Tightening that Dynamic Vibrato tremolo arm

A common question of new owners of guitars with a Dynamic Vibrato is how to keep the tremolo arm in the tailpiece bar. The tremolo/bridge unit of the Fender jag-stang and most mustangs is a Dynamic Vibrato, so this article applies to both the jag-stang and mustang.

The first thing to know is that the tremolo bar itself does not “snap” or screw into place like the tremolo bar of a stratocaster. The tremolo bar is held in place by pressure from a small allen screw in the tailpiece bar.

The photo below points to the location of this allen screw. Note the location indicated by the blue arrow pointing into the end of the tailpiece bar.

dynamic vibrato tremolo screw

So to hold your tremolo bar in place get the bar in a position you are comfortable with and then snug the screw in the end of the tailpiece using a 4mm (or 5/32″) allen wrench. Don’t over tighten this screw. (see below)

dynamic vibrato tremolo screw

So another very common problem is that the screw in the end of the tailpiece bar will be missing. They fall out very easily.

There are not a lot of options for finding a replacement screw. You may have to buy an entire dynamic vibrato tailpiece that includes the screw. Or another option would be to pull the tailpiece bar off the guitar and take it into your local hardware store looking for a screw that will fit.

[If anyone has found an exact replacement for this screw please let us know the details and we’ll add it to this article.]

23 thoughts on “Tightening that Dynamic Vibrato tremolo arm

  1. As an owner of a Mustang that had that screw fall out, I would welcome information on it.
    I haven’t found anything myself yet.


  2. Be warned that there are two major differences between the old vintage Mustang tailpieces and those on the reissue Mustangs and Jag-Stangs. The old tailpieces are made with SAE (American) measurements and threads, and the new ones are metric. You can’t use the set screw from a new tailpiece on and old one, and vice versa, without stripping the threads.

    Also, the old tailpiece had a plastic insert in the set screw hole to keep the screw from marring the tremolo bar, and the new ones do not, and this is really bad. When I bought my Jag-Stang, I installed the tremolo bar and tightened the set screw so the bar would stay in one position. Not thinking anything of it, I moved the bar around just like I would on a Strat. When I removed the bar I found that the set screw had cut deep grooves into the bar, essentially ruining it. Leave it to Fender to take a bad tremolo and make it worse.

    The solution is to make a piece of plastic like what was used on the old tailpiece. You’ll need to cut a small pill-like cylinder of plastic that will fit in the set screw hole but large enough where it will fit without falling out. That way the bar will be held in by pressure on the set screw but will be cushioned by the plastic insert.

    Incidentally, I found a great way for left-handers to block off Mustang/Jag-Stang tremolo. You need to find a right-handed Mustang tailpiece and remove the pivot bar. Find two short bolts with the same thread as the pivot bolts. Flip the righty bar around and bolt it into your lefty tailpiece plate with the short bolts and mount to your guitar. The end result is a tailpiece pivot bar mounted rigidly to the tailpiece plate with proper holes in the back for mounting the strings. The strings follow through to the front and will go over the bridge at a lower angle, thus holding the strings tighter on the bridge, helping your intonation. The best part is that this is a completely reversible modification.

  3. Mine’s a 77 made in USA Mustang.
    But it never had the plastic piece you speak of–the bar has a flat spot cut into it where the screw goes–and it worked great.
    The screw came out when I took the handle off and put the screw back in -it worked itself loose at some point after that and I don’t know where or when.

  4. i have a fiesta red jagstang, one thing i did for my screw on the bottom of my vibrato is bought a jar of anti seize and put some on the set screw. it makes the set screw keep from vibrating out as well. i also filed a groove into my bar so that it hangs loose(that works for me)

  5. I have a 65 mustang and I too am looking for that screw…no one knows what size will fit yet?

  6. The originals use just a common set screw allen or slot type and can be gotten at any hardware store. What I do when I get a Mustang for repair is to use a concaved set screw and a steel ball from a bearing. I insert the bar and mark the shaft, remove and cut a tapered groove on the shaft. When the ball is inserted in the hole, it will align up the groove in the shaft and when the set screw is tightened down, it will still allow the whammy bar to move but it will not tear up the shaft. You need to add a little grease in the hole first.

  7. Can anybody else confirm that the 8mm screws are the right ones to fit the hole ? thanx

  8. The 8mm screws will fit, but you could get those at home depot just ask for metric head hex screws.
    The package says :

    Set Screw Socket
    5mm x 8mm
    Plain Steel

    I got two for 60 cents.

  9. Regarding the plastic insert. Before finding this, I didn’t know about it, but I knew that the arm on my ’64 could be rotated and stayed in place, and the arm on the trem I bought from Warmoth would either be loose or too tight to rotate. I removed the screw, and cut a small “chip” out of a rubber faucet washer. I pushed the rubber chip into the screw hole, and replaced the screw. It works just like the plastic insert described above.

  10. My son has a jagstang that was partially disassembled and we are trying to get it back together. I think the tailpiece is on correctly from reading the above comments. The bridge is complete but I think there might be some bushings missing since it fits very loosely into the holes. Are ther supposed to be bushings in the holes? Looks like setting the intonation would be impossible without something to take up the slop.

  11. :::STAN FLAHAUT:::

    I bought my Jagstang at a pawn shop and worried for a long time that it was incomplete or had second-hand parts. Turned out to be all original but even then I wasn’t sure if my setup was correct. These videos helped me get a good visual idea of how it’s supposed to piece together.

    http://www.youtube.com/watch?v=3-w02DtCsCk (parts 1 and 2)

    As far as I can tell the bridge is supposed to fit loosely so it kinda rocks back and forth. It been working good for me. You could also replace it with a totally different bridge as well (I believe Cobain did).


    Anyone know what kind of tremolo bar to use with the vibrato? All I can seem to find are the threaded kind.

  12. Does anyone have problems with the height of the tremelo bar when it is all the way in? I just got a mustang and the tremelo bar is to high off the strings.

    Also I was wondering if anyone had schematics on how to tighten up the springs in the vibrato system.


  13. 76 mustang owner.
    i bought this guitar from og owner..lookes like a flat head screw to tighten, and the bar is really high off strings im very confused..

  14. I have an old mustang…frm my dad..which i found in my garage..lol….im always scared that…the whole tail piece would fall off…cuz its all rustedd…idk..is it supossed to..look like its about to come off?

  15. For those who asked – the older Mustangs use a screw with a 10-32 thread – same as a standard rack screw. I haven’t found the exact screw for my 1966 Mustang yet, it needs to be a very short screw with a head that isn’t bigger than the threads, so it can recess in to the hole. I’m using a rack screw for now!

  16. On a general note I will often use Plasticine or Blu-Tac to twist in and out of a hole like that if I need to know the thread and diameter, It takes a mold of the thread and I can take the measurements. Worth greasing the hole first just to help the Plasticine/Blu-Tac screw out.

  17. The set screw for the trem bar, on my vintage mustangs, is 6×32, very easy to find at any hardware store, that has those little drawers of odd fasteners .. they cost about .30 cents . I don’t know what the metric size would be..

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