these torq converters when they fail or come apart internally they will ruin the transmission
it really sounds like a failing torque converter
Many people describe this feeling as running over a rough spot in the road. Very often the problem is a torque converter shudder. A torque converter shudder is a brief shake or shudder in the vehicle when internal clutches apply inside the torque converter. They refer to this application of clutches as "lock-up." Often this problem is mis-diagnosed and sometimes they needlessly rebuild transmissions as a result.
A quick test
On many vehicles, one way to identify a torque converter shudder is lightly touching the brake pedal. While carefully maintaining vehicle speed with one foot, delicately apply the brakes with the other. If the shudder immediately stops, with brake application, the problem is likely the torque converter clutch. When the operating system sees brake application, most vehicles release the torque converter clutches. A trained transmission-service technician can also test for torque converter lockup using a specific vehicle scan tool. These tests are important as a slight engine misfire very often causes the same sensation and is may be mistaken for a torque converter shudder.
How a torque converter lockup works
The torque converter is a coupling between the engine and transmission of the vehicle. The purpose is to allow the vehicle to come to a stop, with the engine running. To do this something has to slip, and that is the torque converter. From this perspective, it acts much like an automatic clutch.