goodies. The AWDs however did get thicker springs, with the 450h hybrid models getting even stiffer ones with an extra coil. The 4th gen RX rear springs should fit as long as you use that generation's rubber spring isolators. These springs have an extra coil than our gen, but they do appear taller so you would probably gain ground clearance.
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Do you really have 16 inch wheels on your RX? If so that is part of the problem. OEM wheels were either 18 inch or 19 inch. I hope it was a typo.
How many miles are on it?
You could get the Bilstein B4 struts and shocks. However given your load carrying, I would get B6 struts and shocks as they are stiffer. It will still ride better than KYBs. Especially with 16 /18 inch tires.
You will need an alignment after replacing the struts. You usually do not need spring seats or coil insulators on the struts unless yours are torn. So give it a look.
However you need a reliable independent foreign car (Japanese or Toyota) specialist to inspect your suspension in case there are other issues such as worn rear trailing arm bushings which are a known problem and you just replace the rear trailing arm. I used Mevotech ones from Rock Auto. You could also have bad front control arms, ball joints, etc.
Both rear sway bar links are the same, as are both front sway bar links. But the fronts and rears are different. If the rear ones are okay, leave them alone.
Any brand will do, although I prefer to use reputable brands and prefer those with bolts on the ends, not Allen inset screws like the OEM ones that strip after they get rusty!
You often have to replace the front sway bar links when replacing the struts as they are so rusted they cannot be unbolted and have to be cut off. I had to cut mine off. Leave them bolted to the struts and just cut the end on the car. I would replace them even if you can unbolt them.
This is no problem for a shop, or if you have a hand held grinder. If doing any of the work yourself spray everything with PB Blaster several times over several days to loosen up the bolts. Regarding the front struts, you need a strut compressor and it is a dangerous job. Not something to learn on. All repair shops do strut replacement all the time and have commercial spring compressors that can do the job in a minute.
This info was posted by MattRX regarding spring upgrades. The hybrid spring may be an option: It is post 557 ont his thread. I bet some local junkyard or ebay would have them.
The towing package has regular springs, but it got a transmission oil cooler, engine oil cooler, thicker radiator and a few other goodies. The AWDs however did get thicker springs, with the 450h hybrid models getting even stiffer ones with an extra coil. The 4th gen RX rear springs should fit as long as you use that generation's rubber spring isolators. These springs have an extra coil than our gen, but they do appear taller so you would probably gain ground clearance.
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Last edited by Clutchless; 10-05-23 at 10:00 AM.
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needa (10-05-23)
10-05-23, 10:42 AM
#598
@Clutchless
Thanks a ton for the detailed response. Ahh yes,.. they are 18". I have 16's on my old Rav.
Rock Auto sent me an email this morning letting me know the b4 rears are back in stock. So I ordered while I could. I hadn't seen your post yet. Though I already knew you were going to suggest the B6es because of my hauling needs. Oh well. At least I'll get to see what the b4s can do for the ride quality, even if it's short lived.
I have replaced struts on three of my vehicles over the last thrity'ish years. The first time I didn't have springs compressors... there was no internet back then and of course... I was young and dumb. ""I didn't need no stinking spring compressors"". But I do have them now and boy howdy do they make the job easier/safer.
158k miles. I'm going to go to neighbor's place. They have lvl concrete. To jack this thing up and inspect everything. Anything questionable I will get online and compare what it looks like with ones that need replacing... seeing as I have to get an alignment no matter what. Paying particular attention to the rear trailing arm.
I'm pretty sure the rear springs are sagging a bit. Might not be. But the car does look like it's squatting in the back a touch. I think I'll take a measuring tape and compare the tire clearance to other 350s I see in parking lots. There are still quite a few in my area. This might not be the most scientific idea... but it's all I got. lol.
I can't thank you enough for the help. Be well and stay safe out there.
Thanks a ton for the detailed response. Ahh yes,.. they are 18". I have 16's on my old Rav.
