Questions about transmission fluid

1- I keep on hearing that only Honda transmission fluid should be used. When
these words come out of a dealer I dont pay much attention but as far as
Hondas go everyone seems to be suggesting the same thing. Is it really
necessary?

2- Is transmission flush recommended?

3- What is the difference b/w when a dealer changes the transmission fluid
for $180 and when a regular mechanic does it for much less?

Ok I am a bit paranoid when it comes to transmissions mainly cuz I had a lot
of transmission problems with my old car

Thanks,
W

 

Absolutely not. Honda recommends drain & fill on the transmission. You can
do it yourself. It's actually less of a pain than changing the oil. Hondas
do not have a filter to change, you just drain it out, put the plug back in
& fill it.

Nothing, unless the regular mechanic doesn't use Honda fluid, then you have
a transmission that doesn't work right.

 

Year and model please. That makes a difference.

No. Drain and fill only.

He uses generic Dexron-III instead of genuine Honda ATF-Z1. And he only
does a drain and fill once.

And why was that, pray tell?

 

Required. This isn't the 70s anymore; that transmission is highly
engineered, down to the fluid. The fluid is more than just the energy
carrier. It's an integral piece of the transmission. Honda knows
precisely what's required for it all to work together; others, more than
likely, don't.

Same with Toyota.

Same with their coolants anymore, too.

It's specifically NOT recommended. To exchange trans fluid on a Honda,
you drain/drive/fill several times over. That's all.

If the "regular" mechanic (they're all "regular" mechanics, no matter
where they work) does a simple drain and fill, and uses Honda fluid, and
doesn't screw up the drain plug or over/underfill it, absolutely nothing.

Maybe because you flushed it and used Honest Joe's Auto Parts
Transmission Fluid--"Our Own Brand"?

 

97 accord ex 45k miles (mostly garaged)

I will ask my mechanic to drain and fill three times using honda ATF-Z1

My old car was an 02 stick shift corolla with just 70k miles. After the
clutch got replaced, the car started shaking in the first gear with clutch
fully pressed. By accelerating without releasing the clutch, the shaking
used to increase but also disappear after a lil while . Hyrdaulics were
changed no avail. The dealer said that the clutch was bad...the clutch
assembly was opened but no problem found...mechanic said tranny....i am a
student so i went for a used tranny...the tranny was replaced three times no
avail...finally sold the damn car hehe. In any case I also think the clutch
was bad... but I realized it after wasting $2k.

W

 

Yes. Well, only if you want your transmission to operate properly and
last a long time...

NEVER. Drain and fill 3 times, with some driving between each cycle...

Make sure they are doing the same service, ie: draining and filling
multiple times with OEM fluid. If they are, then nothing. Dealerships
tend to charge more for service...

I have owned 3 Dodge Caravan's. I know all about tranny issues... ;-)
So long as you follow the above, your tranny should last a long time,
unless you have one of the Accords with the known issues, and then your
warranty has been extended to cover it...

 

2- Is transmission flush recommended?

Do you really need to do it 3 times? The service manual doesn't say.

 

capacity is ~4.5l. can only drain ~1.5l at a time. the change is
therefore achieved by "dilution".

even just one change makes a difference - it removes a lot of the crud -
but it can never be the whole solution.

 

Do you really need to do it 3 times? The service manual doesn't say.[/QUOTE]

The service manual addresses a simple change as being a drain/fill
procedure, but it also (at least newer manuals) talks about a complete
replacement as doing the drain/drive/fill multiple times.

 

The Honda book doesn't say it needs to be done more than once. The FSMs on
my Nissans both give the same advice: drain it, fill it, drive it, check it.
Repeat until it is the right color and smells right, up to three times.
This makes as much sense as anything I've seen on the subject.

 

That is commonly accepted as the number of times it takes to pretty much
completely replace the fluid.

When you drain it, there will still be a significant amount of fluid in
the car. You are looking to dilute it to be close to original formulation...

 

The owner's manual says to do it once, and that's what the service
schedule is intended to accomplish.

The "drain and fill 3 times routine" is mentioned, but this is
specifically to get rid of contamination caused by using non-Honda
fluid. At that point, you do have to get the majority of the fluid
out.

That's what the Honda shop manager told me when I asked about this.
They only drain and refill once for a tranny fluid change, in other
words.

That's probably enough in most situations. There are plenty of people
doing more, and I'm marginally one of them. Let the appearance and
smell of the tranny fluid be something of a guide.

My Accord V6 has 28,000 miles and the fluid looks and smells almost
like new. That means one fluid change is all it's getting until it
gets considerably more miles.

My MDX has 28,000 miles also, and the fluid smelled somewhat nasty and
was turning brown. The first time I changed it at this mileage, the
appearance really didn't change, it still looked bad. The second
change (6 miles later), it looked pretty good. Now I'll wait until
the end of the summer heat and change it again. And, then probably put
it on a 15,000 mile routine for a single drain and fill as long as we
have it.

Remember, you get a higher percentage of contaminants out at higher
mileage because they've built up more (so each change makes more of an
impact, percentage-wise). It makes some sense to change it fairly
often after 45,000 or 60,000 miles. But not much sense to change it
very often before then. You're only trying to dilute the contaminants
to a reasonable level. That is, you're diluting the contaminants to
what the transmission would have at, say, 30,000 miles. Each change
after that brings the total contaminants back in line with that 30,000
mile baseline.

Or you can change fluid like crazy and perhaps achieve a 15-20,000 mile
baseline. But the dilution method will never get you even 80% much
less 90% "new" fluid, and the tranny doesn't need that anyway. The
math is an interesting study in futile maintenance. Each successive
change gets about 40% of the remaining contaminants out, so the law of
diminishing returns sets in pretty fast.

 

but as you started out by saying, the "3 times" routine is essential if
the wrong fluid was used.

 

I have a 1999 Accord EX V6. At about 95 Kms I had the tranny replaced
due to slipping. Once they put in the new tranny I switched too Castrol
Synthetic ATF. Once I switched I noticed the shifts were smoother and
generally the car ran better, seemed to have more power, maybe just me.
I know have 210Kms on the car and the tranny still shifts smooth and
has been serviced regularly by the local garage who is a Honda
specialist. I would be interested if anyone else has gobe this route
and what are your results.

 

i wrote castrol a while back and asked them if any of their atf's met
honda specs. they said "no", and that i should stick to honda atf. and
for my older civics, i can tell you from experience that it's always
caused severely harsh shifting - that's why i wrote. with non-honda
fluid in my 89 civic, you think the transmission is going to rip itself
free of the mountings at full power. returning to honda atf returned to
smooth shifting.

that said, about 98 or 99, honda got more sophisticated in their control
module programming - they retarded the ignition timing during the shift
so the power drops way back allowing smoother meshing of the new ratio.
[now, it's even more sophisticated with fly-by-wire - they throttle
back, not just retard ignition.] you seem to be benefiting from that,
but personally, i'd still use honda atf regardless.