dkswim

Items needed
Oil pan
2.7 qt ATF-Z1 (Honda automatic transmision fluid)
3/8 drive ratchett and 6" extensions
gear oil pump
latex gloves



Procedure

1. park on level ground

2. remove filler plug and washer First. I'ts not fun discovering you can't open the fill plug after the oil has all drained out.
(Note you might need to use a breaker bar)

3. remove drain plug and washer. you can access both throught the subframe holes. you can also pull the plugs through the holes so if you have locking extensions like i do no need to worry about dropping them into the oil.




4. reinstall drain plug and new washer

5. add fluid till it starts overflowing the fill hole.

6. reinstall filler plug and new washer.

filler plug 47 N-m (4.8 kgf-m, 35 lbf-ft)
drain plug 47 N-m (4.8 kgf-m, 35 lbf-ft)

fluid capacity 2.67 US quarts, 2.23 imp quarts, 2.53 liters
recommended fluid: Honda ATF-Z1

there is no need to jack the car up it sits high enough you should be able to crawl under. Keep in ming the muffler might be hot. the best time to change is after driven so all the particulate are suspended in the oil. this service is to be preformed whenever maintnance minder indicates 6. Be sure to dispose of used oil in acordance with state and local guidlines.

k23a1

thanks! sticky please

fryrice

is the front diff the same?

InfamousJamous

This was easy! Note, you'll need a gear oil pump that reaches to the bottom of the quart. A hose can be used to extend the inside of the pump.

LSURidgeman

So the rear diff uses Honda ATF as well? I was looking in the owners manual for that but couldn't find it. That is sort of interesting to know that.

2005 Silver Bullet

Note that Honda is discontinuing ATF-Z1. Your local dealer is probably already out of stock. The replacement fluid is Acura All Wheel Drive Fluid (DPSF). It comes stock in 2011's and is backwards compatible to the older years.

Just did my 2011 (11.5K miles) last week. The rear diff. was stamped "ATF" but a clear/carmel colored fluid drained out (DPSF) instead of a cherry color (ATF-Z1). Found out that mine was a very late model build and Acura made a running change for the 2011's. I actually had ATF-Z1 on hand but needed to make a special trip to the dealer to get DPSF. Figured that whatever type of fluid came out should probably go back in.

Also, after draining and refilling, I ran it about 100-150 miles and then checked the fluid level again and it was a little low. No leaks, but it must take a bit of driving to get the fluid into all of the nooks and crannies. Topped it up again with about 3-4 ounces and put a new crush washer on. Everything drives great.

RDX guy

Stupid question - Which bolt is the filler plug and which is the drain?

I will be performing the rear diff. change this weekend for the 1st time, and was wondering if someone had a picture?

Thanks in advance.

RDX guy

Changed the rear diff. last weekend, and must admit it was a piece of cake. Nice write up, it is funny but when you are under the rear of the vehicle despite all the cutouts there are only 2 bolt (1 empty, 1 fill)

djbonsu

iTrader: (3)

Awesome info here! Just performed this on the wifes rdx this past weekend. Saved me a trip to the stealership!

LC2ner

What size washer do I need and how many of them??

RDX guy

18mm--------90471-PX4-000----- 20mm--------94109-20000--------

kimck99

Hi,

I just changed the differential fluid on my 2009 RDX and I thought I share my experience. Overall, it took longer than I expected. I want to say it took about 2 hours but I was also rotating my tires from front to back. (My tires have directional thread pattern so I can only go front to back.) Also, I had an issue with a lug nut nearly stripping the bolt screw using an impact wrench. So that took some time for me to fix.

Here is what I did.



