'15 T4R KDSS w/ KING shocks clunk

[borfoo3]

2015 4Runner KDSS at 71,500 km (~44,500 miles)

Lent the truck to my brother for some time and it came back with a mystery clunk on the front driver side. Sound became more frequent over time but I still can't replicate it 100%

Seems to happen when I turn and start moving, also at some speed bumps and most frequently on hard braking. I can 'feel' the clunk on the steering wheel when it happens too.

JBA UCA's are ~6 months old with few offroad trips, KING shocks are under a year old.. No clunks after any of this was installed. Did all 4 brake pads + SS hoses last month

Lifted the truck to check LCA bushings, seemed ok. Didn't feel anything loose..


You can hear it clearly at exactly 3:01 on the video

<iframe width="560" height="315" src="https://www.youtube.com/embed/QwU7dgyAH2U" frameborder="0" allowfullscreen></iframe>

 

[4Running303]

Sounds like the KDSS clunk. mine does it most consistently on trails, coming down and around switchbacks.

 

[jbjones85]

Any chance the coil is leaking? I had a similar noise with my icon and it was because it was leaking fluid.

 

[honda250xtitan]

i'll trade ya shocks and get rid of that clunk for you. 6112's straight for your clunky kings

at 3:01 when you hear it, the suspension isn't really even cycling. it's not a hub starting to go out is it? bolts are all torqued on the coilover? Did you check the spherical bearing on the lower shock eyelet?

 

[jrandom]

Well having a thunk in my kdss is usually from the lca kdss bushing, my goes away it I hit it with some lube. Easy fix if that is the case. Most lifted trucks the kdss lca bushing is no longer nicely resting in the bushing cup.

 

[borfoo3]

i'll trade ya shocks and get rid of that clunk for you. 6112's straight for your clunky kings

at 3:01 when you hear it, the suspension isn't really even cycling. it's not a hub starting to go out is it? bolts are all torqued on the coilover? Did you check the spherical bearing on the lower shock eyelet?

Lol I'll keep the clunky KINGs.. coming from a 6112 myself, I can tell you its actually better than it looks performance wise!

Will check those bolts once more. Repeating the vid for the 10th time I'm also thinking sticky brakes or a bad brake job..

Any chance the coil is leaking? I had a similar noise with my icon and it was because it was leaking fluid.

Didn't see any leaks :/

Well having a thunk in my kdss is usually from the lca kdss bushing, my goes away it I hit it with some lube. Easy fix if that is the case. Most lifted trucks the kdss lca bushing is no longer nicely resting in the bushing cup.

Yes they do have an awkward angle to them. What do you grease them with?

 

[jrandom]

Yes they do have an awkward angle to them. What do you grease them with?

Anything light, you don’t want to attract dirt/sand. If have tried a few things they all seem to last about the same, Gunk Dry Lube Teflon based, WD 40, blaster penetrating lube.

I think if some talented engineer type spent an hour or two they could design an aftermarket cup to account for the change in the LCA angle, they would make mint. Heck throw a grease zirc on it too

 

[Gabex35]

I had this same clunk and it went away after a recent rebuild. Shop recommended replacing the lower shock mount spherical bearing as they are not an item that lasts too long on Kings.

haven't had an issue since. Good Luck.

 

[ayeyothisiskyle]

I get the same sound sometimes, difference is its only when backing up and turning (backing out from a parking space or driveway). One of my friends said it was the UCA. I have the same JBAs pre-cerakote ball joints. They are a tiny bit rusty but I hit them with WD40, and they are quiet for awhile. I know the ball joints are greased because I overgreased them. I too can't really replicate it on demand but its there. I might have to decrease my preload on the kings and check to see if that does anything.

I know its not a solution, but I just wanted to add my 2 cents because we have such similar setups.

 

[borfoo3]

I had this same clunk and it went away after a recent rebuild. Shop recommended replacing the lower shock mount spherical bearing as they are not an item that lasts too long on Kings.

haven't had an issue since. Good Luck.

How long did it last before rebuild?

I get the same sound sometimes, difference is its only when backing up and turning (backing out from a parking space or driveway). One of my friends said it was the UCA. I have the same JBAs pre-cerakote ball joints. They are a tiny bit rusty but I hit them with WD40, and they are quiet for awhile. I know the ball joints are greased because I overgreased them. I too can't really replicate it on demand but its there. I might have to decrease my preload on the kings and check to see if that does anything.

I know its not a solution, but I just wanted to add my 2 cents because we have such similar setups.

Where does the UCA rust? on the arm itself or close to the joints/ bushings/ bolts?

I also over-grease the UCA BJ, and got almost zero pre-load on the KINGs but with higher than default coil rates.

I did experiment on the side of a steep ramp last night.. I can now replicate the clunk consistently with lateral load on the tire (i.e. when it 'pushes' on the side of the ramp before climbing it, then again after releasing brake tension from top)

Still not sure I've narrowed it down lol.. but its not coilover related at least

 

[ayeyothisiskyle]

Where does the UCA rust? on the arm itself or close to the joints/ bushings/ bolts?

I also over-grease the UCA BJ, and got almost zero pre-load on the KINGs but with higher than default coil rates.

I did experiment on the side of a steep ramp last night.. I can now replicate the clunk consistently with lateral load on the tire (i.e. when it 'pushes' on the side of the ramp before climbing it, then again after releasing brake tension from top)

Still not sure I've narrowed it down lol.. but its not coilover related at least

Yeah, I dont think its coilover related so I think its the UCA or KDSS bushings. My balljoint is slightly rusty, but JBA said to just order the cerakoted ball joints and request a return label. Once you they get your ball joints, they will refund the cost of the cerakoted ball joints. I'm going to order the new cerakoted BJs and lower my preload to see if that helps.

