The owner's manual says to replace the ATF fluid at 120K miles under normal conditions and 60K miles under severe conditions. Since I usually drive in between both conditions, I usually do my servicing in the middle of both mileages. So, I thought about just waiting until 90K miles to do the service, but since I drive in 115+ degrees several days and 100+ several weeks out of a year, I thought I'd just do the change at 60K.

When I went to the Honda dealer, the service manager said he has two levels of ATF service. The first, for $79, is just a drain and fill. The service manual states it takes 3.4L of ATF to do this service, but takes 7.8L of ATF for a full overhaul. So, with the drain and fill, you're replacing only 44% of the ATF fluid.

The second level of ATF service is a full flush and fill, which costs $179. Most of the fluid should be changed out, but not quite 100%.

Either service, Honda doesn't recommend any type of cleaners or chemicals. So no matter which you choose, make sure the mechanic doesn't pour anything else into the transmission.

$100 more wasn't worth the extra cost for me, especially since I'm really not near the actual change interval. So I decided it was best for me to do the $79 drain and fill this time at 60K, and then when 120K comes around, do the full $179 service then. When it comes time to do your own ATF service, weigh your options and make an educated decision on what you want to do to your car.

I should also note, draining and refilling your ATF fluid isn't really that hard. I opted for the dealer to do it because I was already there for an issue related to my Odyssey. There are techniques some people use in which they drain/fill, drive for a bit to get the fluid mixed around, drain/fill again, drive some more, and drain/fill one last time. After constant diluting of new fluid and old fluid, the end product is something like 90% fresh fluid. And all it costs you is several bottles of ATF fluid and your time. But it saves you lots of money.

So anyways, back to the story. If you want to check your ATF fluid level (something you should be doing on a semi regular basis), make sure your car is warmed up. Park the car on level ground. Within 90 seconds of turning off the engine, pull out the yellow handle dipstick that's in the driver's side front of the engine, wipe it with a clean cloth, stick it back in, pull it out, and check the fluid level. There are two holes in the dipstick. The fluid should fall between those two holes. If it's low, use a funnel and pour Honda ATF-Z1 fluid into the dipstick hole until the level is between both holes.

If you want to drain and fill yourself, with a warm transmission, remove the drain bolt at the bottom of the transmission to drain. Be sure to replace the drain bolt! I hear of some people that forget and their new ATF fluid ends up on the floor. Reinstall the drain bolt with a new washer and torque the bolt down to 36 lb-ft.

As always, I offer suggestions and a bit of hands on knowledge of tasks I've performed myself on my own car. This information should be used as a guideline and not as instruction. Always be safe when performing your own maintenance. And, what has worked for me, may or may not work for you. Your mileage may vary...

 

Actually Honda does not recommend full flush for their transmissions. Only drain and refill is recommended (three times if ATF is dirty). Check your service book it is written right there.

 

The service manual (actual Honda one) doesn't specify with kind of flush to get. It just gives the procedure for the drain and fill. But it goes on to say if you're installing a used/rebuilt transmission, to perform a full flush using (I dont' remember what they call it) a Honda branded transmission flush fluid. If anyone really wants to know what that fluid is, I can look it up when I get home. The reason, as it states in the service manual, why they recommend a full flush at that point is because there could be unknown contaminants in the old fluid.

 

All late Accord/Odyssey transmissions have internal filter accessible only after whole transmission is taken apart. That is why they do not recommend do flush using Wynn's equipment and such. Because all worn debris lying still in the bottom will be pushed toward this filter and clog it causing all sort of problems associated with low ATF pressure in all lines. This is good to know and we have to refuse all offers of full flush using machines.
As one said on OdyClub forum: "A flush machine that allows the trans to pump the fluid should not be damaging, but one that forces fluid is."
Unfortunately Honda's 5sd automatic transmissions are not great for service life.

 

I've looked everywhere for good info on replacing the transmission filter, but can't find any. I have the filter and have now done the 2nd drain & fill--I assume the filter should be changed after draining, so now it's time!

Anyone? I'm on 225xxx miles and this is the first tranny service I've done. . . Thanks!

 

There is no accessible filter in transmission. You have to take transmission apart in order to change the filter.