Rx300 Awd Transaxle Failures

[wwest]

----- Original Message -----

To: <Customer_Satisfaction_Inquiries@lexus.com>

Sent: Friday, June 03, 2005 9:05 PM

Subject: ATF

> Dear Sirs,

>

> In the process of trying to decide whether or not to upgrade, trade my 2001

> AWD RX300, for/to the 2006 AWD RX330 I have recently purchased the RX330

> repair manuals and the 2005 RX330 owners manual.

>

> On page 83, right hand column, of the 2005 RX330 owners manual there is an

> indication that the ATF in the transaxle of the AWD models of the 2005 RX330

> is subject to overheating. The statement clearly implies that continued

> operation with overheated ATF may result in permanent damage to the

> transaxle.

>

> Previously I have brought to your attention to the fact that the ATF in my

> 2001 AWD RX330 appeared inordinately dark and smelled burnt at only 38,000

> miles. You advised me to check with the dealer for a solution and I was

> advised by Bellevue Lexus to drain and replenish my ATF each 15,000 miles.

>

> My 2001 AWD RX300 came equipped with the towing package, extra ATF cooling heat exchanger in front of the right front wheel well, but I removed the

> hitch the very week I purchased the vehicle, new, from Bellevue Lexus. In so far as scheduled maintenance is concerned until I was advised otherwise by

> Bellevue Lexus I understood the ATF did not require any scheduled

> maintenance for the life of the vehicle.

>

> At 45,000 miles the ATF was again dark and smelled burned so I changed it

> out once again. About a week or so later I checked the ATF condition (slow

> learner) and again found it dirty. I then inadvertently discovered that the

> front & center differential case needed to be drained separately, resulting

> in the need to refill with 5 qts of ATF instead of the four insisted upon by

> Bellevue Lexus.

>

> Additionally I have noted on the internet that seemingly the RX300

> transaxles are subject to premature failures at 60,000 to 75,000 miles.

>

> And now I discover that the RX330 series, AWD models ONLY, are subject to

> ATF overheating such that a sensor and warning indication is provided to

> announce to the owner when and if the vehicle must be parked long enough for

> the fluid to cool.

>

> Since my 2001 RX300 already has a thermistor within the transaxle sump pan

> to measure ATF temperature should I consider adding an over-temp sensing

> circuit and if so at what temperature, sensor output voltage, should the

> warning alarm be set?

Any AWD RX330 owners out there encountered this ATF overtemp warning

and if so under what conditions?

[RX in NC]

Please keep us posted on Lexus corporate's response to your e-mail.

Based upon your transmission experiences with your 2001 model, I am surprised and puzzled that you would consider purchasing another RX.

[wwest]

I purchased Fords for many years mostly because I knew them inside and out. IMMHO Lexus is the top of the heap and all marques have their problems.

Plus I'm a quite throughly addicted shade-tree mechanic.

[VGR]

What other car maker consistently builds transmissions and engines that last 300,000 - 600,000 miles? We have not heard of any RX300 AWD transmission failure if the owner had changed the fluid every 15,000 miles since the time the vehicle was new. Therefore it's possible the RX300 AWD transmission is capable of lasting 300,000 miles if the owner changes the fluid frequently.

Same situation with the V6 engine of the '99- '02 RX300 and '97-'02 Toyota models. Some V6 owners who changed the oil every 3-6 months or 3000 - 6000 miles

have now accumulated 300,000 troublefree miles. But some V6 owners who extended oil changes ended up with sludge and a ruined engines in as little as 30,000 miles.

Many of the owners who got sludge consider themselves "victums" and have vowed "I'll never buy another Toyota / Lexus product again". Which means they just talked themselves out of buying another 300,000 - 600,000 mile capable vehicle.

An alternative attitude is: "I'll buy another Toyota / Lexus product, but this time with the understanding that while all Toyota engines / transmissions have historically been capable of lasting 300,000 - 600,000 miles, some will likely require more frequent lube changes than others to be that durable. Since it is impossible to know ahead of time which ones may need more lube changes, I'll simply play it safe and change the lubes frequently anyway."

[wwest]

The service manager at Bellevue Lexus informed me recently that Lexus had come down on them rather hard for selling services that are not needed. To that end he said the new information is to inspect the transaxle fluid at each 15,000 miles interval and only change it out if it appeared necessary.

I have owned too many cars with automatic transmissions, mostly Fords, that didn't require ATF service for over 100,000 miles to rethink that Lexus was wrong when there was no maintenance required for the life of the vehicle for my 2001 RX300.

