peugeot 206 automatic gear breakdown

good day 2001 model lpg li peugeot 206 1,4 xr bva automatic gear car i bought the car 4 years ago there was a light knock on the gearbox so it was nearly 4 years I did not scroll back on the hill or the traction was good but for 2.3 months the knock of the vehicle increased from behind the car is like hitting, it is more knocked down at low speed, it is like there is a gap in gear when you press the throttle in the gears. But when I hit the knob and press the gas, there is a gap in the gear, and there is a forward throw, sometimes it is hard to downshift. I went to the mug about a month ago. n will be affordable

Those who know will write, but as far as I know, the problem disappears after changing 2 cellonoid valves and transmission oil.