Has anyone replaced the rear dif. oil yet? I've seen recommendations to change it at 15K or 30K depending on driving conditions. What do you think? I'd like to hear everyone's recommendations.

I'm debating on whether to do it myself or take it to the dealer and have them do it.

 

Won't the MID tell you when it needs to be done? I would go by when the MID tells you to do it.

 

The computer told me to do it @ 9k miles. i thought it was excessive but they told me that the first change out comes quicker and subsequent changes will have a much longer interval....

it was not cheap

 

Haven't done mine yet, but will do it sometime this spring.

I don't know off hand when the RL manual suggests we change it, but on your NSX and my S2000, it's recommended that we change it every 15k miles for severe driving and 30k for regular driving. I change the diff fluid in the S after every track event or after every other oil change.

I've ordered a service manual from Helms, when it gets here I'll scan a copy for you.

My question is which fluid? 75w90? If so, mobil1 or LE607 almasol? Or plain jane Honda VTM-4?

 

That's a shame considering how easy it probably is. There's probably two drain plugs for excavation and one fill. If its anything like other automobiles out there, it should be simple and straight foward.

 

I was in the service dept at 10,900 with MID warnings. The dealer told me it was time for the differential fluid change. I asked how much?? Quote was $60 and I let them upsell me to 12k service at $159 which included an oil change, tire rotation, various checks & "stuff".

 

Candidly I am beginning to distrust having the computer tell me when to have maintenance performed. It's a "black hole"

I would prefer the old standard of having guidelines and adjusting the timeframe/milage based on local conditions.

My Lexus recommends oil changes every 5000 miles. (this seems like a reasonable number, although on all my previous cars I changed the oil every 3000 mi).

At any rate My RL called for an oil change after 4000 miles.

Here is an imagined scenario for you conspiracy types

I can envision the engineer talking w the programmer and arriving at a methodology for computing the oil change interval (and any other maintenance interval for that matter). Then they go talk w the beancounter and He/she says that by lowering the interval by 500 miles the increased revenue to the dealerships would be a total of x Million $ /year. Then some Management type says if 500 miles less makes that much money then why not 750 miles less. it certainly won't hurt the car, and since no one knows the algorithm that we are using, why not make more money.

A fantasy........ perhaps.........
I would bet real money these conversations took place and computations were made. Whether they altered the algorithm is open for debate.

 

Did it myself at 13k miles. The computer said it needed to be done as part of second oil change. Subservice 2, if I remember correctly.

$20 for 4 quart ATF VTM-4, $2 for 4 crush washers, $4 for fluid pump.

Not paying the dealer $175 to do it - priceless

heh heh seriously it's super easy and took less than 20 minutes, once the car was in the air . . .

 

I will not follow the computer suggestions so I left it out of the loop and it does not tell me anything. To me it is annoying to have an electronic reminder of anything and even worse, a reminder that it is time to bend over and grab my ankles - an eloquent description given by bkw on another thread.

It looks easy to do with the exception of having to keep the car level while you do it. I would use only the fluid Honda recommends which I haven't looked up yet. I do have the Helm's Service Manual so I'll look it up. My thinking now is that I will replace it at 30K miles.

 

What is the pump you are talking about? Is that needed to pump the fluid into it once you drain it? What kind and where did you get it?

 

I'm sure he's speaking of the pump needed to get the fluid out of the quarts and into the differential casing. I have a really sweet one I've been using for years now that I picked up at pep boys for $10. You could use a turkey baster, but it'll take significantly longer.

 

Even a turkey baster won't work. The Hypoid chamber fill plug is very tight to the rear crossmember. you need some type of hose to pump the fluid up into the diff.

I got mine at Kragen . . .

 

You might want to double check on that Honda ATF-VTM4 fluid you got for your car. I just looked it up in my Helm's Acura Service Manual (page 3-2) and it says to use HONDA ATF-Z1 (Honda P/N 08200-9001) for both the automatic transmission and the rear differential. I read somewhere else that the VTM-4 is designed for the Honda CR-V

 

You might be correct, but the Acura dealer used 08200--9003A VTM4. which I assume is their P/N for ATF VTM4.

