2000xj 4wd 4.0 automatic with 196k miles

so, slightly bigger tires, hit bumps tires grind, going to pull small boat, so added a leaf. After this process, I now get a loud noise when accelerating between 55 and 60 mph only. Going that speed and not touching the gas, no sound. So, I assume I screwed something up.

Ifeas as of what to check it do I need to take it somewhere. It took a long time in the driveway, so I don't want to completely go back through it. Bolts seem tight. Is it that or is the differential dipped down, something else?

thanks

 

Ujoints? The added height may have altered them.

 

See if you can wiggle your slip yoke if so then you need SYE also check your axle to trans angle make sure they are square with one another.. Thats similar to what I have going on..