Acura MDX SUV Forums banner

1 - 17 of 17 Posts

·
Registered
Joined
·
18 Posts
Discussion Starter #1
Ive bought a gallon of vtm4 oil from Honda dealership to change out my rear differential oil. Now when I shift to different gears in park position i can hear the gears rubbing against one another. Read up online and found that I need to use dpsf oil but not definitive.

What do you guys recommend next?
Thank you in advance.

Sent from my SM-N960U1 using Tapatalk
 

·
Registered
Joined
·
241 Posts
Ive bought a gallon of vtm4 oil from Honda dealership to change out my rear differential oil. Now when I shift to different gears in park position i can hear the gears rubbing against one another. Read up online and found that I need to use dpsf oil but not definitive.

What do you guys recommend next?
Thank you in advance.

Sent from my SM-N960U1 using Tapatalk
VTM-4 fluid is correct for rear differential MDX through 2006. Only the 2005 and newer RL require DPSF.

Have you already changed the fluid in the case between the rear wheels with the VTM-4?

Are you saying if you are in park with your foot firmly on the brake, after shifting to either D or R and before releasing the brake you hear "gears rubbing"?

Does this mean a grinding sound? Or a rubber rubbing together sound?

Either way nothing turns in the rear differential until you release the brake. So the two events are probably unlucky coincidence and have nothing to do with each other if I understand the above right.

I had a rubber rubbing type sound when in reverse from a stop I start reversing up an incline. I had old and low VTM-4 fluid and replacing it stopped the sound.

If you didn't do the trick about driving around the block after the refill, and adding more VTM-4 fluid to bring it back up to full, I'd do that.

Sent from my SM-N950U using Tapatalk
 

·
Registered
Joined
·
18 Posts
Discussion Starter #3
Thank you for helping out with my question. I'll attempt the refill trick. Yes, Ive changed the rear differential fluid with vtm-4 and then it's making that gear rubbing sound when I shift from drive to neutral, reverse and Park. The sounds are like when you are parking on an incline and shift with foot on brake. Driving around I could not hear anything.

The front transfer case, I've used gear oil xx90 from orielly.

Sent from my SM-N960U1 using Tapatalk
 

·
Registered
Joined
·
241 Posts
Thank you for helping out with my question. I'll attempt the refill trick. Yes, Ive changed the rear differential fluid with vtm-4 and then it's making that gear rubbing sound when I shift from drive to neutral, reverse and Park. The sounds are like when you are parking on an incline and shift with foot on brake. Driving around I could not hear anything.

The front transfer case, I've used gear oil xx90 from orielly.

Sent from my SM-N960U1 using Tapatalk
I have no sounds when I park on an incline and shift with my foot on the brake, other than a soft thud as the transmission shifts into gear.

If the car is stopped when shifting the inputs to the front and rear differential are not turning, so I doubt the noise is coming from there.

I'd check my engine mounts just to be sure. Then I'd suspect your transmission fluid pressure isn't building and releasing fast enough due to debris or leaky seals or solenoids.

As a cheap thing to try, I would replace my transmission fluid, unless you know it is full and changed on schedule. Hondas are apparently very sensitive to having fresh and full fluids.

Sent from my SM-N950U using Tapatalk
 

·
Registered
Joined
·
18 Posts
Discussion Starter #5
I've brought the car 3 weeks ago and the first thing I did was change out the transmission fluid. I could do that again. This sound is like when you are on an incline and put the car in gear. Instead of a thud sound, it definitely sounds like gears are rubbing together.

Everything was in great shape and just happened right after I did the differential front and rear oil change. Will do the refill trick and report back.



Sent from my SM-N960U1 using Tapatalk
 

·
Registered
Joined
·
241 Posts
I'll have to test it again, maybe on an incline shifting from park to drive mine has more of a single metallic "tang", which probably has something to do with the parking prawl disengaging under more tension. I can lessen it by when I park putting on the emergency brake, releasing the brake pedal, and then shifting to park. That eliminates almost all extra pressure on the parking prawl if the emergency brake is on tight enough.

But when these cars are in top shape, there is definitely no gear grinding sounds I've ever heard under any condition. I've never heard any gear mesh whine really either, which is generally only audible for some cars when going fairly quick, over 40 with light acceleration.

There is only one noise I've heard which is more of a metal scraping sound. It only happens when the car has set for more than a day, and I start moving. For a couple of seconds, and then for the first application of the brake it makes a metal scraping sound. I'm pretty sure this is the brake pads wiping surface corrosion off of the brake rotor. I don't know why this car is more susceptible to that than other cars I've had. I assumed either the rotor alloy corrodes slightly faster, or the brake pads are a little more aggressive.
 

