Rx300 Auto Transmission Fluid, When to change?

[bluestu]

If what you're saying is true, why drain and fill the transmission at all? I realize that in a standard transmission you can pull the plug, remove the pan and just about all the fluid drains out. Replace the filter, refill and you're ready to go. A RX300 transaxle is a different story and would have to require a different procedure. If the designers were so brilliant in their maintenance recommendations, then why are so many RX owners complaining about transmission failure and dirty fluid? Putting total trust in design teams and engineers may be OK for some, but considering the huge number of design flaws made by the auto industry through the years, I lean more towards making my own educated decisions and trusting the advice of reputable, qualified mechanics. I'll be getting a transmission flush on my RX300 every 30k miles.

[jgr7]

Thats my point there must be something going on to make the oil get dirty so fast. My guess would be a cooling issue. Lexus recommends 100k right? So they must think the same way as the gm guys however something is not right if trans fluid is getting burnt and/or dirty at less than 30k. I will be changing my fluid every 30k as insurance, just the pan oil though and never a flush. If my oil smelled burnt I would go for total replacement but not a flush. My 94 Eldorado went 100k before change, this car was driven hard and fast, there has to be something causing burnt or dirty oil in the low mileage lexus transmissions.

Has any one tried an external cooler other than the factory one?

One would think that if it was a complete design flaw there would be so many failures that a recall would be in order. I'll have to drive my rx more and see if I can feel anything happening with the trans that doesn't feel right, this might be hard to do though as it is hard to get it away from my wife.

Jeff

[RX in NC]

What I think we all can agree on is that the RX transmission, particular AWD, is problematic and may very well suffer from design flaws or faulty components or both. As a minimum, do a drain-and-fill with clean T-IV fluid every 30,000 miles. If you trust your local shop and their equipment, then do a flush at 30,000 miles, and bring your own T-IV fluid. But if you do choose to flush, understand that your contaminant risk factor will increase. How much? No one can say, it will depend on the shop, the equipment, and the skill of the mechanic doing your flush.

I'm going to stay with my drain-and-fill procedure for as long as we own this RX. I'll keep all receipts and documentation as I do this myself. That will be more than enough proof if I have to battle Lexus for still another new (rebuilt) transmission. And finally at about 130,000 miles, we'll say goodbye to this RX and move back to a vehicle with a more tested and bulletproof transmission.

[SW03ES]

That might be an interesting idea to try an auxilliary tranny cooler...

[bluestu]

RX In NC,

I am not in agreement with you on this issue. You did say the transmission on your RX fried up after 70k miles and all you ever did to maintain it was a drain and fill. To me, that's more proof that a drain and fill is not sufficient for proper maintenance.

Both of my RX300s have almost 80k miles and shift very smoothly, and I don't notice any jerking or shifting delays. The fluid is extremely clean and does not overheat. Maybe I'm just lucky, but I don't think so. You are the lucky one, seeing as how you were able to persuade Lexus into replacing your transmission after your warranty had expired. I guess persistence can pay off for some, but for most of us, it would be a costly venture.

[RX in NC]

bluestu,

You've got the facts wrong about my particular RX. The transmission never "fried up", it had a quirky tendency to disengage for a couple of seconds at unpredictable times. My wife judged it to be dangerous, and I agreed with her. That's why I battled Lexus for a replacement.

This occured last November at just over 48,000 miles while the vehicle was still under the normal Lexus warranty.

You trust your flush provider, and that's good news for you. But there are a lot of unknowledgable owners out there who wouldn't do the research, take their vehicle into a Jiffy Lube or other one-size-fits-all chain, and wind up getting a flush with generic fluid that will do far greater damage to the vehicle than doing a drain-and-fill themselves with T-IV fluid.

You've got to be careful out there with these RX transmissions. All I'm saying is you'd better be sure that you trust your flush provider 100% before you hand him your car keys or your transmission will wind up in worse shape than when you drove in.

[eric618]

Is it possible to drain and flush the system at home? i.e. through the transmission cooler lines? I would think the old fluid could be purged while recirculating fresh T-IV fluid until it runs clean. That way there is less margin for error OR contamination.

Thanks!

