Im having the same issue. I just bought a 2016 Accord touring it has 80k on it. I did a transmission fluid service a couple weeks ago but only once. He said there was metal shavings in it. Probably was never done it still vibrates when I'm holding steady on the gas. Usually around the 35 up mark. Had it checked and all the joints and axls were good. I balanced the tires too. I have no clue what's going on.

 

I do not believe it is possible to "check" an axle to be sure it is not causing vibration. Think about it, many lower quality brand new axles cause vibration, the DuraLast axles from AutoZone I put on my TL last year are a prime example. The OEM axles "felt" solid after 133,000 miles when I took them off (but they were causing vibrations), the brand new DuraLast axles sure as hell "felt" solid when I put them on (vibrations were reduced but far from eliminated). I put a new set of APWI axles on this year; the "felt" just as solid as both previous sets, but these completely eliminated all vibrations.

 

Update on my transmission issue,

The transmission didn't provide any codes when the service department checked it last week and tires and wheels were checked to determine if there was an issue with them. All came back balanced and straight.

My plan is to have the transmission fluid replaced at the next engine oil change which should be in January or February.

 

I had my fluid changed and it helped a bit. Thinking about doing it again 2 more times to really flush it out