Transmission Flush Timing Question

[LexKid630]

I have an AWD 03 rx300 35,500 miles. Just got it a few months ago CPO with 33,xxx miles on it. Great condition.

The day i got it, i looked at the transmission fluid (hot) and it was perfectly clean, pinkish-red, and smelled brand new...looked brand new!

after experiencing the transmission failure almost twice, i have decided that this time i'm going to try to prevent it better...the only thing is, i don't see the point in doing a transmission flush if the fluid looks and smells brand new...

If the transmission fluid is clean and smells perfect, is a flush really needed at all? wouldn't it be a waste?

But the next question i would ask me, would be... well then WHEN do you do the flush? When the fluid starts to get dark and smells bad? is it too late at this point?? I mean you can't check it everyday..and in a few years my daughter will have it, and i know she'll never check it.

Does anyone else understand why i'm having a little trouble on this subject?

I know you're all probably cursing at me for bringing this subject AGAIN, but i'm still not clear as to when to start the flush....

I know many say that ever 15,000 miles....but why that often? If the fluid is good why change it?

please don't be mad i'm just still confused :( Thanks

[TunedRX300]

Check at every oil change. I would not flush the tranny, play safe and do drain and fill with Toyota T IV ATF. No need to change if your ATF are still cherry-colored.

[RX in NC]

After our original transmission was replaced under warranty at about 48,000 miles, I researched the issue for several weeks and decided upon 30,000 mile transmission fluid drain-and-fill intervals. I also wouldn't recommend flushing because after researching this option I came to the conclusion that the procedure involves far too much risk. Dredging up settled gunk and pulling it through the system in an effort to extract it can create havoc with any automatic transmission. Do drain-and-fills at 30,000 miles regardless of how clean your existing fluid appears and you just might have a fighting chance of keeping the transmission alive a lot longer. All in all, it's relatively cheap transmission insurance and a snap to do yourself right there in your driveway.

[wwest]

Personally I do not believe that replacing ATF on some scheduled will result in substantially extending the transaxle service life. But I do believe that it should be replaced if it starts to look or smelled burned.

I quite firmly believe the premature failures are the result of undue wear of the clutch frictional services due to the ECU commanding an upshift during coastdown periods and then having to quickly downshift with little internal hydraulic pressure available.

Toyota/Lexus "fixed" the premature transaxle failures in the RX330 by going to DBW and delaying downshift until enough hydraulic pressure was available.

[lenore]

Personally I do not believe that replacing ATF on some scheduled will result in substantially extending the transaxle service life. But I do believe that it should be replaced if it starts to look or smelled burned.

I quite firmly believe the premature failures are the result of undue wear of the clutch frictional services due to the ECU commanding an upshift during coastdown periods and then having to quickly downshift with little internal hydraulic pressure available.

Toyota/Lexus "fixed" the premature transaxle failures in the RX330 by going to DBW and delaying downshift until enough hydraulic pressure was available.

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Ok, What is DBW? By the way I have asked my wife to use the overdrive button selected while driving in heavy traffic, stop and go. What is your opinion?

[monarch]

I know many say that ever 15,000 miles....but why that often? If the fluid is good why change it?

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Because the 15,000 mile change interval is a proven method of extending the life of most automatic transmissions. Hundreds of AAMCO franchises would probably go bankrupt if everyone changed their fluid every 15,000 miles No RX300 owner here that changed their fluid every 15K has reported a transmission failure. So 15K drain and refill intervals are cheap insurance against transmission failure due to fluid deterioration.

Owners who are commonly stuck in bumper to bumper rush hour traffic should change the fluid every 10K because fluid temperatures can spike up to around 250 degrees under such conditions which rapidly oxidizes the fluid.

Owners who live in rural flatlands like the upper Midwest can probably go 30K between drains

because the fluid temperature stays relatively cool (only 155 degrees) when driving at moderate speeds (45-75 MPH) on flatlands.

The FWD models appear to be better engineered to control excessive rises in fluid temperature during rush hour traffic conditions and that's probably why FWD owners don't hardly ever report seeing their fluid turn black & smelling burnt.

[TunedRX300]

The purpose of changing ATF is to make sure ATF is fresh, why changing it when it IS fresh? Toyota T IV is not cheap, what next, drain and fill every 500 miles?

Please don't give me this "what is in owner's manual is just minimal" crap since the warranty is honored. My 00 Owner's Manual Supplement says replace tranny fluid at 60K, this is under stressful condition, e.g. you tow a trailer.

[jbarhorst2]

DBW = Drive By Wire.

I change my fluid every 10,000. I figure it's easy and cheap insurance. We'll see how it does for me. 2001 with 50,000 so far.

Tom

[LexKid630]

do you think it's safe to say that if someone were to drive 40,000 miles a year, over 3 hours a day, would have more problems with the transmission fluid heating up? Maybe this is what happened to me?

What do you reccomend to someone who may not even hit 8,000 miles a year, and who only drives maybe 10 minutes a day, in mostly city situations? if they wanted to keep their AWD for many, many years?