Obviously there is no harm, other than to your wallet or the increased opportunity, possibility, that a "gofer" will screw up, in changing the ATF every 15,000 miles but to make it required means something has gone wrong in the base design.

Page 564 of the 2005 RX330 owners manual:

"* Change automatic transmission fluid only as necessary. Generally, it is necessary to change automatic transmission fluid only if your vehicle is driven under one of the Special Operating Conditions listed in your owners manual..."

[VGR]

Obviously there is no harm, other than to your wallet or the increased opportunity, possibility, that a "gofer" will screw up, in changing the ATF every 15,000 miles but to make it required means something has gone wrong in the base design. Page 564 of the 2005 RX330 owners manual:"* Change automatic transmission fluid only as necessary. Generally, it is necessary to change automatic transmission fluid only if your vehicle is driven under one of the Special Operating Conditions listed in your owners manual..."

←

In the 60's the owners manuals of nearly every car maker, including Toyota, specified auto tranny fluid changes every 12,000 - 18,000 miles. Owners who followed that advice routinely got 200,000 and even sometimes 300,000 - 375, 000 miles of troublefree transmission service. Owners in those days did not view these frequent oil change requirements as evidence of "a weak design."

After having the fluid changed every 15K, RX300 AWD owners can recheck the fluid level themselves if they want to be sure a "gofer" didn't screw up.

There's no evidence (so far as I'm aware) the transmission design of the AWD RX300 is bad, only that fluid cooling is not real good, hence the need to change the fluid more often. For legal / product liability reasons I don't think its reasonable to think Corporate Lexus (or corporate of any other car maker) would ever be willing to admit anything is wrong or weak with their transmissions. Hence owners either have to do something to compensate for a known weakness such as fluid cooling (by changing fluid more often) or face the potential consequences (premature tranny failure).

The owner' manual statement: "Change automatic transmission fluid only as necessary" is contingent on regular inspections of fluid condition and it appears alot of owners don't realize that. In any case, corporate Lexus has no objection to owners who wish to change their fluid regularly anyway for peace of mind reasons.

[wwest]

"..contingent on regular inspections..."

NOT!

When Toyota or Lexus deem that regular inspections are needed they do not hesitate to so state!

Read the owners manual section on maintenance if you do not believe me.

And, being now 64 years of age, I happened to be around in the early sixties and I can assure you that Toyota was not, at least not in my part of the US.

In any case the 1968 Ford country squire station wagon I bought new was retired to the wrecking yard with 268,000 miles on the odometer. I had personally overhauled the engine and automatic transmission at somewhere about 125,000 miles because the bands were worn out.

Insofar as I know that was the one and only time the ATF was changed out.

My next Ford, another country squire station wagon, a 1975, also went for over 200,000 miles before my daughter managed to total it out. With that one I got lazy and bought a used transmission, 30,000 miles, from a wrecking yard to swap in when the original's bands begin to slip at about 125,000 miles.

I can "point" you to not less than 5 LS400s, 92 up to 95, that now have over 100,000 miles and none of them have ever had the ATF changed out. Nor have they needed it.

I have always been quite conscientous about properly maintaining all of the vehicles I have owned, or own, so while I do not today remember what the Ford owners manual said about this I am quite comfortable taht had it required ATF change outs that's what I would have been doing.

[wwest]

The chicken or the egg question..

Is the ATF fluid overheating due to insufficient cooling capability or is the overheating the result of the fluid being inordiantely contaminated with frictional surface wear debris as the result of a poor or improper design?

The AWD model of the 2005 RX330 has an ATF overtemp indicator light and if it illuminates the driver is cautioned to pull to the side of the road and allow the ATF to cool before proceeding.

Since my 2001 is AWD I suspect it to be subject to the same design flaw that results in the possibility of the ATF overheating in the 2005. Additionally mine has a viscous coupling within the PTO which would no doubt contribute additional heating to the ATF within the adjacent diff'l and transaxle.

[RX in NC]

wwest,

I tend to agree with your theories about why the RX300 AWD transmissions fail prematurely even when meticulously maintained by the owner. VGR can't seem to comprehend that the owners manual and the dealership service departments are on opposite and conflicting sides of the spectrum regarding what constitutes proper transmission maintenance for this particular vehicle. Whether that is for valid design flaw reasons (which gets my vote) or customer rip-off reasons (generating greater revenue with what your owners manual says is an unnecessary service) is inconsequential.

