Knocking noise when braking

[Chrismendoza10]

I’ve got a 2018 jlu rubicon (10800 miles) with the Rm 2.5” flex lift. However the mrs drove the Jeep the other day and it noticed some knocking noise. I’ve crawled under the Jeep and don’t see any grease or fluid leaks. Today I put Jeep in reverse and noticed the knocking noise when I push the brakes on the Jeep when going forward. You’ll are definitely more knowledgeable than me so I’m hoping you all could point me in the right direction in regards to getting this fixed. I took a video from under the Jeep, albeit not the best and can’t seem to upload. Appreciate any help

 

[duktrx]

Check your caliper bracket mounting bolts.

 

[WJCO]

I'd recommend checking anything related to the lift. Likely a loose bolt. Check shocks, sway bar links, track bar, etc.

 

[kevman65]

Who installed the lift and how long ago was it installed?

Could be anything contained in the lift, or anything loosened and removed to do the lift.

Check every single nut and bolt for tightness.

That's just the start. If you don't find it there, start looking at any bolt or nut in the steering package, or bolted to the axle.

 

[duktrx]

Can you post the video to YouTube, then link it here? The collective brain trust can probably narrow it down quickly.

Thinking outside of the box here, does it have drop brackets for the brake lines? If so maybe they are slapping the frame rail when the brakes are applied.

 

[Chrismendoza10]

The lift was installed about 4 1/2 years ago and Jeep has most likely been driven about 3k miles in that time frame.

Didn’t go with the drop brackets for the lift.I will try and see how to post to YouTube and then link it. Not the best video and all I was doing was reversing and then going forward a couple of feet in my driveway. Also if brake hard seems like I Can fell the steering wheel move a bit.

 

[Chrismendoza10]

Hope this link works and with admins permission

 

[kevman65]

Rotation in the front axle, you can see the drive shaft jump when the "CLUNK" happens.

Check all the bolts on the upper and lower control arms. Also check all the bushings in the control arms. 4 1/2 years old something could be worn out.

 

[Bear_JT]

Nicely ask the Mrs if she “bumped” or ran over anything. I can see that driveshaft movement also. I’d look at the front brake calipers also.

 

[duktrx]

Rotation in the front axle, you can see the drive shaft jump when the "CLUNK" happens.

Check all the bolts on the upper and lower control arms. Also check all the bushings in the control arms. 4 1/2 years old something could be worn out.

Based on how the axle is rotating, I agree look at the control arms.

 

[Chrismendoza10]

Nicely ask the Mrs if she “bumped” or ran over anything. I can see that driveshaft movement also. I’d look at the front brake calipers also.

I’ll need to be very careful …

 

[Chrismendoza10]

Also another question, should I be able to rotate the front drive shaft by hand when the vehicle is parked ???

 

[JimLee]

Also another question, should I be able to rotate the front drive shaft by hand when the vehicle is parked ???

Yes. Check all your control arms for tightness. I had a driver side rear upper control arm bolt loose that sounded like it was the on the front passenger side.

 

[jeeeep]

along with checking control arms, check the bolts on the drive shaft; my jku had a similar clunk and found the bolts of the stock DS were loose.