Drain and Fill Screws

• Someone asked how do you know which is which. The second picture above is tilted 90 degrees counter clockwise. It threw me a bit but once you get under the car, you'll see that the lower screw is the drain (of course) and the top is the fill.
• I unscrewed the fill screw and then the drain screw
• I first tried using a 6 in socket extender through the frame as the original poster stated. I gave up as it was very tight and I couldn't get enough leverage to unscrew. So, I took off the 6 in extender and just used the socket wrench. There is enough space between the frame and the screw. This allowed me to apply more force to the socket without wiggling.
• After I unscrewed the FILL screw, I loosened the DRAIN screw. Then placed the oil drain pan underneath and then used the 6 in extender through the frame to remove the drain screw.
• Note, the drain screw has a magnetic tip which picks up any loose metal shavings in the differential pan. So, I didn't have a problem dropping the screw in the oil drain pan. There is enough metal around the pan and frame where the screw catches.
• When draining, I decided to lift the front of the car with the floor jack. This helped to get the fluid out. I didn't plan on doing it but since I was rotating my tires anyway, it was a bonus. Next time around, I would still lift the front end of the car to drain.

Filling the Fluid

• First, I purchased 3 quarts of Acura ATF-DW1 transmission fluid from local Acura dealer. They said that this was the replacement for the ATF-Z1.
• I placed the 3 quarts in a small box and then unscrewed one at a time and inserted the fluid pump. I would recommend you do something similar to help keep the bottle secured. Otherwise, if you just leave the bottle by itself, as you pump, you can accidentally knock it over.
• I first started the fill without jacking up rear of the car. Well, I'll never do that again. I installed an Eibach springs so my RDX is about 2 inches lower than stock. It was a tight squeeze to get under the car. After about 2.25 quarts, the fluid started to spill through the fill hole. I thought that wasn't right. It's suppose to take 2.67 quarts. I thought about it for a bit and made two changes.
  • I jacked up the rear of the car and placed two jack stands at the rear left points.
  • Inserted the fluid pump hose deeper into the fill hole.
• Pumping again, this time, it took about 2.8 quarts before spilling. I attribute the additional amount of fluid because I jacked up the rear.

Anyway, it took longer than I expected but next time it will go much faster having done it already.

I hope this information is useful.

Regards,

littleblazer

You don't want to put ATF-DW1 fluid in the SH-AWD .
ATF-DW1 is for transmission only.
Acura has All Wheel Drive Fluid (DPSF) for SH-AWD differential

kimck99

Hmm. This is a bit disconcerting. I asked for the DPSF fluid and they didn't have it. So, I told them that it was to replace the rear differential oil so when he punched that in his computer, it came up with the ATF-DW1 as the replacement.

Has anyone else checked with their local Acura dealer?

Now I'm wondering if I need to change the fluid again. However, in my limited mechnical knowledge, how much different is a transmission vs. the rear differential? They both are gears that move thus thinking that perhaps the same tranmission fluid applies to the rear diff.

I would like to hear what others have learned from their local dealers. (littleblazer - I am not questioning you findings to the replacement fluid. I am hoping that the ATF-DW1 is also an approved replacement fluid to the ATF-Z1.)

Thanks

littleblazer

ATF-DW1 is replacement fluid to the ATF-Z1.
DPSF is SH-AWD differential fluid. I'm ASE mechanic since 1981.

dcmodels

I do not suggest using other than Honda/ Acura fluids. The following is for comparison only.

The viscosities at 100C and 40C are from manufacturer MSDS. The other values are computed. Redline LW = Redline Racing Lightweight ATF. The Honda MSDS for DPSF does not list viscosity, so I have shown the viscosity for a Penrite (Australian) replacement fluid.

120C/ 100C/ ..40C/ .0C/ -20C viscosity Comparison for cSt at degrees Centigrade
5.31/ 7.58/ 38.75/ 285/ 1325 = Redline Racing 62.5%/ LW 37.5% (Synthetic)
..../ 7.50/ 34.00/ 205/ 0798 = RedLine D4 ATF (recommended for ATF-Z1)
5.12/ 7.06/ 29.49/ 158/ 0553 = Honda OEM ATF-Z1
..../ 7.00/ 37.00/ 294/ 1477 = Penrite HDPS (semi-synthetic for Honda Dual Pump Systems)
4.87/ 6.93/ 34.87/ 255/ 1187 = Redline Racing 50%/ LW 50% (Synthetic)
..../ 6.83/ 25.09/ 110/ 0325 = Honda OEM DW-1

The viscosities were computed using the following web site. I do not know just how accurate it may be.
http://widman.biz/English/Calculators/Graph.html
---eof

kimck99

Hi littleblazer,

Thanks for the clarifying. So, are you suggesting that I change out the ATF-DW1 fluid with the DPSF fluid?

