Have a 2005 Accord with 53K miles.

Never had the transmission fluid changed. The owners' manual recommends replacing the transmission fluid every 120K miles or 6 years.

The car hasn't completed the mileage but it has been 8 yrs now. Is there any harm in changing the fluid now?

 

No harm.

Many folks replace their ATF at intervals much less than Honda recommendations; 3yrs/30k miles for instance.

good luck

 

The folks at Pennzoil 10 Minute oil change places would probably say your ATF needed changing even if you changed it last week. Ditto the battery.

 

And I wouldn't trust them to do it either. I seriously doubt they'll put Honda fluid in there and if they choose a non-Honda fluid I doubt it's one that's actually good.

Anyway to OP: I say go for it. You're not replacing the full amount anyway. Depending on the trans you'll probably only get a 1/2 to a 1/3rd out so it's not like it's going to "shock" the transmission. I think 53k is a great time to do it.

I actually do mine in shorter intervals. I think 120k is BS way too long. I'd wait no longer than 30kand since you're 53k I would definitely do it. It's easier than an oil change. Make sure you use Honda ATF fluid, if non-Honda I would look for reviews to make sure people have used it and there's some history of people being satisfied with the other fluid but I strongly recommend Honda fluid. It's what $6.50 a quart for DW-1? Maybe some non-Honda ATF might actually be better than DW-1 but the important part is you can't go wrong with the Honda fluid and I wouldn't want to take chances when it comes to an AT.

 

The owner's manual says that

To thoroughly flush the transmission, the technician should drain and refill it with Honda ATF-Z1 (Automatic Transmission Fluid), then drive the vehicle for a short distance. Do this three times. Then drain and refill the transmission a final time.

Do you think the service departments do the drain and refill 3 times, as suggested by the manual?

 

The Owner's Manual says to drain, drive, and refill, three times? Yikes, I've never seen that section of my Owner's Manual, I wonder how I missed it.

 

It's likely the owner's manual just says do it once and depends on what year also. In Honda-speak, a trans "flush" is multiple drain/fill cycles.

I think it's better to just do one drain/fill at a sufficient interval that the ATF doesn't get real dirty in the first place. This 3x cycles is more for dealing with a trans that has been allowed to get real dirty.