[TunedRX300]

HWY miles are the easiest on the car if you don't race like a maniac. There is minimal wear when you cruise at 70mph on 4th (99-00 RX300) or 5th gear all day long. I agree with Mr West on the main source of heat is generated during gear shifting.

[monarch]

do you think it's safe to say that if someone were to drive 40,000 miles a year, over 3 hours a day, would have more problems with the transmission fluid heating up? Maybe this is what happened to me?

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The fluid temp would stay at around 150-160 degrees all day long if you drove on a flat highway, in cool or moderate weather, but if you also sometimes got stuck in traffic jams in hot weather with the air conditioning on or did a considerable amount of stop and go suburban driving in hot weather the fluid temperature could spike up to around 250 degrees and start burning. I remember at one time you said you drive with a heavy foot on the gas pedal when moving away from stop signs and stop lights. That could add even more heat.

Now if you currently drive only 10 minutes a day each way to work the fluid would not hardly have a chance to get really hot and should stay clean and fresh looking a pretty long time.

[monarch]

The purpose of changing ATF is to make sure ATF is still good, why changing it when it is still fresh?  Toyota T IV is not cheap

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Preventive maintenance that is not performed preventively is not preventive maintenance - it's corrective maintenance. Lubes, filters, coolant, spark plugs, oxygen sensors, etc., all need to be replaced BEFORE they lose their effectiveness if a Toyota / Lexus owner hopes to become a member of the Toyota 400,000 mile club.

Toyota Type T-IV fluid costs $3.80 a quart where I live. 4 quarts every 10,000 miles = $16 = only $320.00 total expense to drive 200,000 troublefree miles. Now compare that to the $1,000 cost of a Lexus extended powertrain warranty or the $3,000 cost of a rebuilt transmission.

It's bewildering to me that some owners think it's outrageous that a $45,000 car needs $320 worth of fluid changes in order to last 200,000 miles, but then they think its normal and acceptable to spend $1,000 on an extended powertrain warranty that offers protection against component failure for only the first 100,000 miles. I think these owners need to reverse their priorities and start investing in frequent preventive maintenance instead of buying fancy warranties.

[TunedRX300]

User's Manual is an official Lexus document to state what is needed before parts become ineffective. 60K is what Lexus recommend for severe driving condition "Only if vehicle is primiarily operated while towing a trailer or using a car top carrier". Pouring Toyota T IV ATF into the tranny indiscriminately while ignoring the true cause of tranny failure and playing the guilt game on end users is not an effective way to prevent tranny failure.

[wwest]

User's Manual is an official Lexus document to state what is needed before parts become ineffective.  60K is what Lexus recommend for severe driving condition "Only if vehicle is primiarily operated while towing a trailer or using a car top carrier".  Pouring Toyota T IV ATF into the tranny indiscriminately while ignoring the true cause of tranny failure and playing the guilt game on end users is not an effective way to prevent tranny failure.

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RIGHT ON...!!!

[LexKid630]

HWY miles are the easiest on the car if you don't race like a maniac.  There is minimal wear when you cruise at 70mph on 4th (99-00 RX300) or 5th gear all day long.  I agree with Mr West on the main source of heat is generated during gear shifting.

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just wondering why you said (99-00 rx300)...does this mean that the 01's and newer are different?

[monarch]

Pouring Toyota T IV ATF into the tranny indiscriminately while ignoring the true cause of tranny failure and playing the guilt game on end users is not an effective way to prevent tranny failure.

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We've never heard of a case of RX300 AWD transmission failure unless the owner allowed the fluid to get black and burnt. We've also never heard of a case where the fluid got black

and burnt during the first 20K miles of transmission operation. Since 10K fluid change intervals like jbarhorst2 is practicing virtually eliminates the chance of the fluid ever getting black and burnt, chances are high jbarhorst2's transmission will survive for alot of years and miles.

I would be willing to admit the RX AWD transmission has an internal engineering defect if someday we hear from an owner who experienced transmission failure despite frequent fluid chances since the time the vehicle was new. Until then, my belief is the only problem with the RX AWD transmission is an external one; i.e. the external fluid cooler built into the wheel well doesn't sufficiently cool the transmission fluid well enough during congested city traffic driving conditions and that frequent fluid changes can likely mitigate this defiency.

[SKperformance]

No tranny cooler will cool a transmission fluid adequetly in stop and go traffic, it is located at the bottom of the rad and has no fan for it.

You want to cool the fluid in stop and go traffic ,turn on your a/c it will lower the temps from 230f to about 180-190f in 90degree weather.

As mentioned before it seems to be an issue with the TC locking up too easily and often when additional power is still needed. By doing this if you press hard on the gas to create a downshift it causes the fibre backing on the TC to shear off and allow fibres to float in the fluid. The fibres cannot be removed by the filter as it is only a screen . So adding an external filter helps to remove the tiny fibres to keep them from blocking up the valve body which is the main problem.

So you want to reduce heat ,turn you a/c on.Remeber your tranny still does need some heat to work properly.

You want to extend the fluid use an external filter to catch the debris.

You want to circumvent the whole situation ,turn the O/D button off when you know you want to downshift to . This lets the tranny disconnect the T/C without having excess torque when released to destroy it.