Transmission Fluid

[pastin]

I had my oil changed tody on my 2000 RX300 and they stated that my transmission fluid was too dark in color. Any ideas what causes this or if the fluid is just darker than normal. It only has 53000 miles on it.

[jbarhorst2]

Sounds like it was very dirty.

Did they say if it was burnt, or that it was just dark?

Have you ever had the fluid changed?

[wwest]

At 38k miles the fluid in my 01 AWD RX300 smelled and looked burnt. MY RX has the towing package, extra fluid cooling radiator in the right front fenderwell area, and the hitch was removed the first week I owned the NEW RX.

According to the owners manual the fluid is good for the entire life of the transmission. I contacted customer_satisfaction_inquiries@Lexus.com

and was told each time to take the vehicle to the dealer.

I was told by the dealer that the new recommended fluid change out for my RX was 15,000 miles.

I now firmly believe the new RX330's hesitation problem is directly related to the RX300 series burnt fluid problem. The RX330 has an e-throttle and Lexus has alleviated the burnt fluid problem by delaying the onset of engine torque delivery when the transmission is "caught" in neutral while the vehicle is still moving forward.

[pastin]

Sounds like it was very dirty.

Did they say if it was burnt, or that it was just dark?

Have you ever had the fluid changed?

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Both they said it was dark and smelled burnt

No i have never got it changed what interval should it be changed at?

[ColinBarber]

I now firmly believe the new RX330's hesitation problem is directly related to the RX300 series burnt fluid problem. The RX330 has an e-throttle and Lexus has alleviated the burnt fluid problem by delaying the onset of engine torque delivery when the transmission is "caught" in neutral while the vehicle is still moving forward.

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I don't think the transmission shifts into neutral when moving. Mine certainly doesn't otherwise you would see the revs go almost down to idle speed. Try shifting into neutral when going along and you will see. What you are assuming is the box going into neutral is probably just the fuel-cut as you come off the accelerator fuel is completely cut and at about 1100-1300 rpm fuel is restored and you can feel that (you also see it via the mpg figures on the fuel computer)

Many people believe the transmission issue is to do with the viscous coupling generating extra heat and could well be true because the FWD versions don't have the same problems.

The RX330 doesn't have the VC and it also has a different gearbox to the RX300 so doesn't have the same issues.

[wwest]

A couple of notes from the 2001 RX300 Lexus shop manual might be of interest.

Anytime the brake pedal is depressed enough to activate the brake lights the torque converter lockup solenoid is disabled, deactivated. That would undoubtedly result in a reduction of engine drag torque but would likely only be felt by the driver if the brake was not actually "applied".

The second thing is that the shift pattern indicates an upshift, from 3rd to 4th, with the throttle fully closed, at 21 to 24 MPH for the FWD transmission and at 19 to 23 MPH for the AWD. Apparently it then shifts back into 3rd at 11 to 14MPH (both). Since the shift pattern shows no further shifts as the vehicle continues to slow should we presume it remains in 3rd until we come to a full stop?

Shifting upwards, 3rd to 4th(OD) during coastdown would certainly give one a "slingshot effect", feel.

I can't find anything in these manuals relating to shifting at or near coming to a full stop but maybe someone out there has the RX330 shop manuals and can lend some additional light on this matter.

[jbarhorst2]

I change my fluid (pan drain and refill) every 10,000 miles.

I think it's cheap insurance.

I know they say you can go longer (15,000 to 30,000 miles), but it's easy to change.

Tom

[wwest]

That's ten times in 100,000 miles, ten times more chances to screw up something, even DIY, that shouldn't otherwise be bothered with.

Burned transmssion fluid at 38k miles, or less, in a vehicle that doesn't require any fluid service at all, according to the manufacturer, for the life of the transmission is undoubtedly indicative of a more serious problem somewhere in the transmission.

[rbrown2769]

There are something wrong with rx300 transmissions, I am not sure what it is but I have had two failures in the last few months. Lexus need to correct this problem...

[lenore]

There are something wrong with rx300 transmissions, I am not sure what it is but I have had two failures in the last few months. Lexus need to correct this problem...

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Thank you for your comment, Yes as more people participate we are learning that indeed the RX300 AWD has a serious transmission problem. Make your concerns heard at Lexus of America. They will never admit the seriousness of the failure until all of the AWD RX300 customers speak up. Your tranny is probably close to being toast. Sorry, join the rest of us in our grief with such a poor design that is not being addressed by Lexus. What a dissappointment for what could have been a good customer experience. Just wanted you to know it will cost $4400 or more if you go past warranty. Remember you only have 6 years or 70k miles to take advantage of the warranty. Do not let Lexus shun you off, Tell them the burnt fluid indicates failure and you want a new transmission.