I'm surprised with the Acura dealer sold me the the DW1 fluid when I explicitly said I wanted the ATF-Z1 for "rear differential oil change". I guess I need to call another dealer to get a second opinion.

Thanks

JohnH425

Just a quick question.... The dealer chg my rear-differential fluid @ 15000km on my 2007 RDX.... I no longer go to the dealer for regular service(oil/ filter chg.. etc). My car is up for engine oil chg in 2 wks...

Should the rear-differential fluid be chg too??.. How often should it be chg?? Every 50000km??...

Thanks

dcmodels

Did you read your Owner's Manual? Do you observe your MID?

My 2009 RDX OM says to change it for an A6 or B6 report from the MID (multifunctional indicator display). For severe conditions, first time at 7,500 miles [12,000 km], then every 15,000 miles [24,000 km].

My B6 occurred first time at 12,500 miles.

Most services are listed on the Maintenance Minder page of the Maintenance section of the Owner's Manual.

dkswim

this service is to be preformed whenever maintnance minder indicates 6.

maintance minder deffinitions

A:
Clean air filter & air filter box . . . . . . . . . . . . . . . . .(10 mins.)
Top off all fluid levels . . . . . . . . . . . . . . . . . . . . . . . . .(1 min.)
Lubricate all hinges, locks & latches . . . . . . . . . (10 mins.)

and parking brake adjustment . . . . . . . . . . . . . . . .(35 mins.)

Lubricate all hinges, locks & latches . . . . . . . . . . (10 mins.)
Perform starting & charging system inspection:
Check alternator output, full field test,
starter draw test & load test battery . . . . . . . . . . (18 mins.)
Inspect & adjust drive belt . . . . . . . . . . . . . . . . . . . (15 mins.)
Inspect the following items:

Cooling system hoses & connections,

Exhaust system, Fuel lines & connections and
Lights & controls . . . . . . . . . . . . . . . . . . . . . . . . . . . .(10 mins.)

1:

Rotate tires (15 mins.)


Replace dust and pollen filter . . . . . . . . . . . . . . . .(30 mins.)






Replace engine coolant (60 mins.)

JohnH425

Thanks guys....

Hv not seen a '6' since the rear-diff fluid was chg @ around 15000km & hv not chg it since....

Guess I'll wait until I see a '6' comes on to get it chg.....

PANG-S2

I have a question, in the RDX manual for Rear Differential Fluid it says..

Capacity:
SH-AWD differential case
1.0US qt (0.9l)
SH-AWD clutch case
2.8 US qt (2.7l)

Every time I changed this differential fluid at the Honda dealer they will fill it up till about 2.8 before it starts over flowing, I'm guessing that this is the clutch case or whatever u guys been doing since you mentioned around the same amount of fluid? Now, how do we get into the "differential case" to replace that 1 qt of differential fluid. Is there a second fill up plug anywhere? I'm confused.

JCRDX11

How many miles before we need to change this fluid?

dcmodels

Is this the Owner's Manual? My 2009 RDX OM states 2.8 US qt (2.7 L) for the SH-AWD REAR DIFFERENTIAL CASE.

This is actually incorrect. The correct amount, including the 2007-09 models, is 2.67 US qt (2.53 L), at fluid change. The rebuild amount is higher. And this amount is the amount that my 2009 rear differential actually takes, as I have done two rear diff oil changes. 0.67 quarts = 21.4 ounces.

This data is from the 2009 FSM (factory service manual), which covers all models from 2007-09.

I have no idea what the two different capacities are that you have listed. Clearly, there are sometimes errors in manuals.

NO - but it is possible that this reference is to the front transfer case, which has a capacity of 0.45 US quarts, and takes GL4/ 5 hypoid gear oil.
---eof

PANG-S2

Yes this is the back on my 2007 RDX Owner's Manual (last page), and no I'm not talking about the front transfer case which have their own line of information.




