Clunking noise over small bumps after bilstein shock install

ruggerag · March 4, 2019

I just installed bilstein 5100s on all four corners of my 2015 silverado 1500. I set the front shocks to the third notch (supposedly about 1.5" of lift), and I swapped the rear block with a new 2" block (1" more height). I got an alignment afterwards. Now I am getting some major clunking from the front end when I go over small bumps. Does anyone have any idea what is going on? It's not the bump stops, and I don't see anything else making contact, and it happens anywhere from very small to large bumps when I'm turning and going straight.

Thanks

FHLH · March 4, 2019

Mine has started doing this too, I believe it’s well documented here somewhere. I’m just taking mine back to the installer and having them fix it.

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cpttimerestraint · March 4, 2019

Switch the castle nut back to the OEM nut. Fixed mine.

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damnthetorpedoes · March 4, 2019

39 minutes ago, cpttimerestraint said:

Switch the castle nut back to the OEM nut. Fixed mine.

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This^^

I had the same issue when I put 4600's on my previous Yukon. Took it back to the installer and problem solved.

ruggerag · March 20, 2019

Which is the castle nut? The one on top, maintaining spring pressure? Or the ones on the bottom on the sides, mounting it to the lower arm?

I don't understand how this noise could be due to either. I spent a couple hours messing with it today, so I guess I'll try those next?

Darmichar · March 21, 2019

When I installed 5100's on my 2014 the nuts they provided didn't match the existing studs on the strut. I thought they got tight but there was about a 1/8"- 1/4" gap. Took them to the dealer and had them replaced and made everything nice and tight.

AJMBLAZER · March 21, 2019

Make sure the top nut is tight. I had to impact mine on again after initial install in order to actually seat them. 3 years and 60,000 miles since without the rattles.

TXGREEK · March 21, 2019

Same thing happened to me when I had Bilsteins installed, retightened and all was good

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ruggerag · March 21, 2019

This is the one nut that keeps the spring attached right? With the shaft passing through it, where you are supposed to use an adjustable wrench to keep it straight and tighten the nut with a crescent? How did you get an impact gun over the shaft? I tightened mine to have 2 full threads above it, I feel like I could tighten it for a long time with the spring compressed...

AJMBLAZER · March 21, 2019

Deep well impact sockets. All I own.

The pressure of the weight of the truck helps while tightening with the impact so you shouldn’T have to hold the shaft in place.

Conversely, when tightening with a torque wrench the pressure gets overwhelmed by your slow, gradual torque build up and lets the shaft spin So you need to hold the shaft in place with another wrench.

However the spring pushing up means you can hit the correct top nut torque before the actual compression required is reached. Had it happen on several different vehicles with similar strut setups. Impacting it on always fixed it without side effects.

ruggerag · March 21, 2019

Ok thanks guys. I spent five hours yesterday removing the shocks, changing the length/preload on the 5100s, and trying to install front blocks instead before deciding there was no way they fit, and giving up. So I am going to pull them back out, put them back on the 3rd ring setting, and then tightening the crap out of the top nut. Since I am going to pull the shocks anyway, and have to put them back on the spring compressor, how will I know when the nut is tight enough?

Thanks!

AJMBLAZER · March 21, 2019

Honestly I just tighten until the torque wrench clicks and then hit it with the impact a bit.

The impact version of “two grunts and a fart”.

More helpful - on my ‘11 if I bounced on the bumper I could see if the top nuts were loose. Impacted them on and checked until I couldn’t see the looseness.

Sierra Dan · March 21, 2019

Corrective action as stated above is to use factory top hat nut and retorque once the truck is back on it's own weight.

https://www.silveradosierra.com/suspension/bilstein-clunk-t649257.html

FHLH · March 21, 2019

Could someone with knowledge take a photo of the nut we are talking about?

Additionally, anyone have this gm part number handy?

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Sierra Dan · March 21, 2019

1 minute ago, FHLH said:

Could someone with knowledge take a photo of the nut we are talking about?

Additionally, anyone have this gm part number handy?

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See #10 in diagram