[monarch]

lenore, for 30 years, Toyota Motor Company has been making the most reliable and durable cars in the world. But throughout Toyota's history, engineering goofs have been occurred here and there, mainly, ironically in its luxury model lines.

In any case, all the complaining in the world isn't going change a thing because Toyota has been extremely consistent in what it does - both good and bad.

Instead of whining and complaining, Toyota owners that end up with engineering goofs should focus their energies on doing things to minimize the consequences of the goofs. In your case, that means changing the transmission fluid every 10,000 miles because the transmission cooks the fluid. Eight dollars with of fluid every 10,000 miles. Is that such a big deal?

In my case - a potentially troubleprone 1991 LS400 power steering system - I have learned to periodically clean two filters in the system and periodically change the fluid in the system to prevent future trouble even though this maintenance service is not required or mentioned in the owners manual. I don't consider this extra service a big deal in relation to all the good the car has to offer.

[wwest]

I don't think changing the fluid more often will be an effective effort.

The fluid is being "cooked" because something within the transmssion is over-heating. My guess is that that "something" is the bands and clutch surfaces because they are still not fully engaged as the engine builds RPMs and torque when the gas pedal is unexpectedly(***) and agressively depressed.

***The firmware in the transmission ECU is not downshifting from 3rd(?) to first until the vehicle comes to a full and complete stop. Accelerating just before coming to a full stops results in the need to quickly shift from 3rd(?) to 1st, all while the engine is already reacting to a (fully?) open throttle valve.

Except in the 04 or later with an e-throttle. In that case the engine ECU chooses not to "see" the open(ing) throttle until the transmission has shifted into 1st and the bands and clutches are fully seated. That very like takes more than 1.2 seconds, the time the shop manual says it take to shift from neutral when you first move the shifter to D, drive.

Same problem with/during coastdown, the RX transmission upshifts from 3rd to 4th (according to the 01 AWD Lexus shop manual) during coastdown, and now if you suddenlyn decide to accelerate the transmission must quickly shift from 4th to 3rd, or maybe even to 2nd, and while the engine is already building torque....

Except on the 04 or later models with e-throttle.

So changing the fluid will not delay the premature failure of the bands and clutches.

[jbarhorst2]

Fluid that is no longer beneficial (burnt, dirty) accelerates the wear on any transmission, not just this one.

Keeping fresh fluid in the tranny will surely slow the deterioration of the clutch packs.

The fresher the fluid, the better protected the transmission will be. I don't believe anyone can say that changing the fluid more often causes any failure issues. That is, of course, barring any moronic moves on our part.

[wwest]

"will surely slow the deterioration of the clutch packs..."

It seems to me that were it possible to do so it would be desireable to keep the (lubricating) fluid away from the band and clutch pack friction surfaces altogether.

So how do you figure this?

[jbarhorst2]

Clutches in transmissions are sacrificial. (Yes, I know that the clutch is not "in" a manual transmission)

It is their nature to wear. The fluid helps to slow this process and the better the fluid, the slower the process.

[LexKid630]

hi i have been interested in the rx300 models and am wondering if i should purchase a used one. I was thinking of buying a used 2001 AWD rx300 from my aunt this spring. It has under 42,000 miles on it, has been serviced with the dealer its whole life, and is in good "looking" condition. I am interseted in buying a used Lexus because i want the reliability of a toyota and the looks of a Lexus. I would buy it from her in an instant but don't want to have any major 4400 dollar fixes for a bad transmission after ever so many miles. Do you think it's safe for me to buy the 2001 rx ? Or should i just go out nd spend the same thing for a new Toyota highlander for the same price knowing it wont be breaking soon (with the loss of the looks of a rx300).

Also i cant say that my aunt's the best driver in the world so i'm having more than a few second thoughts. She's one of those "0-60 in under 8" drivers who like to floor it right away. Think this will have a greater effect on the trany problems?

Thanks, Chris

[monarch]

Don't buy any car that has been driven abusively like that. Granny & Grandpa driven used cars have hardly any mechanical wear and tear because they were gently driven

If I was in your shoes, I'd shop for a Granny & Grandpa driven 2WD RX300 because they don't have transmission durability issues like the AWD models do. Put a set of Bridgestone Blizzak WS50 snow tires on the car in winter to get the traction an AWD model provides.

