Here's my 3yr + story chasing front end suspension "clunk":
In my case, the clunk first appeared after installing the first set of FRPP lower arms in 2015 due to worn factory originals. I bought the parts and the dealership provided the labor. As soon as I pulled out the parking lot it made a "popping" noise from the passenger side when making right turns. I immediately took it back. The tech confirmed what I was hearing and put it back on the lift and said he made some adjustments and it was quieter but not perfect. I went ahead drove it for a few weeks and it became progressively more noticeable. I took it back a few more times and finally gave up for a few months.
It finally got bad enough that it would "pop" while turning the wheel lock to lock while parked. I finally took it to different dealership and that tech said it was the sway bar links and bushings. So I had those replaced. Seemed "ok" for a few weeks and then started "popping" again. Took it back to him and he crawled under and had me turn the wheel lock to lock. He said I must have gotten a defective FRPP arm in the box cause he could feel the "popping" coming from the ball joint. So I ordered another FRPP set and only replaced the passenger side and I made sure to keep the old/newish arm. Again all was seemed good for a few weeks then it came back. At this point I just gave up again cause I was tired of spending money and had used enough unpaid time off. In November of 2015, now having access to a friend's garage I decided to replace everything short of what had already been replaced (LCA's, sway bar bushings, and links) on the front suspension. I replaced inner & outer tie rods, struts and strut mounts (FRPP). I even made sure that the K-member nuts were torqued down.That damn popping was still there. I then just gave up for well over a year.
Then earlier this year I decided to go ahead replace the sway bar bushings with poly and went ahead and replaced the links with MOOGs instead of the FoMoCo parts. No bueno. Then just a few weeks ago I took it in to get the alignment checked at Pep Boys. The tech came back and told me that the forward (small)bushing was worn out on the passenger LCA. He had me come out in to bay and told me to watch as he took a pry bar to the bushing and the arm moved a good 1/2" back and forth on the pivot. I then gave him a brief history of what I had been dealing with for the past few years. So, on a hunch, I put that first FRPP arm back on and as I stated previously, I also decided to get new bolts while I was at it. Popping is now gone! Suspension is totally quiet!
I have taken it down some of the bumpiest roads around and over speed bumps and not a even a creek.
Also, see my pics of the worn lower control arm bolts in the same thread: https://www.allfordmustangs.com/foru...me-nuts-7.html
So far I still have zero clunks since this past Christmas.
2006 GT- Airaid Race CAI, 62mm BBK TB, SR Performance UD Pullies, FRPP Hot Rod Cams, CMDP's, Excedy Stage One Clutch and lightweight flywheel, Pacesetter Long Tube Headers with matching O/R H-Pipe & MBRP Street Axlebacks, Lito 91 Octane Tune