KDSS clunk (6 Viewers)

[coltondesmond01]

Hello, I’m brand new to this forum and forums in general. I have a 2012 GX 460 and I’ve had a clunk for a while now. Developed pretty fast after I first got it in early 2021. It definitely is coming from the driver side front KDSS ram. I can have someone rock the car while I’m under there. I am just installing UCAs and noticed a grease zerk on top to the KDSS ram and am wondering if that might help. I can’t find anything anywhere on the internet that acknowledges it. I just don’t want to throw grease in there and realize it’s a KDSS fluid bleed port or something disguised as a zerk.

Does anyone know about this zerk and if grease is needed in there? Or has anyone experienced a clunk coming from the KDSS? I off-road it quite a bit, the car has been through some rough terrain so I have come to accept clunks a normal part of my driving experience

 

[coltondesmond01]

Hello, I’m brand new to this forum and forums in general. I have a 2012 GX 460 and I’ve had a clunk for a while now. Developed pretty fast after I first got it in early 2021. It definitely is coming from the driver side front KDSS ram. I can have someone rock the car while I’m under there. I am just installing UCAs and noticed a grease zerk on top to the KDSS ram and am wondering if that might help. I can’t find anything anywhere on the internet that acknowledges it. I just don’t want to throw grease in there and realize it’s a KDSS fluid bleed port or something disguised as a zerk.

Does anyone know about this zerk and if grease is needed in there? Or has anyone experienced a clunk coming from the KDSS? I off-road it quite a bit, the car has been through some rough terrain so I have come to accept clunks a normal part of my driving experience

View attachment 3320489

Here is a marked up version of the picture. I took the picture from inside the engine bay looking down. I have the battery and battery trey removed.

 

[Acrad]

That is an air bleeder

Have you confirmed if any bushings in the KDSS system & stabilizer bars need to be replaced? Not uncommon to need replacement at 10 years.

Rear #Suspension #Rattles / #Bushing Replacement - ClubLexus - Lexus Forum Discussion

GX - 2nd Gen (2010-2023) - Rear #Suspension #Rattles / #Bushing Replacement - Okay, let me see if I can properly explain this and get some of your ideas: When I drive over quick choppy bumps in pavement I get a rattle in the rear of the suspension, but only when the bump is on one side. When the...

www.clublexus.com

 

[coltondesmond01]

That is an air bleeder

Have you confirmed if any bushings in the KDSS system & stabilizer bars need to be replaced? Not uncommon to need replacement at 10 years.

Rear #Suspension #Rattles / #Bushing Replacement - ClubLexus - Lexus Forum Discussion

GX - 2nd Gen (2010-2023) - Rear #Suspension #Rattles / #Bushing Replacement - Okay, let me see if I can properly explain this and get some of your ideas: When I drive over quick choppy bumps in pavement I get a rattle in the rear of the suspension, but only when the bump is on one side. When the...

www.clublexus.com

View attachment 3320513

Ah that makes sense, now that you say it’s a bleeder screw I can recognize that. Thanks for the help!

In regards to bushings, I have checked them and replaced a few. Didn’t solve the problem. I can get someone to rock the car while under there and I can put my hand on the bottom of the kdss ram and can feel something loose at the bottom underneath the boot. I am going to pull the boot off and see if I can see anything in there.

 

[Jstawgn]

It might be coming from the cylinder itself. There been a few reports about the piston inside the cylinder coming apart.

The cylinder itself are not that espensibe. There are quite a few people that successfully charge the system back using 1000PSI hydrostatic test pump and R134a high side coupler.

 

[Banandalorian]

Are you lifted? Age, mileage, lift and driving style (i.e. off roading) could definitely wear out the KDSS piston itself, but you may also have some weird interference with the KDSS geometry due to the lift. It's possible for the sway bar to shift sideways within the mounts/bushings and then it can contact some part of the frame and/or skid plate when it moves around with suspension motion.

Also, FWIW last spring I was certain I had a clunk coming from KDSS and it turned out to be bad lower control arm bushings so check those if you haven't already.

 

[r2m]

The part the clinks when someone is rocking your rig, are you able to put your hand on it and giggle it yourself without outside influence?

 

[coltondesmond01]

It might be coming from the cylinder itself. There been a few reports about the piston inside the cylinder coming apart.

The cylinder itself are not that espensibe. There are quite a few people that successfully charge the system back using 1000PSI hydrostatic test pump and R134a high side coupler.

That seems to be the issue. I wouldn’t be suprised if the cylinder needs to be replaced. I am at 140k miles and am probably on the rough side of drivers, I’ll look into that, ever heard of where I can purchase one? Probably just through the dealership I’d imagine right?

 

[coltondesmond01]

The part the clinks when someone is rocking your rig, are you able to put your hand on it and giggle it yourself without outside influence?

I haven’t been able to do that. Seems like the car has to be rocking, and it’s a super loud clink. Sounds like your hitting a hammer on an anvil?

 

[coltondesmond01]

Are you lifted? Age, mileage, lift and driving style (i.e. off roading) could definitely wear out the KDSS piston itself, but you may also have some weird interference with the KDSS geometry due to the lift. It's possible for the sway bar to shift sideways within the mounts/bushings and then it can contact some part of the frame and/or skid plate when it moves around with suspension motion.

Also, FWIW last spring I was certain I had a clunk coming from KDSS and it turned out to be bad lower control arm bushings so check those if you haven't already.

I am lifted 3”. I do a lot of off reading and don’t baby it haha. So it would make sense that the piston would be bad. I have Treaty Oak off-road KDSS spacers as well. I have checked that I clear the frame and the skid plate even when the car is rocking and clinking.

I’ll check my lower control arm bushings too, I am fairly certain is isn’t that because I can have my hand on the piston and feel exactly where it clunks now. I just hadn’t heard of anyone needing to replace the KdSS piston/ram thing so figured I’d ask around. I am probably just going to bring it into a dealership and have them see if this diagnosis is correct and have them do it if it isn’t too expensive. If it’s $1000 or more I’ll have to consider some other routes like a KDSS delete or something, I’d rather not though because I love the on-road benefits it gives me.

Thanks for all the information everyone! I’ll be sure to let you guys know what I figure out!

 

[jfogz5]

I am lifted 3”. I do a lot of off reading and don’t baby it haha. So it would make sense that the piston would be bad. I have Treaty Oak off-road KDSS spacers as well. I have checked that I clear the frame and the skid plate even when the car is rocking and clinking.

I’ll check my lower control arm bushings too, I am fairly certain is isn’t that because I can have my hand on the piston and feel exactly where it clunks now. I just hadn’t heard of anyone needing to replace the KdSS piston/ram thing so figured I’d ask around. I am probably just going to bring it into a dealership and have them see if this diagnosis is correct and have them do it if it isn’t too expensive. If it’s $1000 or more I’ll have to consider some other routes like a KDSS delete or something, I’d rather not though because I love the on-road benefits it gives me.

Thanks for all the information everyone! I’ll be sure to let you guys know what I figure out!

Curious what the end result was? Any update? What resolved the clunk?

 

[jonshonda]

Just an FYI for anyone with noisy KDSS. I replaced all the bushings front and rear for the KDSS system and it rides much better now. This is on a 17 w/ 55k miles. Remember those KDSS bars are freaking huge so the bushings have a lot to deal with.

 

[r2m]

I haven’t been able to do that. Seems like the car has to be rocking, and it’s a super loud clink. Sounds like your hitting a hammer on an anvil?

That type of sound, sounds like something that is caught on something else and then when forces from the other side impact it, it releases with that hammer sound. I wonder if it's something that catches and resets after it hits?