Wilkinson 4+1 Breaking Strings

[PickerMike]

I put a Wilkinson 4+1 conversion kit on my 1980 Fender Precision bass several years ago, and had no problems for several years. Now, after replacing strings, the D string breaks during tuning. Anyone using this conversion kit have similar problems? Any ideas?

[charlie monroe]

Did you change brand/model of strings?
Check your bridge for a burr.

Maybe you need some nut sauce...

[PickerMike]

Probably changed brands and/gauge...couldn't remember and didn't save packaging. Have since tried several single strings with no luck. No visible burrs. Thinking of using a slightly smaller diameter string so it will require less tension. Am I thinking of this correctly?

[PickerMike]

I applied a touch of WD40 at points of contact and movement. String is breaking at a point where it goes over a small roller. Roller appears to be moving freely when it has no tension on it.

[tbplayer59]

Where did it break? At the tuner? The bridge? The nut?

[PickerMike]

The string breaks at the bridge. The bridge has a knurled knob, threaded tuner on it for the extra string (the D). The string passes through the knob, which has a washer in it to prevent string twisting (it seems to be moving freely with no tension on it), then over a small roller. As the string is tightened, the point of contact (at the bridge) is the roller (the string is bent slightly at the roller). As the force against the roller increases the string fails at that point, just before reaching the proper pitch. I can send some photos, but I was hoping that someone would be familiar with this conversion bridge and maybe had the same problem.

[tbplayer59]

What brand string are these? There was a recent thread about new strings breaking. The only ones I've ever had break were DRs. Years ago.