Hi All,

Wondering if anyone has info on frequency that rear diff & transmission fluids need to be changed. Not driving the cars much these days so Maint Minder isn't much help. Is there a suggested mileage frequency or time frequency that the fluids need to be changed? I know with oil, with low mileage driving, need to change it at 12 mos even if not driving it much. Thank you,

 

I have a 2017 RDX that I purchased used with 41k miles. I just had my RDX serviced last week at 64k miles (service code A123). I believe the previous owner had it serviced somewhere around 30k miles. I'm guessing every 30k miles is safe. If time is a concern, I would go with every 2 years. It's fairly easy to do if you want to DIY.

Good Luck.

 

This is from a Russian service book that someone else provided on this site, (credit to them, can't remember their name) but it looks like every 30k miles (45k kilometers) or 36 months.

I would honestly do a full transmission fluid change every 15k seeing how fast the transmissions cook the fluid in this car, but that's just me. Based on my ownership experience so far, every 30k miles is too long of a time.

Use OEM Honda DW-1 trans fluid. For the diff, you can buy Valvoline full synthetic 75w-90 gear oil. It is nearly the same spec OEM and you will be fine using it. It even comes in a handy 1qt pouch, which allows you to insert the head easily into the fill hole without much pain.

Don't bother going to a dealer for this - they likely will only have it in the giant drum and not be able to sell it, or the will charge you ~$40 usd for a quart. The parts guy at my local dealer actually talked me out of buying it because the valvoline is basically the same stuff. I think it was less than10 bucks vs 40 for the Honda branded stuff. Normally I'm big on OEM stuff but it's just gear oil, it's not that hard to screw up.

 

AUGH I have to come back here to correct some misinformation from nearly 2 years ago!!! In the previous post above, I mixed up the diff fluid and the transfer case fluid...

In the 13-18 RDX, the TRANSFER CASE FLUID is any 75w-90 gear oil, and for the REAR DIFFERENTIAL the fluid is the Honda or Acura OEM Dual Pump II fluid.

Better correcting it late than never I suppose. I feel terrible for the fake news

I just did the rear diff job again here at roughly a 40k mile interval. The dual pump II fluid new is clearish pink, and the fluid that came out of the diff was more a maroon-ish red. The magnetic drain plug had about the same amount of metal material as a transmission drain plug, nothing too crazy.

For anyone else stumbling upon this, you need a low profile 3/8 socket + torque wrench, 36 ft/lbs for both drain plugs. Also need a hand fluid transfer pump.

It takes 1.6 quarts of Dual Pump II fluid for it to fill the diff and weep out the fill hole. Lastly, you need a 18mm and a 20mm crush washer for both the fill and drain plugs.

 

Have you ever monitored the transmission fluid temperature using a diagnostic tool? Or is that what you heard on forums?

After reading some of the concerns about that on this forum, I did and during stop and go city driving as well as highway driving, the ATF fluid temperatures were nothing to worry about. Sorry, I do not have or can remember the numbers since they were of no concern, otherwise I would have noted them.

By the way, my final drive took 1.3 liters (1.37 US qt) of lube and the two aluminum sealing rings are: 90471-PX4-000 (18 mm) & 94109-20000 (20 mm).

 

I have the same numbers. After Honda began installing an additional transmission fluid cooler, it stopped being hot as before.

 

Do you remember what year they started installing those coolers?

What I need to do is run that test again on a hot day to see how much the ATF temperatures change.

 

Ridgeline since 2006, Pilot and TL since 2009, RDX since 2013.

 

Nope, I think I just have PTSD from my 3G TL + multiple Odysseys in our family with that issue. The original post I made a few years ago may have been before I did a decent amount of trans maintenance on the RDX (full fluid change, filter change, pressure switch replacements, and the trans software update), because since then it has NOT been "cooking fluid" like other Hondas + Acuras I regularly drive.