Honda ATF Type 3.1 when prompted by the Maintenance Minder (should be around every 60,000 miles).

If driven regularly under specific, severe conditions, change every 30,000 miles.

 

30000 if you are going to keep it.
Rock Auto now have 3.1 fluid and its the cheapest I have found

 

Are there any writeups or videos concerning the DIY procedure on a 2020 RL?

 

Here is the writeup for the 9 speed transmission.

 

Hi, could someone assist and post part numbers for the 3 drain/refill bolts for the 9 speed transmission; 2021 ridgeline? One site says it is the same 20mm bolt & crushwasher as for the rear differential; but other research suggests it is a bolt that has a green "seal" built into the bolt and you don't use a crush washer? And I understand if I follow the PDF instructions in the previous post, I'd need two of the bolts; the 3rd built in the top of the engine doesn't need to be removed or used?

Also just confirming, I should use part #08200-9017 Honda ATF 3.1, 3.5 qts for a drain and fill (and not the DW-1, that is for the 6 speed?).

And for future reference when I'm trying to find the VSA/traction control maintenance mode setting, here are the instructions: ROC VSA maintenance mode

Thanks much!

 

....I plan to keep my 2022 RTL-E (I’m 75) indefinitely and our other vehicle is our primary vehicle. What are current thoughts on 9-sp transmission care? Fluids and frequency?

Honda ATF Type 3.1 when prompted by the Maintenance Minder (should be around every 60,000 miles).
If driven regularly under specific, severe conditions, change every 30,000 miles.

Here is the writeup for the 9 speed transmission.

@Harvey Wall post above has Honda service doc on this. It requires Honda Diagnostic System (HDS) to enter "VSA maintenance mode" - of course, we DIY owners don't have that. I always DIY all my fluid changes (except brakes), since I've had too many bungled jobs when others do it (over and under fills, stripped and/or over/under torqued threads, oil cap or fill plug left off, etc.). So what to do?

I'll probably DIY drain/fill my 2022 9-spd ATF at 30K miles, then have dealer do it at ~60K miles Maintenance Minder prompt (so it's documented in case of any future warranty issue). There are YouTube DIY videos on this. Most are simple drain, measure ATF quantity drained, refill with same amount (some videos are pretty sloppy...). I found the video below on changing the MDX 9sp ATF, where he takes a more thoughtful approach (mimics Honda's AT gear cycling, measures AT temp, ensures vehicle level, also looks also how Jeep did theirs with dipstick, compares quantity drained to Honda's spec. etc.). Seems to be well thought out (and having a ScanGauge to measure ATF temp should make this easier). Anyway, FWIW, proceed at your own risk (though that appears to be small).

 

I think I'd let the truck sit at least a day, with the bottles of new ATF in the vicinity of the truck. This is essentially trying to get old and new fluid to the same temp. Then replace with same volume.

Alternatively, one could drain the fluid, let it cool to same ambient temp as new bottled fluid, then replace with same volume.

I wonder if weight might be a more equivalent measure for comparison. In baking recipes, for example, weight of ingredient is preferred measurement to volume of ingredient (although the vast majority of recipes still stick to volume measurements), since volume readily changes with many items based on temp, compaction, etc.

 

The part that bothers me about this method is that it does not ensure that the level is correct - it only ensures that the level is the same as it was.

 

Yep, agreed - it could have been over/under filled at factory or by last ATF change. The Honda service doc says after ATF change the the fluid level as to be 6mm (0.25") higher than bottom of check hole, and the YouTube video in my post #7 puts it a little higher than that (for the reasons he mentions). So in both cases, regardless of how much drained, its level is trued up in those checks. It irks me that 9spd was designed without a dip stick, and the fill level is above the bottom check hole (a mess to check...). My other irk with ZF is the dog clutch 5>4 paddle downshift feeling. However, I find the ZF 9 speed to be pleasant to drive, effective for towing, I like its paddle shift options, and its reported reliability and durability is excellent (so I'll live with those two irks)