So today someone else drove my truck and when they were pulling in they backed it in and the rear axle to bed jumped when they shifted. I can now hear a grinding noise while driving coming from the read diff. Wondering if anyone knows what this maybe since I have a few guesses but want to be sure.

Side note the left rear drum brakes were replaced since one of the pads cracked but it still squeaks like crazy and it sounds like the parking cable is always engaged since I can hear a stretchy spring noise when driving in lower gears.

Thanks for any help.
99 dodge ram 1500 5.2liter automatic 123k miles

 

Jack up the rear, but the trans in neutral, and spin things by hand. See if anything feels 'off'. If it does, pull the cover, and have a look, shake the driveshaft where it hits the rear diff, and see if the pinion bearings are still tight.