Differential Noises at speeds of 45-55

Need input please,
I seem to be having diff. noise at speeds of 45-55. I find no noise below or above those speeds. I've changed the diff. oil, greased the u-joints and had the truck lifted onto jack stands and put into drive to check the carrier bearing. No noise there. I really hear it when up against a retainer wall or freeway K-rail. I also hear a jingle of some sort but there is nothing loose underneath. I've put the rear end up on jack stands and had the wife put it in drive and listened to the diff with a tattle tail tool at high speed but not at those speeds as I felt it to be unsafe. I only hear normal sounds of the gears turning. I am stumped. It is an e-locker so I am wondering if that component is starting to wear. It works fine when on the ground. I have been warned not to engage the e-locker without resistance so I did not engage while in the air. If anybody has experienced anything close to this please advise.

I will be making a cross country trek pulling a car and tow dolly in about 6 months so that's my window to resolve.

2000 Tacoma 2wd Prerunner all terrain tires 3.4l v-6 106.K miles
Never Off road