[legg1042]

I have a question for anyone who will answer. About a month ago, I was out of town and my wife had the trans. fluid changed. This weekend, less than 1000 miles later, we were taking her mother home, about 2 hours away. The rx started jerking a little, and when we got to a stop light, it would not go, only rev up. I shut the car off for about 5 minutes, and started it back up and moved to a safer part of town, (about a mile) where it started doing it again. The next morning I had it towed to the local dealership where they want to give me a reman trans. The people I've talked to in my office think it might be more simple than a completely new trans. I don't know exactly what to do. Any suggestions will be extremely helpful. 1999 RX 300 AWD.

[RX in NC]

Who changed the transmission fluid? If anything other than Toyota Type T-IV transmission fluid went into your transmission, you're going to be in a world of hurt.

[wwest]

Much more likely some Lexus gofer, graduate from McD university, drained the transmission fluid and then forgot to add some back in.

[wendell]

16 qts!? Are you sure? The old fluid in my car is black and a little thick. 4 qts of new fluid is not enough then. I don't want to flush it (bcs I heard bad news on flushing). I may need to drain it in a few days again. Right?

←

I'm positively sure. I just had mine flushed about a month ago and the fluid looks like new, pinkish in color. I did some pretty extensive research on this matter and found that the only way to completely change the transmission fluid is to have it flushed. Not only does this completely replace the existing fluid, but also cleans the wire mesh filter inside the transmission. Make sure you replace the fluid with the right type of fluid which is clearly marked at the top of the dipstick. You should also have your differential and transfer case gear oil drained and replaced every 30k mi.

The reason your transmission fluid looks dark is because you've just been having a portion of the fluid drained out and new fluid added. The new fluid just mixes in with the dirty fluid, so your fluid just keeps getting dirtier and dirtier. Any qualified mechanic will tell you that the drain and fill performed by Lexus and Toyota is useless and a waste of money. I take my cars to a place called Mostly Toyotas and they say that they haven't had any problems with the cars they have flushed. They 100%, absolutely recommend flushing the transmission every 30kmi.

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Iam one of these idiots that know nothing about engines(electronics guy), well a little bit. I went to one of these transmission places and replaced it there(9k+ miles ago). I don't know if they used the "toyota IV fluid" that you guys recommended, will this cause any problems in the long run.... or all transmission all the same? Should I get it redone?

Thanks

[ColinBarber]

It will cause problems if T-IV wasn't used. Some people notice problems very quickly afterwards so hopefully the correct fluid was used in your case.

[velk]

I've read the RX transmission topic and noticed that two people had their transmissions failed after the fluid was changed at the dealer!

I would follow the owners manual and take my chances driving with the factory fill.

[RX in NC]

You simply must change the T-IV fluid on a periodic basis. The transmission cannot survive if you attempt to run it forever on the original factory fluid. Transmission fluid, like motor oil, wears out and breaks down over time, although not nearly as fast. It also accumulates the tiny metal particles created as your gears slowly wear down from normal driving conditions.

I changed my wife's vehicle's transmission fluid this past Saturday. The differential drain plug, which has a magnet attached to its underside, did its job by attracting the metal-based "gunk" created by driving. I wiped and polished it to a mirrorlike condition before I replaced it along with the regular transmission pan drain plug and then filled the system with new T-IV fluid. Based on our experiences with this vehicle, I'll do this every 30,000 miles for as long as we keep it. Some folks decide to do this every 15,000 miles. Either way, you have to change your fluid. Don't be fooled into thinking that it lasts for the life of the vehicle. Until gears are created that never wear down, there will be debris and breakdown in all vehicles' transmission fluid.

[SKperformance]

Get an external filter as tthe metal mesh is insufficent

then get a flush, clean the mesh and you will be perfect

[artinist]

i am one of those people who had a transmission failure.

those cases where the car stops and just revs are due to the strainer clogging with metal flakes and no oil pressure gets to the tranny.

the oil is no big deal i have found. the type T 4 is not really any different than the regular dextron III. its just their way of their continious rip off.

i talked to several tranny shops about this and they all said they use regular dexron III all day in these and they wouldn't do it if they wanted to stay in business and give a 12 month warranty.

my problem actually started shortly after I changed the oil without dropping the pan. and yes i did use toyota oil.

my mechanic had an inside contact with the service center who services and certifies these transmissions. supposedly my new tranny does not suffer from the flaw that makes these things break so quickly.

as for the oil change, never ever change the oil without dropping the pan and changing the filter.

yes, there supposedly is no filter in this tranny but thats BS. there is a metal mesh strainer that has to come off and cleaned.

actually this screen has been upgraded by a new filter design with a fabric material.

its around $20 for the new filter and droping the pan will let you know whats going on inside the tranny.