The reason I'm asking if there's a second fill and drain plug, because I know for a fact that the RL have two. On the RL both drain plugs are right next to each other but the second fill plug is hidden in the front of the rear diff case which a lot of people missed. And the way my 2007 RDX Owners Manual state this info just made me paranoid. I just hope our RDX doesn't have this second fill and drain plug, because we changed three times already and don't tell me have we been doing it wrong.

dcmodels

The official Factory Service Manual (FSM) which I have, first edition June 2008, does cover the 2007, 2008, and 2009 RDX models. There are separate sections for each model, where appropriate, although in general the three models are exactly the same (according to the FSM).

I purchased my FSM in June 2009, so at that time there was no later edition of the FSM. Or if there was, the Helms Co. did not send the later edition to me.

And my FSM says there is only one drain and one fill plug for the rear differential. And that the fill fluid amount is as I stated above. And also that my own OM (owner's manual) is incorrect. And a second check on the FSM, is the exploded parts diagrams available, online or at your dealer's, which also shows only one drain/ fill plug.

And yes, my FSM has some minor errors as well as my OM. In general, the errors are either obvious or of the type whereby different fluid levels are specified in different sections of the FSM. Having directed tech writers to write manuals for my own engineering projects, it is not too difficult to understand how this happens (errors).

Thanks for posting the page from your 2007 OM. And that is interesting concerning the RL rear diff having two drain plugs. Every year like that, or just some years?

ALTERNATE ATF?
It is interesting that your OM states that Dex III is a valid alternate fluid for both the trans and rear diff, even if only as a temp measure. My 2009 OM and FSM do not state this, probably because Dex III is no longer officially licensed by GM (the 'General').

BUY YOUR OWN FSM?
Check the back page(s) of your OM if you wish to order your own FSM. If I owned a 2007 model, I would be inclined to order the 2009 manual, or even the 2010 manual if it covers the 2007 model. The reason is that the 2009 manual has twice the pages as the 2007 FSM, although it also costs twice as much. The later 2009 FSM may have updated information over the 2007 manual.

ENGINE CAPACITY:
I just noticed that the 2007 engine oil capacity is 4.9 qt from your OM, and the 2009 oil capacity is 5.0 qt. Probably another minor error, or perhaps the factory oil filter has changed slightly.

Actually, my 2009 can take more than 5.0 qt depending upon which filter I use, and how long I let the oil pan 'drip'.

As a side note, the FSM states that the engine actually holds 6.1 qts, but only 5.0 drains on an oil change. That leaves almost 20% dirty oil in the engine, which is another reason why I generally change my oil a bit sooner than the MID requests.
---eof

say what

Rear differential oil change coming up. Thanks for the comprehensive procedures in handling this!

raschkess

Thanks for the procedures on how to change the rear differential oil. I have a 2007 RDX with 17,000 miles and 2004 TL with 36,000 miles. Between my husband and I we've had 30+ honda's over the years and never trust dealers to be as particular with our cars as we are, so my husband does all the maintenance. Acura and Honda no longer publish the maintenance schedule in the owners manuals, (which is extremely irritating) and rely on maintenance minders and the maintenance minder schedule they now have posted on their www.myacura.com only tells you the extreme mileage, otherwise wait for the maintenance code. So I had my 2007 RDX into the dealer with 17,000 miles on it and the service guy tells me that it is "long" overdue for the 15,000 mile rear differential oil change. I never had a B6 code come up. He told me that it is every 15,000 miles it has to be changed. I printed the maintenance minder schedule from myacura.com and the B6 code (which never came up) says "if driving in mountainous areas or trailer towing, then change at 7,500 then every 15,000." It gives no schedule as to normal driving. I drive about 3,500 miles per year with the RDX (winter driving only). He tells me do it every 15,000 no matter what. I know they are infamous for overservicing and upselling. If the B6 doesn't appear, how many miles and/or years should I change it anyway. My A maintenance doesn't appear every either and I still change the engine oil every 12 months. Please advise if you can. Thanks. He also told me the trans fluid is every 30,000 miles and the old honda schedule was 90,000 miles, so did it change that drastically or is he trying to sell fluids (I do buy all my fluids and parts from Acura dealer). My cars are rarely driver over 45 mph!

dcmodels

Well, the following are my thoughts. Certainly not everyone will agree with me.

