Question on a issue with the tranny..I think. Have the 700r4 on an 89 Suburban 1500 w/ 350. 135k original miles. Couple days ago as I slowed down it sounded like two gears grabbed causing a loud noice and jerk feeling through the rig. At the next light I put it in neutral and slowed down and it did the same thing. I could hear what sounded like the wheel of fortune spinning and which slows down as Suburban slows. Then when the knocking or flapping sound stops the sound of gears grabbing starts - two times usually. No noticeable changes in shifting pattern. No issues from drive to reverse or neutral to any gear. Fluid is clean and full. Any ideas? First 700r4 owne.