[VGR]

VGR can't seem to comprehend that the owners manual and the dealership service departments are on opposite and conflicting sides of the spectrum regarding what constitutes proper transmission maintenance for this particular vehicle.

←

VGR has no problem understanding that all car makers and engineers and dealership service departments agree that any automatic transmission will be more reliable and last longer if always lubricated by clean, unburnt transmission fluid.

VGR has no problem understanding that the transmission service frequency intervals listed in car owners manuals are actually just the MINIMUM ALLOWABLE intervals required to keep the powertrain warranty in effect; they are not the optimum intervals required for the owner to achieve maximum transmission reliability and durability.

VGR has no problem understanding that for at least 30 years, all car makers who operate in the USA are under heavy consumer marketing pressure to produce cars that require a minimum amount of componet maintenance. Hence, sometimes car makers push the minimum service frequency envelope too far, resulting in componet failures soon after the powertrain warranty has expired.

Now in some other countries such as Australia, Brazil and Saudi Arabia to name a few, this consumer marketing pressure to produce a minimum maintenance car is substantially reduced and therefore Toyota and other car makers operating in these other countries freely publish shorter component service interval without fear that it will adversely affect car sales.

[wwest]

If the MINIMUM ALLOWABLE period is infinity (life of the vehicle) then what is the optimum interval required for the owner to achieve maximum transmission reliability and durability?

It is quite well proven, and accepted within the engineering community, that a properly designed automatic transmission will not overheat its lubricating fluid, absent abuse, during its usefull design life.

[sgriffith]

Furthermore, if the MINIMUL ALLOWABLE interval is what they are recommending, then it should be enough to at least keep everything functioning properly inside of the vehicle. If their design engineers designed the RX so well inside and out, and they are the same ones suggesting the service intervals in the book, then there should be no problems. Every 15K is absurd....and I do it!!!! I am so sick of worrying about my RX that I am going to sell it within the next 5K miles because my extended warranty will be out. I am sick of things going wrong with this vehicle. I am not at all putting down ALL of the toyota/lexus designs...because I am probably going to buy a 2001 LX that my friend is about to sell....but I will not buy another RX. It is sad because I like the vehicle so much, and really do like the new 330. I would love to buy another one, but won't because of the constant BIG problems.

[jbarhorst2]

My 2001 AWD RX also has an AT Oil Temp light on the dash.

Tom

[mikey00]

I don't think the ATF fluid is overheating due to insufficient cooling capability. If this were the case, the RXs without the cooler (non-tow prep package) should be failing at a much higher rate than the ones with the cooler. I agree the cooler isn't the greatest but it must be a lot better than none. Most RXs with the tow prep package never see a hitch. I believe the failures are being caused by fluid being contaminated with debris as the result of a poor design.

VGR: It's not just the neglected transmissions that are failing.

[wwest]

If you can overlook my red face I will admit that I do have an ATF overtemp indicator on 2001 AWD RX300. I went out and checked to see if it came on with the ignition switch as soon as I saw jbarhorst2's post.

It does.

But that means that in 45,000 miles it has never come on (I like to think I would have noticed) and so by Lexus' standards it has NEVER overheated.

[jbarhorst2]

FYI....

The center differential takes the same gear oil as the rear diff. It does not take the same fluid as the tranny.

Tom

[RX in NC]

jbarhorst2,

I'm not sure what you mean by the "center differential", but the "front differential" (which is located just behind the transmission pan) not only uses Type T-IV transmission fluid, it also obtains its fluid from the main supply inside the transmission pan. Whenever you drain-and-fill your transmission pan, you should also drain the "front differential". Both are then filled with fresh fluid through the transmission dipstick tube.

The drain plug on the "front differential" is identical to the drain plug on the transmission pan except the "front differential" drain plug has a magnet on its inside tip in order to catch and hold any metallic particles that may shed and be suspended in the fluid during the course of operation. Be sure to clean this magnet thoroughly with a rag before !Removed! the drain plug back into its housing.

Both the transmission pan drain plug and the "front differential" drain plug are removed and replaced using a 10 mm hex wrench (also called an Allen wrench).

I researched this topic very thoroughly last autumn and I know that this information is accurate for the RX300 series. I change my own fluids and can confirm that everything I've stated above is 100% correct. I'm not sure about how many differences may be involved with the RX330 series, however.

[capt nemo]

I don't think the ATF fluid is overheating due to insufficient cooling capability. If this were the case, the RXs without the cooler (non-tow prep package) should be failing at a much higher rate than the ones with the cooler. I agree the cooler isn't the greatest but it must be a lot better than none. Most RXs with the tow prep package never see a hitch. I believe the failures are being caused by fluid being contaminated with debris as the result of a poor design.

