[JapsFinest]

Hello All-

I know that this has been discussed many times. No real answer in any of the 15+ threads on the subject. Hopefully this thread will lead to find the reason that this is happening...

The clunking started shortly after the install of my Billstein 5100's with stock springs on the third height perch(2.75"). I have checked the usual suspects such as the sway bars and end links to ensure thy are torqued down properly. I even greased the rubber bushing that holds the sway bar to the frame. I still have the clunking sound. I had a mechanic look at it and could not identify the source of the noise.

I can replicate the noise very easily by taking load off the front suspension and rapidly loading it back up. From a dead stop, I rapidly accelerate to 13-15 mph loading the rear suspension and letting the front end come up, once the front end is peaking before it has a chance to naturally level out, I press the brake pedal at 50-60% creating a nose dive. I will get a clunk clicking sound as soon as the weight shifts to the front and the truck is diving- then as soon as I release the brake pedal from the nose dive and the weight comes back off the front suspension I will get a second clunk and click.

I started thinking about the design of the 5100 shock with the adjustable spring perch and wonder if this could be the reason that many of us have experienced the noisy 5100's. I am wondering if the softer stock springs are loading and rebounding and moving the perch off of the adjustable snap ring for a split second. When this happens the perch is creating the noise as it slams back in place.

Please chime in with your experience on this particular setup and if you have been able to resolve it, how you did it.

Thanks!

 

[UTEFJ]

No experience with the 5100's, so I am just throwing some ideas out there.

Possibly bad strut mounts/bushings.

Also, I had a clunk during compression/front end dive that turned out to be the sway bar and the lower cover/skid plate making contact. I only found it when I removed the cover when doing some maintenance and noticed the rubbing on the sway bar. Note - I have the swaybar relocation brackets for the Sway-Aways.

Just a few thoughts. Probably not either of these, but worth looking at.

Good luck.

 

[FJtest]

I think you may be premature in blaming your new Bilsteins for yourr "clunk". There are many other potential noise sources that you need to eliminate one-by-one before you definitively say that the struts are the root cause.

Here is just a basic question: did you install the specific strut part number recommend by Bilstein? What year is your FJ, and what Blistein P/N did you buy?

 

[JapsFinest]

I think you may be premature in blaming your new Bilsteins for yourr "clunk". There are many other potential noise sources that you need to eliminate one-by-one before you definitively say that the struts are the root cause.

Here is just a basic question: did you install the specific strut part number recommend by Bilstein? What year is your FJ, and what Blistein P/N did you buy?

FJtest, I am not balming bilstein for my clunk. I am trying to identify why so many people have noise issues when using this setup. I dont see many theads of guys with OME, FOX, Marlin, TC, Toytec, or others complaining of the noises that the guys w/5100's complain about. There is a common factor and the poll will help to sort out if its user error or design. I am not leaning towards either. I would love to have a setup that does not make any noise.

Now, the part number for my front struts is BIL-24-186711 purchased from 4wheel parts in ORlando , FL. As soon as you posted the question, I knew there was always the potential of someone being lazy and selling me what they had in stock and not what I actully needed. I checked on the bilstein site and found the catalog link below and learned that yes I have the correct part number.

http://www.bilsteinus.com/fileadmin/user_upload/user_upload_us/pdfs/offroad-catalog-2011.pdf

So what else would cause this noise?

 

[FJtest]

(snip)
Now, the part number for my front struts is BIL-24-186711 purchased from 4wheel parts in ORlando , FL. As soon as you posted the question, I knew there was always the potential of someone being lazy and selling me what they had in stock and not what I actully needed. I checked on the bilstein site and found the catalog link below and learned that yes I have the correct part number.

http://www.bilsteinus.com/fileadmin/user_upload/user_upload_us/pdfs/offroad-catalog-2011.pdf

So what else would cause this noise?

You never confirmed your FJ's model year, but based on the Bilstein strut P/N you selected it's an '07-'09, correct?

The very first place I'd look would be the very last thing you touched before the clunk appeared, e.g. the struts.

Who installed the springs on your struts? Make sure that the lower spring seats weren't inadvertantly installed upside down (very easy to do).

Double-check torque on all strut-mounting fasteners, top and bottom.

Did you replace the strut mounts themselves?

Next, focus on other likely sources for "clunks", which almost always are caused by clearance that allows relative motion and impact between two parts.

