Transmission issues or something else

I have the truck listed above with a 7.5 inch Lift, and thirty five inch mud tires. Yesterday I was at a friends, as I went to back out of his freshly graveled driveway, I
placed my truck into reverse, The indicator was showing it was in reverse,
and I felt the transmission shift, However, as I started backing up, it
sounded like an old party whistle as indicated in the image below. I tossed
the truck into neutral rather quick, allowed the noise to stop, then placed it
into park again. After a few seconds and me scratching my head, I tried it
again. This time there were no issues what so ever. It shifted normally,
and I was able to back right out, I was rather easy on the acceleration
backing out since that issues had just took place, I did not want to risk
causing any more damage to whatever happened. Occasionally I will get a
loud clunk and a extremely hard jerk as I put it into reverse and start to
accelerate, almost as if the front end or the transmission wants to drop out
completely. What on earth could be going wrong with my transmission? I know
those lift kits are hard on parts, but to cause my transmission to do all this?