Rear differential fluid change
 

Does anyone have diy instruction for rear differential fluid change? I found post for the 2nd gen and it's doable without jack. I wonder if it's the same with 3rd gen. Thanks.

Follow the maintenance minder's schedule, but here's roughly how you'd do it:


You may also be asked to change the oil transfer case at the same time.

The rear diff has changed a bit since 2nd-gen RDX. and also since 2015 MDX. In terms of DIY fluid change, the drain port has moved around a bit. On 2019 RDX it's on the left ( driver's ) side, near the front of the diff.

Transfer fluid change is usually done along with transmission fluid change, although they are completely separate.

"Normal" service interval for the rear diff should be first change at about 15k miles, then every 30k miles. The MM will adjust this a bit to coincide with oil changes.

Note: I was about to post rear diff fluid changes from the official Honda/Acura on-line service manual, but they are WRONG!

The manual shows a drain bolt at the back of the diff, but I did a reality check under the vehicle and it's on the driver's side. Yeesh. :whyme:

Or do I need new glasses? ( Possible... ) Anyway, now these instructions look OK. The first view is from the back. But if you have a spare tire installed, it will be a bit more crowded. I usually drop the spare.

The second view is from the driver's side looking toward midline. The driveshaft is to the left.

Note the last few steps about running the engine before topping off the fluid. That's because this version of the SH-AWD rear diff has electric hydraulic pumps.


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Note any high quality hypoid gear oil is fine for the transfer case lube; I usually use Mobil 1 75W-90

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@Wander i gotta admit that those procedures are about as simple as it gets for changing fluid, I was expecting a much more in-depth procedure for the transmission ha ha, thanks a bunch for posting those. Also they mention there is a transmission fluid level check procedure that I didn’t see, would you have that by chance? I take it up to the filler hole but just wanna be sure. This will be a piece of freaking cake to change these

In my personal opinion you should always start by removing the filler plug FIRST, them the drain. Contrary to what its indicated on the procedure manual.
Just my 2c

Agree with removing fill plug first. Always. So you can drive it to dealer service if you can't get the fill plug out. :surrender:

Tough to do with no fluid. :doh:

Presumably dealer service has tools not available to most shade-tree mechanics, and most owners probably wouldn't accept "sorry, we couldn't change the fluid because the plug was too tight".

Here's the ATF level check procedure. Sorry about the confusion.


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There is plenty of room to slide under the rear of the vehicle without lifting it, especially if you drop the spare. If the vehicle is tilted, you won't be able to set the fluid level correctly when you refill the rear diff ( or anything else, for that matter ).

The front is more of a challenge to slide under, but that's how I do it. I have jack stands ( 2 sets ), I just don't trust them to support the car when I'm under it. In my foolish youth, I was much more cavalier. But I live in farm country, and farmers make the news by getting crushed by tractors or whatever. Way too often.

Thanks for sharing these files. Jobs like these are so easy to do and can save you a ton of cash. Are these from the online service manual that you pay to have access to or are they available with the materials that come with the car (free online database)?

Pay to play for the online service manual. $10 for 24 hours. $50 for a month. $350 for a year. This gives you access to all Acura vehicles or all Honda vehicles, but not both.

And they make it difficult to download .pdf files. I was doing screen captures, but I just established that if you use the "print" icon to create a screen image, you can then use the browser's export function to generate a .pdf file.

Not that I know of. And there are hyperlinks in the manual pages, so a lot gets lost in translation, unfortunately.

I have a digital copy of the service manual for my TL. Someone was able to post it as a giant pdf file that we were able to download. That is why I asked if it was the pay site or free from somewhere else. The TL document is well over 1000 pages (don't remember and I am on a different computer), but having "forever" access to the service manual is awesome. Just wondering how someone with the service access for a day or month can save a copy of the full manual to refer to over the life of ownership. The current plan is to pick up an RDX when my TL finally calls it quits....it just keeps rolling (which is OK with me since I love that car). Thanks again.

Is this the correct sealing washer??

https://cimg6.ibsrv.net/gimg/acurazi...165158f624.png

42 is the filler washer, 31 is the drain washer, so part 90471-PX4-000, careful buying on amazon, some of the reviews are saying they are getting fake parts on there

Don't tell anyone, but I don't usually bother with replacing the rear diff crush washers. The engine oil crush washer I might throw on if I have one. Especially if I drop the old one in the oil pan and I don't feel like fishing it out.

I'll always prefer / use the new one, but a number of times I've had to re-use the old one. I've never had a re-used one fail or leak.

How important is the part where you have to start the engine and let it idle for 1 minute, then refill? How many shops really do that?

***Double posted by accident

Considering that I don't have a "level ground" available, I am going to bring it to a local mechanic where there is a lift with my own dpsf and pump, I'm sure all they have are Mobil 1 and dirty pumps. Just wondering how anal I will have to be to make sure he follows all the direction. I assumed he will have to bring the car down idle it and lift it up again to refill and I'm sure he doesn't want to do that cause he is in a rush, the line is always crazy at that place.

This version of the SH-AWD rear diff has electric hydraulic fluid pumps and dual hydraulic circuits that generate the force to press the clutch plates together on either side of the diff. I don't know how much tendency there will be for those fluid circuits to drain fluid during a change, but the reason for idling the engine is to spin up those pumps and purge the hydraulic circuits of air.

They will purge themselves anyway the first time the car is driven, but to the extent fluid replaces air inside the hydraulic circuits, the diff will low on fluid by that amount.

Official Part List for Rear Differential Fluid change:

• 08200-9007A - Acura All Wheel Drive Fluid (DPSF) [will need minimum 2 quarts]
• 90471-PX4-000 Washer, Drain Plug (18mm)
• 94109-20000 Washer, Fill Plug (20mm)

I ended up buying in bulk from my dealer. Got 10 quarts + 5 drain plug washers + 5 fill plug washers for $40 total.

I guess you're in this for the long haul... :thumbsup:

did you buy a 10 quart bottle or 10 individual quarts? I'm trying to find the best price to order this online, perhaps in bulk

Is this the procedure for 2018 HS-AWD MDX too?