[lenore]

RX In NC,

I am not in agreement with you on this issue. You did say the transmission on your RX fried up after 70k miles and all you ever did to maintain it was a drain and fill. To me, that's more proof that a drain and fill is not sufficient for proper maintenance.

Both of my RX300s have almost 80k miles and shift very smoothly, and I don't notice any jerking or shifting delays. The fluid is extremely clean and does not overheat. Maybe I'm just lucky, but I don't think so. You are the lucky one, seeing as how you were able to persuade Lexus into replacing your transmission after your warranty had expired. I guess persistence can pay off for some, but for most of us, it would be a costly venture.

←

When my transmission failed there was no warning signs, It just lost overdrive and fourth gear. Drove great the day before and just died. We really need to challenge Lexus of America to step up to the probablity of poor cooling especially in heavy commute traffic with very little cooling on the fender/wheel well coolor.

[velk]

I just did some statistics from the posts in this thread: 4 different people had their trannies failed shortly after the oil change. Something is going wrong with these transmissions when the oil is drained and refilled.

quotes:

lenore: My transmission failed july 8,2004 and I serviced it every 30k miles.

artinist: my problem actually started shortly after I changed the oil without dropping the pan. and yes i did use toyota oil.

legg1042: About a month ago, I was out of town and my wife had the trans. fluid changed. This weekend, less than 1000 miles later, we were taking her mother home, about 2 hours away. The rx started jerking a little, and when we got to a stop light, it would not go, only rev up. I shut the car off for about 5 minutes, and started it back up and moved to a safer part of town, (about a mile) where it started doing it again. The next morning I had it towed to the local dealership where they want to give me a reman trans.

rbrown2769: I just replaced the transmission in my 99 RX300 and I had my fluid changed at 75,000 mile service interval. It failed at about 78,000.

[wwest]

First of all....

OIL does NOT wear out!

Neither engine lubricating oil nor transmission hydraulic fluid.

The primary reason you change your engine lubricating oil is because it becomes contaminated by the by-products of combustion. Before changing my engine oil I run the car to the point where it is up to temperature. That allows the oil to pick up and hold in suspension most of the particles that have settled into the sump.

Engine oil can, and often is, recycled many times and reused. Most dealers, even Lexus, buy recycled engine oil in bulk in order to cut

costs.

Transmission oil is more in the nature of hydraulic fluid than it is for lubrication. Transmission fluid is formulated specifically to allow particles to settle out of the oil and into the sump, as it would be detrimental to the long term reliability for it to hold then in suspension.

For the person who had a filter clogged with metalic particlles my guess would be that you are looking at more problems soon down the road.

The primary source of debris of this type is the result of wearing of the clutches and bands, material very much like that of your brake pads.

I can't even estimate how many miles I have driven since 1961 without ever having changed or flushed transmission fluid absent work on the transmissions. Work that was mostly overhauls at 100K plus.

[jgr7]

I agree with wwest, trans fluid is in a closed system and unless there is some kind of event that has happened to the trans, like over heating, towing a trailer or something causing a pressure drop that would lead to slipping. Trans fluid should and does last into the 100ks on many cars. I hate to keep going back to my Cadillac that I traded in on the RX, but those have a Northstar with 300hp, front drive a 4T80E automatic trans and it goes 100k+ on the fluid change. Many of the 4T80E failures that I have heard about were reported within a few thousand miles of having a trans flush.

I haven't seen any stats on how many trans failures Lexus as well as Toyota have had on these transmissions. And I know that there are some members here that have had failures, but man I sure see a whole lot of these cars running around and haven't heard of any recalls. It may be just the luck of the draw.