How many miles are on the FJ? Did you check for any wear in ball joints, wheel bearings and tie-rod ends? Sometimes installing new, stiff struts will load other suspension components differently than the worn struts did, and will emphasize noises that were not previously audible. Worn sway bar bushings can also generate clunks.

Are all the other front suspension components the original parts? No aftermarket upper or lower control arms, no front sway bar disconnects, no aftermarket front axles, original front springs, etc.? Were any skid plates removed during the strut install?

And, you've checked the inner fender steetmetal for any signs of the cracking problem that's common with the '07-'09 FJ's?

 

[WaJohnZ]

^^^^ Exactly... Who installed the new Shocks, are the control arms original stock or replaced with aftermarket.
Jack up the front wheels so they are in the air a few inches then take a long bar 3-4 feet or a 2x4 of similar length and place under the tire, use the bar to lever up and down against the tire. Does this replicate the sound ??? This should not be some great unsolved mystery, something is worn, loose or contacting something.

 

[Maximus]

Could be the control arms! Upper or lower.. I have 5100 with OME 885 springs and I hear a clunk every now and again

 

[iwashmycar]

No way in heck the springs are letting the perch lift up...they would break if that happened. Snap ring would shear right off. Happened to me on a smaller scale on my rear Bilstein shocks that have tiny snap rings...I had a bushing on wrong which did allow a tiny bit of movement.

Do you have the perches on the right way!?? Seems like a common mistake...they need to go down OVER the snap ring like a mushroom cap or something.

I am leaning towards your LCA bushings potentially making noise. Brake pads can do it too, though that is mainly a problem out back, not up front. Make sure the pad retaining springs are still there in place!

I have a small noise very similar to when yours makes noise, but it is more of a pop sound. It is my aftermarket skids.

 

[JapsFinest]

• Yes it is an '07.
• 40K miles.
• suspension is all stock except for the 5100's.
• Using the stock springs.
• I re-used the stock hat
• ball joints are all in great condition
• End links are torqued down
• control arms are stock
• alignment has a good amount of caster
• I did not check the wheel bearings directly but there is zero play
• sway bar is torqued down to end links and frame
• perch is on as per the instructions provided by Bilstein

The only thing left to verify from the suggestions above would be the nut on the top hat. I did not rush through the process and believe it to be correct but this is the only piece that I have not re-torqued again in search of the noise.

The drivers side clearance between the spring and UCA is close when the suspension is at full extension with the wheels off the ground however no contact. In full compression, there is no contact. The noise comes from both sides ut is more prevalent in the passanger side. My initial thought was focused on the sway bar since the sound is coming from both sides. I have gone over the sway bar several times...

 

[JapsFinest]

...Jack up the front wheels so they are in the air a few inches then take a long bar 3-4 feet or a 2x4 of similar length and place under the tire, use the bar to lever up and down against the tire. Does this replicate the sound ??? This should not be some great unsolved mystery, something is worn, loose or contacting something.

In order to replicate the sound it takes an aggressive nose dive. I Put the front end on jack stands and tried to replicate it by jacking up the suspension by the LCA and could not get the compression quick enough to create sound. I doubt that I will be able to leverage a poll to replicate it but thanks for te suggestion

 

[WaJohnZ]

Only during a hard nose dive or ..Braking???
One possibility is who ever did the alignment did not tighten the lower control arm adjuster cam enough. The force from braking or hitting a bump moves the lower control arm at the pivot point and actually makes a loud clunk and not always or every time.

 

[FinnJ]

I guess the upper mounting (shock nut/bushes) is not tighten or mounted correctly.

 

[mach1dsg]

I have 5100's specific for my year model, (there are two versions, one for the 07-09 FJ's, and another for 2010-2013 FJ's) with the Toytec 112-620 springs, zero clunks from the setup, and I have around 40k miles with it, initially I started with stock springs and 4tn notch, never had any clunks, then 3k miles later I bought and had the 112-620 springs installed, zero clunks no matter how bad I've abused them.

 

[KF5WZU]

Something in my driver front started to clunk last week. Suspect the suspension or brakes, but wiggled everything and it all seemed bolted down tight. Happens in the mornings as I roll down the driveway (driving forwards), and sometimes when starting from a full stop. Checked the sway bar clearance, and it's extremely close to but not touching the springs. Will update if I find the cause.