Rumble when slowly accelerating

So about 3 weeks ago I did a tire rotation oil change and transmission drain/ fill measured out the fluid that came out and put the same back and did a bearing carrier drop for my 6 inch lift. I started having a small vibration when I slowly accelerate at around 3rd-4th gear it usually happens between 1,000-1,500 rpm’s it feels like I hit a rumble strip on the high way for like 1 second when it happens. It seemed to fix the problem for a little while but now it has came back. It doesn’t do it when I accelerate heavy. Truck is shifting gears fine has anyone else had this issue I’m seeing a lot about drive shaft joints and carrier bearing along with a possible torque converter issue.

 

I’ve done trans drain and refills that way before without any issues, but you need to make 100% positive that the temperature of the fluid you added was the EXACT same as the amount you took out. Also, make sure you are using the recommended fluid your vehicle calls for. My guess is that you either over or under filled your transmission fluid.

 

Truck was fine before you did the services, bearing drop? What kind of tires on your truck? My bet would be something in the area of the u joints/carrier bearing. Maybe the u joints had a wear pattern before you lowered the carrier and now they are pissed off/disturbed and making noise now? How many miles on the truck?