 

It's a different type of fluid for a different application so I suspect the dealer is using something different than the Helm's Service Manual recommends. I've looked it up in other places and they all say to use: HONDA ATF-Z1 which appears to be different from HONDA ATF VTM4. HONDA ATF VTM4 is recommended for the Ridgeline pick up truck among others.

 

Too bad we have no way to actually verify whether such conversations took place, as I would take you up on that offer to bet 'real money'. What possible reason would Acura corporate have to devise ways to allow Acura dealers to make money off customers at the expense of customer perception of the vehicle's maintenance requirements? Your local dealer does not share revenue from maintenance operations with Acura - since Acura wouldn't get a dime why would they do this?

Back on the real topic of differential maintenance . . .

My 2005 RL Service Manual (page 15-102) calls for Honda ATF-Z1 fluid in the following capacities:
Clutch Chamber: 2.7L/2.8 US qt at fluid change, 3.1L/3.2 US qt at overhaul
Hypoic Chamber: 0.73L/0.77 US qt at fluid change, 0.75L/0.79 US qt at overhaul

Hope that helps.

 

Honestly, I think your logic is reversed, if it was even to occur.

OEMs would want a longer service interval, if it was possible, to allow for lower maintenance costs. That way, they can advertise to Joe Blow that our car costs less to maintain than the competition.

The intent of the flexible service system(s) is to allow for a different service interval for an individual driver. Not every driver operates under the same driving conditions, so a "cookbook" service interval is really outdated, actually.

Acura allows up to 10,000 miles between service under ideal conditions. Most people on this forum average between 5500-7000. GM uses a similar system on all of its cars, and the maximum is set for 12500 in most cars, running petroleum 5w30. The avg drain interval on GM vehicles now with the GM Oil Life Monitor (OLM) is about 8500 miles.

Under severe service, oil changes need to be shortened beyond the "assumed" intervals. A good example of this was based upon the real world experiences of two people that I know. One person had a GM minivan with the GM OLM, and the OLM called for an oil/filter change after only 2200 miles in the New England winter. It was indeed the correct service interval due to the cold temps, oil not being brought up to normal temps for the water to be burned off, and as well as the fuel dilution from the excessive short trips and idling. A similar senario yielded an 1800 mile service interval in a similar van.

There is no way for the driver to make appropriate "judgements" on the correct service interval (unless he was servicing it more frequently than the OLM suggests or if he was using oil analysis). There are many additional factors aside from trip length that the system takes into account...i.e. soak times, oil temps, engine rpms, etc.

So if I'd were you, I wouldn't second guess the OLM if it indicated the need for a service. Only extend the service interval if you are using oil analysis.

In regards to the correct fluid for the Rear Diff, I'm unsure of that. It may be either Honda ATF Z-1 or the VTM-4 fluid. If I remember correctly, Honda ATF Z-1 may have been replaced with the VTM-4 fluid in some applications, so I think the two have comparable viscosities. Use the correct one, whichever it may be. I suspect that the VTM-4 fluid may simply be ATF Z-1 with a GL5 "like" additive pack for increased protection in differentials, more than likely.

 

I just checked with my dealer. It is different stuff for different applications. DO NOT use VTM-4 in your RL tranny or rear differential, if you do, you are using the wrong fluid. Honda ATF VTM-4 is designed for the MDX, Ridgeline and other VTM four wheel drive systems.

 

I checked w my dealer as well, and although they billed me for the VTM-4 fluid, they actually put the 'tranny' fluid in. (or so they said). At any rate they told me that using the vtm-4 fluid is wrong, and shouldn't be done, it causes the clutches to bind up.???

 

Again, whichever fluid it may be, use the correct one. My sources are saying that plane Jane ATF Z1 goes in, but personally, that makes me nervous considering the lower amounts of anti-wear additive in an ATF as opposed to a gear lube.

