Front End Clunk - 2018 Off Road

We had the skid plates removed to replace the R&P, and didn't put them back on before taking it for a test drive to eliminate that as an option.

We also tried disconnecting the sway bar yesterday when trying to narrow down the clunk's origin. Wasn't that.

I moved alongside the vehicle when driving it forwards and backwards trying to pinpoint the sound and it might be coming from the upper right of the front LH wheel well. Nothing up there seems loose though.

Will keep the KDSS front piston in mind!

 

That's what i'm wondering too. It must be a bolt shifting when the vehicle flexes from movement. Which bolt? TBD.

You'd think you'd be able to see which bolt is moving because of the rust - the shifting should keep scraping the rust off. Must be concealed behind something if that's the issue.

 

Take the diff drop off, I bet it goes away. You need the diff drop if you have lifted the truck for better angles but I suspect it’s that

 

The clunk in the video in post #18 sounds very much like something is binding up, then letting go, which seems to be the noise. I can't imagine what that could be, however. Were you successful setting up a go pro to try and pinpoint the source?

 

just going back to basics, because I experienced this while off roading only. I would hear a clunk, turns out it was my recently installed recovery points and the shackles were banging.

 

I recently removed and regreased my UCAs in 3 different areas prior a trip and that seemed to do the trick!

hopefully you are able to resolve this issue soon

 

You got yourself a proper mystery! Some more thoughts in the spirit of trouble shooting…

I know you said that you replaced the SPC control arm once to make sure it wasn’t the problem….but, it does seem like people tend to have really bad luck, repeatedly, with SPC UCAs. Something in their design seems to lead to problems. I guess what I’m saying is that you’re probably reduced the likelyhood it’s the UCAs, but maybe not outright eliminated the possibility you got another bad pair. If you end up looking at them again, maybe replace them with UCA’s that have ball joints similar to stock. Or just throw stock UCAs as a troubleshooting step, then replace them later if you want to get your alignment dialed in.

The only other thing I’d suspect (and this is a pure guess given my ignorance of repairing frames) is maybe there was a change in frame geometry after you cut out and rewelded in new crossmembers. Which ones were cut out? Maybe the heat of welding just pulled things in too tight, enough to cause binding somewhere, like a control mount tabs?

How about the possibility of bad bushings on the lower eye of the shock? Or maybe something related to the lift height (and spacer)?

 

Body mount bolt secure, especially on the wrecked side?
Crash bar tightened down behind plastic cover?
Anything dangling behind or around headlights?
Airbox and filter mounted secure?

 

Also, inspect this area around the zirks and where the shaft connects. There is flexing everytime it goes in/out of reverse. A little crack is all you need for this thing to give you problems.

 

Went to upload the video taken, but when we hooked the camera up to the computer it had to format the SD card and deleted it So, going to have to try to catch it again.

 

Thanks for the idea! My shackles are solid so this unfortunately isn't the clunk i'm searching for. I appreciate the suggestion though!

 

Thanks for the brainstorming! You're right that it could be a bad set of SPC UCAs - we haven't ruled that out.

I've wondered about the geometry after all the adjustments that were made post accident. Someone previously mentioned the shock tower could be slightly off causing a clunk which would fall into this out of whack geometry theory (and the possible bolt clunk). There really isn't anything left in the front end to replace, so geometry seems like the last logical potential source for the clunk.

So, i'd like to inspect the entire shock setup.

 

I've been checking every bolt I run across just in case, but I will try giving each of these a turn.

Leaving no theories untested!

 

Will take a look, thanks! The sound is coming from the front end though so I suspect this won't be it.

 

Went back and re-watched/listened to your video...made me think about what I used to do in the labs when monitoring for unwanted movement between objects in contact with one another and how the folks that did my suspension check their work...it's called 'bolt torque indicator'. Permatex makes one called Bolt Mark Indicator (Tractor Supply has it). Use it on all bolted/fastener junctions and you could try striking a line using simple chalk at interfaces such as around the Knuckle, sway bar mounts/frame interfaces, Cam tabs/bolts, etc.

 

Thanks! We've tried a paint pen, but that stuff looks relatively affordable. Will pick some up next time i'm at Princess Auto.