Rock Auto sent me an email this morning letting me know the b4 rears are back in stock. So I ordered while I could. I hadn't seen your post yet. Though I already knew you were going to suggest the B6es because of my hauling needs. Oh well. At least I'll get to see what the b4s can do for the ride quality, even if it's short lived.
I have replaced struts on three of my vehicles over the last thrity'ish years. The first time I didn't have springs compressors... there was no internet back then and of course... I was young and dumb. ""I didn't need no stinking spring compressors"". But I do have them now and boy howdy do they make the job easier/safer.
158k miles. I'm going to go to neighbor's place. They have lvl concrete. To jack this thing up and inspect everything. Anything questionable I will get online and compare what it looks like with ones that need replacing... seeing as I have to get an alignment no matter what. Paying particular attention to the rear trailing arm.
I'm pretty sure the rear springs are sagging a bit. Might not be. But the car does look like it's squatting in the back a touch. I think I'll take a measuring tape and compare the tire clearance to other 350s I see in parking lots. There are still quite a few in my area. This might not be the most scientific idea... but it's all I got. lol.
I can't thank you enough for the help. Be well and stay safe out there.
10-05-23, 01:24 PM
#599
Moderator
If the rear shocks were leaking that could explain the sag.
I hope you have a cordless impact driver etc that you can attach the socket to as it makes compressing the springs a lot faster. I actually killed the battery doing mine a few years ago with a Milwaukee 18 volt impact driver. Luckily I had 2 batteries! That thing got so hot! So make sure you grease the threads on the spring compressor!
Now I also have a Ridgid high power torque wrench that appears to be more powerful. Great for rotating the tires! Haven't had to replace any more struts yet.
I hope you have a cordless impact driver etc that you can attach the socket to as it makes compressing the springs a lot faster. I actually killed the battery doing mine a few years ago with a Milwaukee 18 volt impact driver. Luckily I had 2 batteries! That thing got so hot! So make sure you grease the threads on the spring compressor!
Now I also have a Ridgid high power torque wrench that appears to be more powerful. Great for rotating the tires! Haven't had to replace any more struts yet.
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needa (10-07-23)
10-05-23, 01:32 PM
#600
I can't speak for B4 on an RX350, but I tried them on my friend's 2011 RAV4 after I put Lexus NX200t springs on it. Got rid of the crazy nose dive during braking and sagging when accelerating, plus made the cornering far better. They ride surprisingly plush yet still limit roll when pushed (car still rode better than a stock RX350). I view them as a superior version of a KYB Excel-G. Equal or slightly better cornering with more comfort. The KYBs have a pretty strong rebound, but the B4s are more linear and smooth in their motion compared to the KYBs.
For heavier loads the RX450h rear springs are an option, and even the 4th gen rear springs. I helped someone in Europe source some 4th gen springs for his 3rd gen RX450h after his originals collapsed from a combination of rust and towing. The 4th gen ones rode nearly the same but gave him less sag when carrying heavier loads, he said there was hardly a comfort change either. Rear springs from a 2014-2019 Highlander could fit too but that may make the rear ride higher. On a 2010 RX350 I even put 4th gen RX struts and rear shocks from KYB but it mainly rode the same. I think the spring rate on these cars is more to blame than the strut's valving itself.
For heavier loads the RX450h rear springs are an option, and even the 4th gen rear springs. I helped someone in Europe source some 4th gen springs for his 3rd gen RX450h after his originals collapsed from a combination of rust and towing. The 4th gen ones rode nearly the same but gave him less sag when carrying heavier loads, he said there was hardly a comfort change either. Rear springs from a 2014-2019 Highlander could fit too but that may make the rear ride higher. On a 2010 RX350 I even put 4th gen RX struts and rear shocks from KYB but it mainly rode the same. I think the spring rate on these cars is more to blame than the strut's valving itself.
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needa (10-07-23)