·
Registered
Joined
·
1,676 Posts
My MDX's rotors would start visibly rusting by the time I was done drying the car after a wash. Most other cars I've owned are the same - not really a problem, though it's nearly comical how bad it can look when I wash my current BMW wagon, and don't drive it for a couple days. And of course, I also get that light grinding, scraping noise applying the brakes for the first time, though it lasts only for one or two revolutions of the wheels. I suppose it all has to do with metallurgy - I'd guess that steel that doesn't rust immediately doesn't have the right characteristics to use as a rotor.
 

·
Registered
Joined
·
18 Posts
Discussion Starter #8
I've put in almost half a quart of vtm4 and now shifting sounds are much quieter. Almost the same as before fluid change.

I have read that people are making 2nd or 3rd transmission fluid change to really clean it out. Does that help? Should I use OEM or Orielly fluid? O'Reilly is nextdoor.

Sent from my SM-N960U1 using Tapatalk
 

·
Registered
Joined
·
241 Posts
Does it help over time... Most likely. Will you notice an immediate difference, probably not.

On a new used car I would do it twice in the first couple of months, then only once each year to slow roll the change.

I would use either OEM or Valvoline MaxLife as both are the most recommended fluids on Passport and Odyssey forums for these transmissions with known problems especially through 2004. I would not use anything else unless it is a high quality synthetic.

Also LubeGard Platinum is a highly recommended additive. I use it.



Sent from my SM-N950U using Tapatalk
 

·
Registered
Joined
·
1,676 Posts
What Colin said!

Every time you change the fluid (or more accurately, every time you do a drain-and-fill), you get about 2/3rds of the old fluid out. So the amount of "old fluid" goes down by 2/3rds every time. You don't have to worry about getting 100.0000% out, but a second or third drain-and-fill will get you pretty close. New tranny fluid is the cheapest, smartest insurance you'll ever buy for your Acura!
 

·
Registered
Joined
·
18 Posts
Discussion Starter #11
So I went and got OEM atf for my MDX and boy did it make a difference. Everything is smooth sounding now. Will do another change in about 1k miles. Thank you for everything.

Sent from my SM-N960U1 using Tapatalk
 

·
Registered
Joined
·
414 Posts
FYI for next time you change the rear diff fluid. You have to fill it up till it just starts to run out of the fill hole, so the vehicle needs to be as level as possible. Doesn't matter if the manual says 2.2 litres or whatever - I fill till it runs out of the hole as per the shop manual.

After I do the initial fill, I put the fill bolt back in and I drive to an empty parking lot (a very nearby parking lot so the fluid doesn't heat up too much) and drive several figure 8's (to get good left and right directions). Every time I do this and return home to check the level, it needs to be topped up, despite it appearing full before the figure 8 driving.

I now have 430 000 kilometres on my 2006 and have done many, many rear diff fluid changes and never heard any weird noises after the fluid change.

As an aside, 430 000 km and everything works (except that damn bluetooth module), including the A/C which is original. I sometimes prefer driving my 2006 over my 2014, especially if there's deep snow, as it sits up higher with greater approach and departure angles to the bumpers.
 

·
Registered
Joined
·
18 Posts
Discussion Starter #13
Thank you and I will keep that in mind. This is such a fun car to drive I should have gotten it many years ago. I'm definitely going to drive it until the wheels fall off.

Sent from my SM-N960U1 using Tapatalk
 

·
Registered
Joined
·
32 Posts
How often should you change the diff fluid? I don't think I have ever changed it in 4 years of ownership and 75,000 miles of driving (from 183k to 258k).
 

·
Registered
Joined
·
1,676 Posts
Honda lists the VTM-4 rear diff fluid change interval as 30,000 miles. Fluids are the best and cheapest insurance you'll ever buy for your car.
 

·
Registered
Joined
·
32 Posts
Thank you and I will keep that in mind. This is such a fun car to drive I should have gotten it many years ago. I'm definitely going to drive it until the wheels fall off.

Sent from my SM-N960U1 using Tapatalk
you might be driving it for a while. I am betting my 2005 MDX will last till about 350-400,000 miles. Hopefully it will be the last car I will own.
 

·
Registered
Joined
·
18 Posts
Have you already changed the fluid in the case between the rear wheels with the VTM-4?

Are you saying if you are in park with your foot firmly on the brake, after shifting to either D or R and before releasing the brake you hear "gears rubbing"?
 
1 - 17 of 17 Posts
Top