*************************
… I have a 2007 RDX with 17,000 miles and 2004 TL with 36,000 miles. Between my husband and I we've had 30+ honda's over the years …
*************************
17K miles and 5 years is only 3,500 miles per year – and I thought my 8K miles per year was low. And owning 30+ Honda’s means either you do not keep them very long, or (like a friend of mine) you have a garage full of cars. But if you do not keep your vehicles very long, a lot of maintenance may be unnecessary.

Be aware that I keep my own cars around 20 years each, and the following comments on maintenance are based on keeping my own vehicles _reliable_ for those 20 years.

*************************
… and never trust dealers to be as particular with our cars as we are, … I know they are infamous for overservicing and upselling. …
*************************
Perhaps, depends upon the dealer, and how long you keep your vehicles, and how reliable you wish them to be. Once a vehicle is older than 3-4 years, maintenance should _also_ be based upon TIME, not just MILEAGE. That was the purpose of the older Owner’s Manual’s listing of two different maintenance schedules: SHORT TRIP/ low yearly mileage (severe service) and LONG TRIP/ high yearly mileage. The new MAINTENANCE MINDERS in all current vehicles, are supposed to take into account how many miles you drive per year. BUT …

As you have already stated, you do change your ENGINE OIL once per year, even though the MID (maintenance minder) does not tell you to do so. And your Owner’s Manual (OM) states to do this (change engine oil minimum of once per year). Admittedly, there is no mention about this yearly-limit with regard to the other maintenance items. Still …

If the MID cannot tell you when to change the ENGINE oil, when your yearly mileage is so low, how do you expect it to properly tell you when to do the other maintenance items, such as a REAR DIFFERENTIAL oil change, TRANSMISSION oil change, etc.?

*************************
… My A maintenance doesn't appear every either and I still change the engine oil every 12 months. …
*************************
Modern maintenance schedules are written by MARKETING, not ENGINEERING (the guys who designed your car). The schedules are skewed toward consumer convenience, and competition with other car manufacturers, who are also stating low maintenance schedules. The schedule only has to allow your vehicle to last the warranty period (4 years?), and is not meant to allow your car to last 20 years and 300K miles. So how long do you want to keep your car?

Consider: average mileage for USA vehicles is around 15K miles per year. My MID gave a “A16” code at 12,611 miles and 15 months. A MID is basically designed to report based upon this average yearly mileage. For one thing, it simplifies the algorithm used in the MID computer (I worked 40 years as a programmer). There is no simple way for the MID to check against real-time calendar time, nor if the battery has been disconnected/ replaced, etc. Hence, the directive to change the engine oil at least once per year. Plus, consider the following.

Since you have changed the ENGINE OIL in your vehicle at one year, why would you leave the REAR DIFFERENTIAL OIL for several years (low mileage) before changing it? The rear diff oil is actually ATF (automatic transmission fluid), very different from the old style of gear oil, which was most often left for years inside the rear diff. ATF has a much shorter (years/ miles) life than gear oil.

Any oil becomes ‘worn’ with use, and accumulates moisture (causing corrosion), and wear materials (from use). The additives in the oil are depleted (what is meant by ‘worn’ oil). These things happen even with low mileage, if the time interval is longer than ‘normal’. In fact, oils actually tend to ‘wear’ faster with shorter trips, lower mileages per longer calendar times.

*************************
… My cars are rarely driver over 45 mph! …
*************************
I am not sure why you have stated your normal speed, but perhaps you are thinking that the low speed means the vehicle is used in a low stress service. Actually, the opposite is true. Optimal service is long trips on the freeway at 70mph. Short trips at low speeds is what the OM’s used to call “severe service”, requiring higher and more frequent maintenance. My old Chevy OM states:” Driving a vehicle with a fully warmed engine under highway conditions causes engine oil to break down slower.”

*************************
… If the B6 doesn't appear, how many miles and/or years should I change it anyway. …
*************************
Here is what my own 2009 RDX OM says: “Driving in mountainous areas at very low vehicle speeds or trailer towing results in higher level of mechanical (sheer) stress to fluid. This requires differential fluid changes more frequently than recommended by the Maintenance Minder. If you regularly drive your vehicle under these conditions, have the differential fluid changed at 7,500 miles, then every 15,000 miles.”