 

I had mine changed at the dealer this past Thursday at 16,000 miles. Was around $85.

 

"a reminder that it is time to bend over and grab my ankles"

A HAHAHAHAHAHAHA

 

Anyone know of a cheap online source for the tranny/diff fluid?

 

It is regular ATF in the RL rear diff...and don't forget about the dual chambers of fluid!!
VTM-4 is for the MDX rear diff.

 

A kindly fellow member pointed out to me that it is probably cheaper to buy the fluids locally, as shipping costs would probably wipe out any savings on the fluid itself. A quick check of eBay and online vendor prices confirmed this-thanks for the tip.

 

For those that have done this change themselves, did you use a lift or pit, were you able to change the fluid with no car lifting aids, or did you premeasure and jack up the rear only? Since I don'tt have a lift or a pit (the wife nixed that in the last wave of home improvements!), I have considered the following approach:

(Park car on level surface before starting work)

1. Drain both cases while the car is sitting level on the ground
2. Jack up the rear only, using jack stands
3. Fill both cases to the lower edge of the fill hole (while the car is on stands)
4. Replace fill hole bolts, finger tight only
5. Lower car
6. Remove filler bolts, let excess fluid flow out
7. Replace filler bolts with new washers, tighten to torque specs.

Since one hole is on the rear and one is on the side, two separate jacking and lowering operations may be needed to make sure that both resovoirs are initially overfilled.

I would lose some fluid with this method, but I can't think of any other way to access the filler holes without taking it to a mechanic.

Comments?

 

I did my differential fluid change today using the above method. I ended up jacking the rear of the car up and down a few additional times, which added to the time required. I spent a couple of hours doing the work, but that included a trip to Pep Boys for a new fluid pump (my old one was broken) and scrounging around for a compatible container to pump from. I used almost 4 quarts of ATF-Z1 (slightly more than what is specificed in the Helm manual), and I drained the main chamber when it was on the stands (which drained more out than it would have if the car was level). There was a smalll amount of metal confetti in the old fluid, which may be why Acura/Honda requires a fluid replacement at such an early interval. The drain and fill bolts came off okay, although I had to use a rubber mallet with the socket wrench to loosen the bolts. I reused the washers by flipping them around (mainly because I forgot to buy new washers). It is obvious when each case is full-the fluid dribbles out until the fluid is level with the bottom of the fill hole. I drove it around the block and rechecked for leaks, of which there were none. I will be taking my wife out to dinner this evening with the money I saved by doing this myself. :-)

 

I just finished replacing the rear differential fluid - easy job. I did the draining and refilling with the car jacked up and put in one more fluid ounce than called for in each chamber. The rear chamber takes 25 fluid ounces (24. 64) and the front one 90 (89.6) to refill. I overfilled each by one fl.oz. I torqued each drain bolt to 35 ft/lb and lowered the car to level again. A trickle of fluid came off each chamber and I proceded to install the fill bolts and torqued to 35 ft/lb each with the car on the ground. I have a small torque wrench from Griot's Garage that fits just right to torque all bolts directly, even with the car on the ground.

The fluid that came out looked perfectly clean, as new as the one I put in. There were no metal shavings of any kind in the fluid that came out of my car. I don't know why the system has called for a change at 7K miles on some cars - I did it at 30K and to me it sure didn't look like it needed to be replaced yet.

 

Whew...glad to see your report of the condition of the fluid.

Over the past few months, I vaguely remember the rear differential coming up in one of my service notices, but can't find any reference to a fluid change in any of my service tickets. With 30,000 or so, I've been concerned about this after reading the posts about fluid changes at what would have been about when my first servicing was done according to the computer's schedule.

One of my service tickets mentions being specific to the Southern region, so servicing the RL appears to be location specific.

