PFP backed out on Marz 48

[3beejay3]

On Sunday, the PFP backed out all on its own on my left fork during a ride. It actually backed out farther than it's supposed to be able to & ended up allowing a buch of oil to escape.

Has this ever happened to anyone else? Any ideas what caused it? If so how do we address it? (it's currently at my service guy)
(I did a couple searches, but couldn't find anthing, though I though I read on here a while back where someone else had this happen)

 

[3beejay3]

Found the problem-

Snap ring on the PFP adjuster broke out of its groove somehow. At the same time the spring for the compression adjuster detent ball popped out into the cavity and got all mangled.

Have no idea how or why this happened. Forks were just serviced with fresh oil, but nothing was dissassembled in this part of the PFP.....Any ideas?

Attached pic shows pieces that sheared off side of snap ring groove (orange arrow)

Originally I thought the pfp had backed out on its threads, but it was out past the orings. We had to use a vice grips to wind it back in trailside, but it actually tightened the PFP right up as stiff as it would go. This explains why my front suspension was 'off' during my ride on Sunday

 

[Jakobi]

Poor quality control.

How are the fine threads?

 

[3beejay3]

Poor quality control.

How are the fine threads?

The fine threads on the spring retainer cup and the mating threads in the top cap are pretty good except for a burr in one spot. I was able to get most of the burr removed- enough that it shouldn't cause any trouble. The two pieces mate fine with no sticking.

I brazed the snap ring groove with high strength aluminum repair rod, and it will get machined this wknd. We'll see how it works.
A new PFP top cap assembly is $500!

I'm surprised this broke they way it did as the forks have about 200hrs on them with no other problems so far.

The brazing looks a bit gumbied, but this rod is a bit touchy to work with, especially since the surface isn't flat. The stuff has proven to be quite strong when I've used it before.