So if you wish to maximize the life of your 2007 RDX, then the following is how I treat my own 2009 RDX. I consider low speeds, in traffic, and short trips, to be considered severe service. Also, low mileage per year I consider just as ‘hard’ on the vehicle as if I drove 15K miles per year (because the trips would be longer at higher speeds).

REAR DIFFERENTIAL OIL: I changed the oil the first time at 6K miles, and each additional 6K miles or every year. That oil is ATF, and is not designed for hypoid gears in a rear differential, which is what the RDX has. Also, Honda ATF-Z1 (now DSPF recommended) is NOT a synthetic, but just a normal oil. Once reason for the increase in service intervals recommend by all manufacturers is that now synthetic oils are required.

*************************
… He also told me the trans fluid is every 30,000 miles and the old honda schedule was 90,000 miles, so did it change that drastically or is he trying to sell fluids (I do buy all my fluids and parts from Acura dealer). My cars are rarely driver over 45 mph!
*************************
TRANSMISSION OIL: the RDX OM (owner manual) recommends changing at 30K miles, then every 60K miles, IF the vehicles is operated under the same conditions as stated above for the RDX rear differential, as severe service. Otherwise, you would wait for the MID to state an “A3” or “B3” code. But again, are you going to wait years and years at 3.5K miles per year to change the trans oil? Will your MID ever report a trans oil change? Your decision of course.

While you may not be driving in mountainous areas, or towing a trailer, you are driving at low speeds in stop-and-go traffic. Is the temp high in the summer in your area, or low in the winter? Then your vehicle never warms up in winter, and suffers higher than normal heat in the traffic of summer. Is there heavy traffic in your normal commute, or short trips? The transmission in particular suffers more heat and wear, since every time you hit a traffic light, it has to shift both up and down several times. There is little-to-no shifting on the freeway – the trans just hits top gear and stays there. Shifting causes wear and heat.

Again, whether ATF-Z1 or the new DW-1 is used, neither is a full synthetic oil. Every _other_ car manufacturer now requires a synthetic transmission oil. (and please, no comments that DW-1 is synthetic unless proof is submitted – or better yet, take that argument elsewhere, as there are hundreds of threads currently arguing that point).

Finally, keep in mind that while the current Honda transmissions seem to be quite reliable, in the past decade Honda has lost 3 different class-action law suites concerning transmission reliability. My own thought is that changing the trans oil a bit more often is good insurance, if you want the trans to last a long time.

I change the TRANSMISSION oil in my 2009 RDX every 5K miles. Remember that only 4 quarts of a total of 8.2 quarts are replaced when the trans oil is changed, unlike the ENGINE and REAR DIFFERENTIAL, whereby _all_ of the oil is replaced with an oil change.

AN IMPORTANT POINT ABOUT RESETTING THE MID: if you or your husband is resetting the MID manually, when you change the engine oil, _before_ it hits the 15% limit and requests an engine oil change, the MID will _never_ report any other items. That is because it can only report when it hits 15% (so far as I am aware - could be wrong here, but I get reports only at 15% oil reports).

And when you manually reset the MID, instead of using the special Honda tech-tool, _all_ of the reporting intervals are reset as well. Again, this is my reading of the factory manual instructions. I do not mind being corrected on this point, if someone knows for certain.

The Honda tech tool allows resetting _only_ an individual reporting period, such as the engine oil change period, without resetting any _other_ reporting period.
---eof

wspy

Where can I get the oil pump that you screw unto the bottle?
Autozone maybe

737 Jock

I use an outboard motor oil pump for filling and a MixMizer for topping off, as pictured here. Got both at Pep Boys. This pic was from my transfer case DIY, so ignore the gear oil, it doesn't go in the rear diff.)