I'll mention that the Acura Service Manual (2005) states under maintenance minder/maintenance sub items/replace rear differential fluid, that "driving in mountainous areas at very low vehicle speeds or trailer towing results in higher differential temperatures. This requires differential fluid changes more frequently than recommended by the maintenance minder. If the vehicle is regularly driven in these conditions, have the differential fluid changed at 7,500 miles, then every 15,000 miles."

BTW, the fluid recommended by the manual is Honda Automatic Transmission Fluid (ATF-Z1). Further, BTW, the manual gives capacities for both the Clutch chambers and Hypoid gear chambers.

 

apologies to the prior posters who have already given some of this info...

 

The early changeout is due to the wear-in of the transmission...there does NOT need to be visible metal shavings to indicate the prior break-in process. For example, when you did your first oil change, did you see clumps of metal come out of the oil pan... ???

 

They are visible alright and very easy to see. They are not exactly "clumps of metal", they are more like fine shavings of metal that shine very brightly in sunlight. They accumulate at the bottom of your clean pan so you can see them clearly when you drain the oil into a secondary container for recycling. I have seen these shavings in all my new cars at the first oil change and I've seen them in the transmission oil too. I saw them in both the NSX and the RL - more on the NSX.

I'm sure the engineers recommend the fluid change at 7.5K and every 15K thereafter in heavy duty use like towing because it is needed. I'm not questioning the value of that suggestion and I suggest you follow it if that is the way you use your car.

 

I just got mine done today for $90. The car is only at 12K miles. This seems too soon, but the onboard computer said I needed it. I feel like I got ripped off. And my 10K mile service cost me about $140!

 

Very strange... i have all the fluids to do my tranny and diff fluid and im looking for the 2nd fill bolt on the diff. I see two drains... one on the rear of the diff pointing out toward the rear along with its fill bolt above it. And then another drain bolt on the side but no fill for that one. Can anybody advise where the second fill bolt is? I dont want to drain before i know i can fill back up. Thank you in advance for the help.

 

***NEVERMIND***

Found the other fill bolt also on the side of the diff of the drivers side just right of the axle insertion. Like stated above... legit 20 minute job as thats how long it took me between these posts asking for the fill bolt and completion.

 

I had my RL into the stealer for some maintenance/warranty work (no charge new battery. Thank you Acura) and I was complaining about the rear differential whine. Dealer said that it looks like the rear fluid hadn't been changed (I got the car with 23,000 miles on it) and that might be causing the whine, and they suggested I have the fluid change (to see if it fixes it). So I plan to do it this weekend. Are all of the crush washers 20 mm?

 

I did my rear differential this morning. Didn't jack up the rear: I was able to reach the fill holes with the ATF pump with no problem. All the crush washers are 20 mm. I will have to say that doing the air filter was almost more difficult than the differential. It's a b*tch getting the air filter cover up enough to remove the old filter (then I dropped one of the cover screws below the air box and had to fish it out). Cherry on top was the cabin filter. Five minutes and I was done.

 

I havent had my dif fluid changed since I bought the car 2 years and 30 thousand miles ago, so I figured it couldnt be that bad to change it out myself. Many thanks to the posts above.

The pump I used in this picture was not a good idea. It was very messy. Had to pull the plunger to fill from the bottle then slide under the car to the fill hole. The rear chamber wasnt so bad but the front one requires alot more fluid so it took several trips sliding under and out from under the car. If I ever do this again I'm buying a different pump.

I love these ramp things. Made it easy and quick to raise and lower the rear.

Front chamber drain hole. (towards front of car)

Front chamber fill hole. (located on the same side but near the rear of the dif)

Here is the rear chamber drain hole located on the back of the dif. The fill hole is up and to the right of this one.

 

I was at the dealer about 2 weeks ago getting the B2 service done. And the service advisor said that the tech recommended to have the rear diff oil changed out because of the age of the car. My car has 26k, and is almost 5 years old. I never had the rear diff oil changed, so should I do it? I see their point in saying like how the oil will break down over time, but is this an urgent matter?

 

Here's the pump I used when I did mine last year. It seemed to work pretty well.