I might not be understanding how you're replicating the sound. Is only one corner of the truck on the ramp and youre getting the clunk when you initially roll up the ramp then when you release the brake at the top of it?

 

[borfoo3]

Yeah, I dont think its coilover related so I think its the UCA or KDSS bushings. My balljoint is slightly rusty, but JBA said to just order the cerakoted ball joints and request a return label. Once you they get your ball joints, they will refund the cost of the cerakoted ball joints. I'm going to order the new cerakoted BJs and lower my preload to see if that helps.

I might not be understanding how you're replicating the sound. Is only one corner of the truck on the ramp and youre getting the clunk when you initially roll up the ramp then when you release the brake at the top of it?

Yes exactly. The ramp is flat going down on the side (like a high curb) where I'm approaching it at an angle and testing each corner at a time. Kinda like this one but wider and without rails:

 

[borfoo3]

UPDATE -- SOLVED!

So we went through everything once more (cleaned/ tifgtened/ tested) and figured out it was the LCA bushings gone bad. The rear one was in worse shape and that cam bolt had some of the threads damaged too which was a pain to remove. Bought 4 new bushings, 1 cam bolt and did both sides as it made sense to freshen everything up.

Once it all bolted back on (KDSS sway bar was a REAL pain) no more clunks and she drives nice and smooth! Case closed.

Pics for ya:

 

[nb rob]

Thanks for the follow up. It’s a great resource with the video you posted.
Glad you got it figured out!

It was my impression that the accepted procedure for replacing the LCA bushings was to just replace the LCA assembly.... I guess I just assumed the bushings themselves were hard to find...?
Was it easy to remove and replace the bushings?

 

[borfoo3]

Thanks for the follow up. It’s a great resource with the video you posted.
Glad you got it figured out!

It was my impression that the accepted procedure for replacing the LCA bushings was to just replace the LCA assembly.... I guess I just assumed the bushings themselves were hard to find...?
Was it easy to remove and replace the bushings?

I was too. Fortunately that's not true.

Turns out the bushings and cam bolts are not KDSS model specific parts. They actually fit all recent 4Runner and FJ models alike so pretty easy to find.

The bushing itself is a complete unit that can be hammered out of the LCA as you see above. It takes a few tries and you will ruin the old ones in the process of removing them. The new one just slides in with an easy tap.

Not hard at all. Each bushing cost me around $50 so that's $200 for all 4 plus $10 for the new cam bolt. The LCA itself was solid so no need to waste money changing it just for bad bushings.

 

[nb rob]

Awesome. I did some poking around after I posted that, and I had no problem finding them for close to $50 as well. Thank you for the information.

:cheers:

 

[mrblah]

I was too. Fortunately that's not true.

Turns out the bushings and cam bolts are not KDSS model specific parts. They actually fit all recent 4Runner and FJ models alike so pretty easy to find.

The bushing itself is a complete unit that can be hammered out of the LCA as you see above. It takes a few tries and you will ruin the old ones in the process of removing them. The new one just slides in with an easy tap.

Not hard at all. Each bushing cost me around $50 so that's $200 for all 4 plus $10 for the new cam bolt. The LCA itself was solid so no need to waste money changing it just for bad bushings.

How did you figure out it was the bushings when you inspected it on the vehicle or did you rule out everything else first??

Im getting a inconsistent thud when I go over speedbumps or pot holes. I've ruled out alignment, CV Joint, steering rack, bump stops, and UCA. So that leaves me LCA and the Kings Lower shock mount.

When I inspect everything for play, everything has no play, although I think visually the lower shock mount is shifting....and that would make sense if I"m getting inconsistent thunks going over big bumps or holes at speed.

Anyways, I'm not sure how to inspect those parts while its on the vehicle.

thanks

 

[borfoo3]

How did you figure out it was the bushings when you inspected it on the vehicle or did you rule out everything else first??

Im getting a inconsistent thud when I go over speedbumps or pot holes. I've ruled out alignment, CV Joint, steering rack, bump stops, and UCA. So that leaves me LCA and the Kings Lower shock mount.

When I inspect everything for play, everything has no play, although I think visually the lower shock mount is shifting....and that would make sense if I"m getting inconsistent thunks going over big bumps or holes at speed.

Anyways, I'm not sure how to inspect those parts while its on the vehicle.

thanks

I went through the same process first. Then took it to a friend's shop and did a quick test on both sides as follows:

Found an open area and did a couple go-stop runs with a spotter looking at the suspension and LCA. He stands driver side and I turn left, press hard on gas then hard brake several times while he checks. Then did the other side.

He noticed the driver side LCA was moving back and forth horizontally along with a clunk. Good bushings should be holding it solid and only allow for up/down movement (for suspension travel)

The bad bushings we're allowing the LCA to move excessively in a horizontal motion which results in the clunk as metal contacts or binds

Although only my driver side was bad, I did both LCAs just so I don't have to open the other side later on

Hope this helps.

 

[tral]

OP - so are you saying that you were able to push out the OEM bushings on the OEM LCA without melting it out?

I ask because Toyota parts told us that the OEM LCA'a were not serviceable hence the "*" in the parts catalog. I was told I had to order a whole new LCA ($400)!!!

Glad you found the issue.

 

[borfoo3]

OP - so are you saying that you were able to push out the OEM bushings on the OEM LCA without melting it out?

I ask because Toyota parts told us that the OEM LCA'a were not serviceable hence the "*" in the parts catalog. I was told I had to order a whole new LCA ($400)!!!

Glad you found the issue.

Exactly.

You don't need a new LCA if its only the bushings.. I'm sure Toyota would rather you buy the whole thing