'96 Fly Classic: Threaded Rod for Trem Doesn't Move

[Yames]

Hi All, - I've had my '96 Maroon (Cherry?) Fly Classic for quite awhile. After a string change from .9s to .11s, the bridge tilted strongly toward the neck. I have an .11 spring installed, but turning the tension wheel didn't bring the bridge back to level. Upon disassembly, the issue is the black plastic sleeve (with the spline) inside the hole near the strap pin that the threaded rod fits into. It looks to me like this "spline sleeve" should be stationary with the spline fitting into the groove in the threaded rod, to keep the rod from rotating when you turn the adjustment wheel. The plastic spline sleeve rotates freely in its hole by the strap pin, so when I turn the wheel the entire sleeve and threaded rod rotate. The threads on the wheel can't push the rod toward the bridge to compress the tension spring with the "T"-bar.

I can turn the spline sleeve in its hole with my pinky and it doesn't feel like it was ever "anchored", but I think it must have been for the system to work.

Have you guys seen this before? I searched the topics on this excellent forum but didn't find anything similar. I haven't pulled the black sleeve out of its hole because I don't want to damage the clear silicon(?) anti-friction thingy. I thought I'd ask for advice before I take things apart and try to concoct a fix that may do more harm than good.

Am I correct that this sleeve was originally stationary? Does anyone know how it was anchored so it wouldn't spin? The trem worked great before the string change so I think the sleeve did its job prior to this.

Any thoughts or suggestions you may offer are welcome. I've blocked the trem so I can play the guitar, but I'd love to get it working again.
Thank you in advance for any ideas, - Yames

[vjmanzo]

Hi Yames—sorry to hear this. The part is indeed anchor editing, but I believe it’s only press-fit into place. I’ve not seen this issue personally. You are correct that the part should not rotate freely.

when I turn the wheel the entire sleeve and threaded rod rotate.

Does the wheel spin smoothly on the rod from one end to another? Does it need oil? It’s possible that a burr or other “catch” point on the rod causes the wheel to jam and then, as a result, cause stress on the part in the cavity that is now rotating freely.

As long as the part is inserted properly and still has a notch, I don’t see any reason why it couldn’t be glued back in place—we can verify with @Ken Parker whether the parts are, in fact, glued in.

[Yames]

VJ - Thank you so much for the reply. Fortunately, the threaded rod and the wheel are in pretty good shape, but they could certainly use a cleaning and lube. I figure I'll start by refurbishing the rod and wheel, then check for any binding or catching. My go-to adhesive for glueing the sleeve would be Plumber's Goop by Eclectic Products. It holds very well and if it fails, any glue remnants can be completely removed without solvents (it kind of balls up like rubber cement). As a first stab at a fix I think it will be reversible if it doesn't work, so I'll give it a shot.

Thank you for your helpful advice, I'll let you know how it turns out.

[vjmanzo]

Happy to help! Yes, that seems like a great approach—please keep us posted!

[Yames]

I'm cogitating on fixing the trem vs leaving it blocked for the time being. I'm a casual trem user, but after looking at Fly Rod's pics of the consequences of a broken spring, I've come to understand that failure of the Fly's trem spring could be more serious than I thought. 120+ pounds of compressional spring force 1/2" away from top wood 1/4" thick is making me a bit squeamish. This is such a great playing guitar, I would be crushed if it got damaged. I'm tempted to leave the trem blocked for awhile and do the repair if I find myself missing it.

I made a trem block by whittling on a scrap piece of stout plastic I had in the garage (from a car part?). On one end I cut a slot to accommodate the "T" bar. On the bridge end I put two pins to prevent the block from shifting inward and contacting the top should it decide to move. The plastic piece is mostly hollow, very strong and light, and seems to be doing the job so far. Please excuse the "Notes to Self", that's so I know what it is and how it goes if it spends a long time in the case.

Thank you again for your help. If I work up the gumption to tear out the silicone anti-friction ring that's preventing the removal of the spline sleeve and proceed with the glue, I'll post how it comes out. - Yames

[Yames]

Thank you VJ for your advice. I glued the black plastic "spline sleeve" into it's hole by the strap pin so it doesn't rotate. The threaded rod now moves when the adjustment wheel is turned, compressing the spring to balance the trem as it should. I used E6000 glue from Eclectic Products, which bonds very well to both plastic and wood and is easy to clean up.

Re-reading the manual, I can see that I never had the spring fully compressed to the "Fixed" setting as it suggests for tuning etc. The guitar has always held tuning and the trem worked very well with more slack in the spring than the manual recommends. The bridge is nearly flat (veerry slight tilt toward the neck) with this lower spring force, so I'm going to keep it that way for now (I have .11 to .52 strings with an .11 spring). I figure the likelihood of spring fatigue and failure will be lower with lower spring force, and with the trem set to "Balanced" it works just fine.

Lastly, after reading up on lubricating aluminum to aluminum threads (between the rod and adjustment wheel) I went with Vaseline, which is basically thick, pure mineral oil. Lithium-based wheel bearing lubes may react with aluminum, silicone based lubes may dissolve the silicone friction ring the adjustment wheel turns against, and lighter oils may evaporate or soak into the wood. Vaseline should stay put and is easy to remove with mineral spirits, so we'll see how it holds up.

Thank you again for your advice, my favorite Fly Classic is back to full functionality!

[vjmanzo]

Yeah, @Yames! This is great news!!

#VibratoBridge

[Yames]

Just for completeness, I'd like to add a few details in case somebody else has to tackle this issue.

In order to remove the black plastic spline sleeve so I could glue it back in, I had to cut away the inner 1/16" of the silicone anti-friction ring that surrounds the hole the threaded rod slides into. In the picture above labelled "Spline facing bass side", the inner portion of the silicone ring looks "frilly". This is because it stretched as I tried and failed to pull the spline sleeve out of its hole (the sleeve is larger than the hole in the silicone ring). Rather than peel the silicone ring off the guitar, I took a pointy X-acto knife, slipped it into the small gap between the outside of the sleeve and the wood guitar body and cut the inner 1/16" of the silicone ring away so the spline sleeve could be removed.

To apply the glue, I put a 1/4" blob on the end of a short 1/8" dowel and smeared it around the inside of the hole in a couple of passes, checking with a flashlight for full coverage. Then I jammed the black plastic spline sleeve into the hole.

Upon reassembly, the threaded rod wouldn't slide far enough into its hole to make a gap bigger than the length of the spring, so I couldn't install it. Inspection with a flashlight revealed a blob of glue on the inside of the spline sleeve that was stopping the threaded rod from reaching full insertion. E6000 adhesive holds very well, but it is easily cut, so more microsurgery with the X-acto knife got the blob of glue out of the hole, and now everything works!

Thanks for indulging me, another Fly player may find my maunderings useful.