[wwest]

You're kidding me, right..??!!

The frictional surfaces on your automatic transmission's clutches and bands are there for the very same purpose, reason, as the frictional surfaces on your brake pads.

And just like with your brake pads, lubrication will/does promote slippage. This lubricating aspect is overcome by the very high level of fluid pressure used to force them into contact and the quickness with which this contact is accomplished.

Transmission fluid is formulated to provide lubrication and cooling to/for the metal/mechanical components, and as a hydraulic fluid that when pressurized is used to operate the various actuators within the transmission.

And yes, those surfaces are sacrificial, but on the scale of 100,000 or more miles before becoming fully "sacrificed". 153,000 so far on my 92 LS.

[LexKid630]

If lexus found out that the transmissions on the early rx300 models were having serious issues, why didn't they change the problem for the later models like on the 2002 - 2003? and why do the new rx330's still have a problem...

[RX in NC]

Re-engineering and repair rollout is very expensive, and most manufacturers prefer to handle issues such as this on a case-by-case basis until either 1) enough owners document similar problems and demand a solution which eventually forces a TSB or recall or 2) the government steps in and mandates that the manufacturer address the problem to the consumers via a recall. With the mounting RX AWD transmission problem reports across the U.S. and Canada, we owners may well be on the way to 1) above. Only time will tell.

[LexKid630]

you'd think Lexus would care about it's customers a little more...

[monarch]

You're kidding me, right..??!!

The frictional surfaces on your automatic transmission's clutches and bands are there for the very same purpose, reason, as the frictional surfaces on your brake pads.

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The friction surfaces of a dry (unlubricated) clutch like a manual transmission clutch are huge in size and thickness. An unlubricated clutch must be huge to last.

The friction surfaces of a wet (lubricated) clutch like those inside an automatic transmission are small (fit in the palm of your hand) and thin (less than 1/8 inch thick). They will last 200,000 - 500,000 miles if and only if they are properly lubricated and cooled by clean, unburnt automatic transmission fluid.

Toyota / Lexus car transmissions have not had bands since 1976.

[ColinBarber]

If lexus found out that the transmissions on the early rx300 models were having serious issues, why didn't they change the problem for the later models like on the 2002 - 2003? and why do the new rx330's still have a problem...

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RX330 transmission problems are slow downshifting and jerky changes at low speed, nothing to do with early failures or burnt fluid.

[monarch]

you'd think Lexus would care about it's customers a little more...

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The door swings open both ways: Lexus could say "customers should care about their cars a little more and be willing to change the inexpensive auto trans fluid every 10,000 miles because the AWD transmission tends to overheat the fluid."

And Lexus could say: "If we spent 50 billion dollars replacing and reengineering 300,000 AWD transmissions to make them run cooler it would be a monumental waste of time, money and resources as compared to the simple, inexpensive individual owner solution of replacing the transmission fluid more often."

[wwest]

Earlier RX300 burnt fluid and transmission failures and RX330 hesitation problems are directly related, ABSOLUTELY.

Neither Lexus nor Toyota can announce a fix nor explain the cause without admitting that FWD vehicles are potentially hazardous in certain slippery roadbed conditions.

The RX300 series is burning the fluid and the transmissions are failing prematurely because the transmissions are being upshifted during coastdown and/or when coming to a complete stop to prevent loss of control resulting from front wheel engine braking.

When the driver suddenly changes his or her mind about continuing the coastdown, or not actually coming to a complete full stop, and applies a serious level of open throttle the transmission must be quickly shifted into the proper, lower, gear. The engine is already building revs and torque and the transmission downshift will undoubtedly result in a seriosu level of slippage between the clutch's frictional surfaces. Enough times in 40k miles and the fluid is now burnt enough to be not fully functional as was the origainal formulation.

With the advent of the use of the e-throttle in the 04 and later series Toyota and Lexus simply choose to delay the onset of engine revs and torque until the transmission downshifts into the appropriate gear and the clutches can be firmly seated.

The Lexus shop manual for the 01 RX300 indicates that the transmission torque converter lockup is disabled any time the brakes are applied, significantly reducing engine braking. And during coastdown the shift pattern indicates an upshift from 3rd to 4th. Under just what circumstances would that latter move be appropriate other than removing the effects of engine compression braking?

Owners of the RX330 who are experiencing the hesitation problem can likely overcome it by just slightly opening the throttle for a second or so before aggressively doing so.