VGR:  It's not just the neglected transmissions that are failing.

←

[capt nemo]

I don't think the ATF fluid is overheating due to insufficient cooling capability. If this were the case, the RXs without the cooler (non-tow prep package) should be failing at a much higher rate than the ones with the cooler. I agree the cooler isn't the greatest but it must be a lot better than none. Most RXs with the tow prep package never see a hitch. I believe the failures are being caused by fluid being contaminated with debris as the result of a poor design.

VGR:  It's not just the neglected transmissions that are failing.

←

←

[capt nemo]

My experience has been, that if you want your transmission to last, buy a good aftermarket cooler, even if you don't tow. I got 150k on a lincoln and 100k on a jag, before i sold the cars (kept the cooler)

Also my transmission guy told me some time ago, that if you want superior transmission fluid buy (either synthetic or silicon; can't remember which) do remember that it was expensive. I had never heard of it and never pursed it..............for what its worth!

[wwest]

The AWD rear PTO, Power Take Off, case is in line with the right front drive halfshaft and is attached to the right side of the diff'l (front and center) case. PTO uses gear oil, diff'l runs in ATF.

[lenore]

The AWD rear PTO, Power Take Off, case is in line with the right front drive halfshaft and is attached to the right side of the diff'l (front and center) case. PTO uses gear oil, diff'l runs in ATF.

←

What you say is true, The PTO uses different fluid. I have spent a great deal of time giving my plight in the transmission failure business. I am on my third transmission which I have changed the fluid at 10k miles. My warranty is due sometime in August or September, dependent on the 2nd or 3rd tranny change. At that time I am going to add a Filter (external) and possibly relocate the tow package transmission. Lexus is the most unresponsive, and lowest customer care organization I have ever dealt with. The Japanese should come in and fire all of the American corporate leaders. They are no better than a bunch of self centered theives. From overchargeing on plastic keys, to transmissions that should have not failed they back nothing. I too have worked on cars most my life, and would never have believed the failure of a transmission at 60 to 100k on a automatic. Chrysler, yes, but a luxuary car come on. I filled out my consummers report survey to support this rediculous support. And by the way I did something I never dreamed I would do bought my first American vehicle, instead of a Tundra a Ford.

I figured at least a do it your self person like me would at least get the parts cheaper. I feel sorry for anybody that buys a RX300 and drives it in normal commute traffic. I do not tow, and the %$^#@ thing failed not once, but twice, and the dealer has done work more appropriate to a shade tree mechanic. My storey is long, but follow the trail of the number of hits and failures by others like myself. $4600 later and I am scared to go anywhere that AAA is not available. I hope that most of you do not experience the arrogant attitude that I received from Lexus of America. Thank you.

[lsrxlex]

My experience has been, that if you want your transmission to last, buy a good aftermarket cooler, even if you don't tow. I got 150k on a lincoln and 100k on a jag, before i sold the cars (kept the cooler)

Also my transmission guy told me some time ago, that if you want superior transmission fluid buy (either synthetic or silicon; can't remember which) do remember that it was expensive. I had never heard of it and never pursed it..............for what its worth!

←

What brand did you use and where to buy the cooler for the 1999 RX300?

Thanks.

[wwest]

Quality of a shade tree mechanic.......!!!

I'm insulted, VERY!

[SKperformance]

Here is a tip

Your transmission needs heat to work properly.

So having it at 150F is good not bad ,over 200 gets a little hairy.

My cousin who runs a tranny rebuild shop is against selling me a cooler as it can take a tranny longer to get to temp with it, as well as it is not needed when a car is moving only when their is not enough air flow over the original cooler lines on the tranny will it creep up in temp.

I have a transmission temp gauge fitted to my car for my personal interest of it.

What i did find is by turning the A/C on when in slow moving hot traffic i drop my temp by 30 degrees by having the fan continously on.

This makes a external cooler redundant as it has no extra cooling properties in crawling traffic.

If i keep the a/c on before it gets very hot it will keep my temp at 150 instead of creeping to 220 and only will go down to 180 if used after with the a/c.

So an easy way to gain extended life from the tranny and fluid is to use the a/c whenever in slow moving traffic to keep temps down.

Add an external tranny filter also will be one of the best 2 things that should keep the tranny going for alot longer to tackle the stupid metal mesh that can't filter anything but large particles and then clog.