Honda Auto Trans Flush Procedure - Official

[Badgerland]

If you really want to save on time, start changing it out 1x only at about 15k. This is what I have been doing and this keeps the "new" fluid levels topped off and working good. As long as you don't try this first when you have 60k you should be fine.

[Black Pearl]

Using 2007 4WD capacities, if you do the math, at the third refill, you have 5.4 quarts of new oil and 2.2 quarts of old in the transmission or 71% new oil. The 4th change only changes that to 81% new oil at 6.2 new and 1.4 old. Each change you progressively drain higher percentages of new oil and end up with diminishing returns. A fifth drain and refill only takes it to 87% new oil at 6.66 qts new and .93 old. This is assuming a 100% mixing between the changes.


EDIT: Badgerland, interesting concept. But some how doing 1X every 15k don't seem like the same thing as doing a 4X at 60000. It does sound like a good maintenance plan if you did a 3 X or 4 X at 60. Anyone know when the MMI calls for a change? I intend to do a 3X or 4 X next year at 30K.

[Badgerland]

Well I don't worry about the cost so far as I bought 24 bottles of Honda ATF for $2 each from a friend who sold his CRV. My thoughts are that if you keep putting "newish" fluid in every 15k that it would be better off than waiting all the way to...say 60k and then doing the 3x or 4x whatever.

JM2C worth and my knowledge of Honda's can fill a thimble at best.

[Black Pearl]

More than I know. Anything I know about Hondas, I picked up here.

I can see merit in what you are doing, and you may be right, the addition of fresh oil every so often my be more beneficial than all in one whack over a long period of time. We have a engineer at work who is not quite a tribologist, but has done a lot of oil studies. I run this by him.

[Badgerland]

Originally Posted by Black Pearl

snip.. We have a engineer at work who is not quite a tribologist, but has done a lot of oil studies. I run this by him.

I chuckled when I read this and immediately thought of the old star wars episode...the trouble with tribbles. Beam me up Scotty!

[Black Pearl]

I consulted my engineering buddy at work about the 1 X every 15 K or 4 X at 60K ATF change question. I explained the deal with the 1/3 oil volume being changed, and sent him the link to Honda’s procedure.

First off I was wrong, my buddy is a Certified Lubrication Specialist and is a member of the Society of Tribologists and Lubricating Engineers.

STLE

Here is the question I posed to my Spiritual Adviser in Tribological Affairs:

“Here is the problem. Owner A. Runs his car for 60,000 miles and then performs the 4X transmission oil change per Honda’s procedure. So that at 60001 miles, he has 81% new oil and 19% old oil.

Owner B says. Hmmm. I would like to refresh the tranny juice more often. I will do a 1 X change every 15000 miles. So at the 60001 miles both cars have had 10 to 12 quarts of new transmission oil put into them. However owner B has doled his out over four 15,000 mile segments. So theoretically he would have still have the 19% original oil but 33% new oil and the remaining at various ages in between.

So the question is which is better for the vehicle. Owner A or owner B?”


And here is his answer:

For me this is a no-brainer. The periodic 1X method is by far the best.

There are two major factors at play….. wear particle generation and additive depletion.

With the 4X method you are running at 40K and 50K and 60K with ever increasing levels of wear particles. The factor is not linear. The more particles present, the greater will be the particle generation rate. With the 1X method you will be constantly flushing out some portion of the particles and should have experienced less particle generated wear when you reach the 60K mark.

Likewise with the additive consideration. With the 1X method you will never dip as low in additives as you will at 59K with the 4X method.

One caveat is that if you use the 1X method you cannot change over to the 4X method during the 60-120K period.***

Also, I really don’t like the thought of the power flush. I salute Honda for recommending against it. (I once tried it on a Corsica trany at the advice of my mechanic.
Very shortly thereafter a valve became clogged. Fortunately it was easy access for the trany shop so the bill was minimal. My local trany shop does not advise the power flush and does not offer it.)”



***I questioned what he meant by not changing over to the 4 X method. What he meant was that one can not use the 1 X at 15K method at 60K then decide to do the 4 X at 120 K with no additional 1 X changes. If you decide to go to the 4 X method with no further 1 X methods, then you should do the 4 X method at the beginning of the 4 X interval period.

Therefore if one did the 1X method up to 45 K, did a 4 X at 60 and a 4 X at 120, that would be acceptable.

Doing a 1 X up to and including 60 and a 4 X at 120 K is not acceptable.

The only exception I would take on this is that if you have an extended warranty that is valid for longer than 60K, I would use Honda’s procedure to keep your warranty in effect.

My hats off to Badgerland…the honorary tribologist of the month!

[Badgerland]

Yea...I did SOMETHING right!

Ok, let me re-phrase - At least I didn't do something stupid again.

[RinconVTR]

ORRRRR....forget the whole drain, add, drive, drain, add, drive, drain, add......argh...I dont have time for that crap!

Simply drop the 3qts at the same time your dropping the oil. (or every other oil change is what I do).

[MrClean]

Thank you for the procedure for changing the tramission fluid, appreciate your time, take care. Mrclean.