Found it easy the last time, that's the thing, Don!
First two here were probably ten years apart. Remember looking awhile the first time and finally touching the bridge while just generally touching everything trying to find the noise. One of the "eureka" moments when the noise went away.
Second time I remember far more vividly. Was a long way from home and began to hear engine noises. Wasn't sure what it was but it didn't sound good. In one of those "well, might as well ride it until it drops" modes as it was on a long holiday weekend, nothing was open and had 800 miles to get home. At a gas stop didn't immediately find anything. Then after what had been a couple hours highway riding it dawned on. Reached down and burned my finger on the rear bridge and, voila, no more noise. Finger didn't hurt at all
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