Transmission started making clunking/jerking noises, loud whining, rattling, and eventually slight pulsations/hesitation. Took it to AAMCO Transmissions and they confirmed that the transmission had suffered internal failure, and would need to be replaced entirely.

Update from Sep 28, 2021: Took it to a different repair shop for a second opinion, and the technician said that this generation of Civics, only Civics, had a flawed design with the spring pressing the clutch plates together. Over time, this spring would wear out, and have difficulty engaging each gear's respective clutch. Reducing the amount of gear shifts/using cruise control might help reduce the wear on the spring. It seems this entire generation is plagued with this design, so I would avoid the 8th gen (2006-2011) altogether.

Update from Jul 7, 2023: Doing multiple "drain and fills" of the automatic transmission fluid using Honda genuine ATF DW-1 resolved the issues I was having before. The aforementioned symptoms continued and became progressively worse, so I did some Googling and other people were having very similar issues, with changing the fluid being the ultimate solution. There was also some misdiagnosis done on this issue:

1. Whining noise - from accessories area in the engine compartment. Noise went away after removing belt; issue is likely a drive belt tensioner. 2. Clunking/jerking - almost completely resolved after performing two drain and fills (~50 miles apart). Issue was likely dirty/worn fluid moving around the transmission in a turbulent manner, causing intermittent clacking/clunking noises when accelerating and decelerating, as well as shifting between gears. 3. Hesitation - almost completely resolved after the first drain and fill. Before, when accelerating, there was a delay when the engine would rev up and the vehicle to "catch" and start really moving. This was the worn-out fluid not applying steady pressure to operate the partial lockup clutch in the torque converter. This can also lead to delayed shifting.

For context, my transmission was serviced by the dealership once in 2010 at ~30k miles (likely using the older Z1 fluid). It was never serviced until just now at ~180k miles. The fluid appeared dark red and smelled slightly burnt when I changed it. If your fluid's completely black and smells horrendous, I would advise against changing it as it can lead to slipping and other issues after. Also, the first time draining the transmission fluid, the drain plug may be very very tight; you might have to use a breaker bar. Lastly, make sure you only use Honda genuine ATF DW-1; other brands may cause shifting issues. I purchased 3 quarts and a drain bolt crush washer at the dealership for around $35.

I wish I could remove my old post. Honda makes great vehicles, and the 8th generation is no exception!

All I can say is I'm shocked... I have owned many Honda Civics and have NEVER had a transmission fail, let alone with under 115K... yup, that's me always bragging up Honda reliability and being loyal to the make, and now am eating those words... yah a peeling clear coat is one thing, however the total transmission failure has me shaking my head; and has unfortunately, and sadly undermined faith and now possible loyalty to the brand... Looking at about $1,500 for the repair, having to dig DEEP for this one, after all the main reason I have continued to purchase Civics was to avoid this very problem!

First the block cracked on this car at 76000 miles and the engine had to be replaced. But, at least Honda covered the repair. Now, the transmission has a complete failure (put the car in reverse it goes one foot and the wheels lock) to the tune of $4300.00. These were easy miles on this car...light traffic to and from work mostly between 45 and 55. I have maintained the car well and changed the trans fluid when recommended.

Despite many reported complaints about the transmission for this year and prior years, Honda does not want to help with the repair costs. I probably will not buy another Honda. When did this car company start building cars like Detroit back in the 70's?