Rep Power: 0

Have a 2009 civic EX 120K miles. I have done the 3 quart change twice in 60K miles, just 3Q out 3Q in ( not the repeat 3 times method ). When under low load going from first to second it feels like a "chatter". I really only feel it at this time under little load. If there is and load it shifts through the gears perfectly. Downshifts as expected when going downhill with foot off gas. Any suggestions or input ? Could it just need the 9 quart transmission fluid change or bring it to a dealer ( ugh ), and have them do a flush and fill ? Current fluid doesn't smell burnt and looks pretty clean...

 
Rep Power: 518

Sounds like you described Torque converter shudder.
The cheapest thing you can try is the fluid (Hondas DW-1), several drain and fills (simple DIY, 3x3 or 3x4). Sometimes it helps a lot, sometimes it does not.

If that doesn't solve the issue, it would need the torque converter replaced.

 
Rep Power: 142

Consider changing the transmission filter as well, fairly involved job but the filter is cheap. See my post on this.

 
Rep Power: 0

Thanks All !! I tried the first three quart change over and the chatter improved significantly. Going to do two more cycles of the three quart change and see those results. How important do you think changing the filter is on a scale of 1-10 where 1 is most important. Seems to be getting mixed reviews on the forum. And I certainly don't have tiny arms and hands, mechanically no problem if I can see the filter...

 
Rep Power: 518

At this dealer we don't replace the filter with any routine trans service. An owner would have to ask for it specifically to be replaced, and would be charged accordingly.