lndiferrent

This week I went to an Acura dealer and asked for a rear differential fluid for 2008 RDX. The salesman gave me three ATF-DW1 quarts. Since I've already seen this topic, I asked him isn't DPSF supposed to be used in rear differentials? He told me that ATF-DW1 is a replacement fluid for ATF-Z1 and that is what they use in rear differentials now. Then I looked on the back of the container and it clearly says "Not to be used in rear differential and clutch cases" and I asked him about that. He repeated again that they use DW1 in rear differentials but if I want, he can order DPSF for me since they don'y have it in stock right now. He also mentioned that DPSF costs twice as much.
Since this was a reputable Acura dealer I decided to buy DW1 and trust their judgement. However, something just didn't sound right about that and a couple of days later I decided to ask another Acura dealer in the area for a second opinion. I told them the story and their mechanic immediately told me that I don't want to put DW1 in the rear differential and I should use DPSF instead. They were even kind enough to swap DW1 I got from the first dealer for DPSF - without extra charge.

JLMore

I have a 2011 TL SH-AWD. The very last page of my Owners Manual is the "Service Information Summary" page.
For "Automatic Transmission Fluid" it says, "Acura ATF DW-1"
and for "On models with SH-AWD...Rear Differential Fluid" it indicates, "Use Acura All-Wheel Drive Fluid (DPSF) only."
So, if your vehicle is anything like mine, I think you did the right thing by changing it out.
It seems like the techs are confusing transmission fluid requirements with differential fluid requirements. Which is not cool. Because, while i can't find a warning in my manual specific to using the wrong differential fluid, I certainly find one about using the wrong transmission fluid. Again, in my TL Owners Manual, page 516 (regarding automatic transmission fluid) it says, "NOTICE...Damage resulting from the use of transmission fluid other than Acura ATF DW-1 is not covered by the Acura new vehicle warranty." Again, that is specific to transmission fluid, so it does not seem to be relative to your concern, but is good to know, I would think.

JLMore

*****After rereading the thread, it is apparent that my 2011 TL SH-AWD requires a different rear differential fluid than other Acura models. Again, the information I provided is specific to my 2011 TL SH-AWD--I was not implying other models require exactly the same fluids...just wanted to share what I know about my particular model in an effort to help clear up confusion.*****

alfa75uk

Thanks to all for posting these DIY guides, they are a big help! I changed the rear diff oil last weekend and was surprised to see how dark the drained oil was. Car was stealer serviced at 30000 (currently has 38000). Either the oil wasn't changed or it gets a hard life! I'm going to run it for a couple of thousand then change it again, cheap insurance. Thanks again!

FlopMeister

I have a question about your differential. Why is there a bolt and grommet on the left side of that cross member and then there is an open hole and empty threaded hole on the right side? Did u remove it? I just got my 2012 Rdx and when I looked at the rear diff and saw the missing bolt, I got really scared.
Please advise ASAP!

hotbryan333

Thanks to the OP for great DIY post i did this at home following the procedure

the cost of the fluid was just under 10 bucks per bottle totaling about 33 with tax and the washer.

After the fluid change i instantly noticed much more smoothness in the vehicle.

It drove better than prior to the fluid change, i don't know what could have caused this pleasant feeling, but it is awesome. I thought Tranny fluid might change how it drives but not the rear differential.

And hope that the NEw dw-1 will do the same magic

And i had to jack up the car since my chest would not fit under the car easily

wifesRDXtech

Great post I did my diff, cost me 21 bucks. Dealer wanted 125

737 Jock

Regarding change intervals:

While the RDX was up for an oil change, I extracted some ATF-Z1 from the diff using a MixMizer. There is 20k miles on this diff fluid. This is not scientific or any kind of oil analysis, but you can see that the fluid is only slightly darker than the new fluid in the dish beside it. It still looks very clean, spreads evenly on a paper towel and has no burned odor. It smells very much like the new fluid.

I did my diff the first time at 17k miles, when the MID called for it -- that fluid was fairly dark and contaminated. After that I've been doing it about every 25k miles and it comes out slightly darker than this 20k fluid below. I'm fairly confident that 25k may be a reasonable interval (although there's nothing wrong with shorter intervals).

The next change will be to DPSF.

Bruce Banner

iTrader: (2)

I can't imagine fitting under the car to get those bolts off without jacking it up.
Is there some trick to doing this?
What fluid does everyone recommend? I'm eyeballing the Mobil stuff.