Jeff

[RX in NC]

Yes, transmission fluid seems to last far longer and present fewer problems in many domestic vehicles. The three Jeep Grand Cherokees we've had all went well beyond 60,000 miles before the fluid began showing signs of particle accumulation and needed to be changed. I did so without any follow-up problems whatsoever. My 1999 Dodge Ram 1500-series 5.9-litre V-8 pick-up currently has about 37,600 miles on it and the transmission fluid is still sparkling clean. But these Lexus RX300s simply don't retain clean fluid for nearly as long for whatever reason. Perhaps the clutches and bands are too soft. Perhaps the gears aren't as solid. But whatever the reason, there appears to be a much higher number of failures of these transmissions. So if you own an RX and choose to run the factory transmission fluid fill for the life of your vehicle, many of us would say that you're rolling the dice and playing with fire.

[lenore]

Yes, transmission fluid seems to last far longer and present fewer problems in many domestic vehicles.  The three Jeep Grand Cherokees we've had all went well beyond 60,000 miles before the fluid began showing signs of particle accumulation and needed to be changed.  I did so without any follow-up problems whatsoever.  My 1999 Dodge Ram 1500-series 5.9-litre V-8 pick-up currently has about 37,600 miles on it and the transmission fluid is still sparkling clean.  But these Lexus RX300s simply don't retain clean fluid for nearly as long for whatever reason.  Perhaps the clutches and bands are too soft.  Perhaps the gears aren't as solid.  But whatever the reason, there appears to be a much higher number of failures of these transmissions.  So if you own an RX and choose to run the factory transmission fluid fill for the life of your vehicle, many of us would say that you're rolling the dice and playing with fire.

←

Again I feel the major problem is cooling, my wifes car is commuted on back streets for most of the distance of 14 miles one way. The cooler is not located as most coolers in the radiator or infront of the air stream of the radiator. the cooler is located in the right front wheel wheel behind the bumper. there is a access hole but it is partially blocked by the windshield washer resevoir. and the air exit is very constricted to some slots inside the wheel well. My fluid was always burnt and very black. I changed the filter and dropped the pan on all three 30k fluid changes and found very little debris. Lexus has a cooing issue when the car has not been driven at highway speeds giving the best air flow across the transmission cooler. My car is driven at a 160 feet above sea level and no mountain or hill driving. Accura has addressed their problem with a larger cooler. I noticed no failures of other toyota products but have looked and found the cooler is placed in a more traditional area where air flow is present. I suspect my transmission had a heat failure and lost some gear or clucth pack rings. When it failed and The salt Lake city Lexus dropped the pan they found severe debris in the filter and pan. This was only 7k after a fluid and filter change which showed none, and only the the burnt and black condition exhibited all along. Signed Lenore.

[VGR]

Yes, transmission fluid seems to last far longer and present fewer problems in many domestic vehicles.  The three Jeep Grand Cherokees we've had all went well beyond 60,000 miles before the fluid began showing signs of particle accumulation and needed to be changed.

←

On the other hand, look at all the 4 cylinder automatic transmission Toyota motorhomes on the road. No American car / truck maker builds a 4 cylinder automatic that can hold up hauling around a 6,500 lb motorhome. So I believe Lenore is right - Toyota probably did not engineer enough cooling capacity (for urban driving) in the RX300 transmission.

[lenore]

Yes, transmission fluid seems to last far longer and present fewer problems in many domestic vehicles.  The three Jeep Grand Cherokees we've had all went well beyond 60,000 miles before the fluid began showing signs of particle accumulation and needed to be changed.

←

On the other hand, look at all the 4 cylinder automatic transmission Toyota motorhomes on the road. No American car / truck maker builds a 4 cylinder automatic that can hold up hauling around a 6,500 lb motorhome. So I believe Lenore is right - Toyota probably did not engineer enough cooling capacity (for urban driving) in the RX300 transmission.

←

The fluid in the Lexus fails because of heat failure. I will be adding a cooling fan to the cooler in the wheel well this summer. I am also going to add a transmission filter to eliminate particle failure in the valve body assembly, which when I dropped mine was contaminated with metal debris. This after three transmission fluid changes in 100 k with the filter being changed on each dropping of the oil pan.

I am still under warranty from the third transmission installed last August. Lexus has a design problem and is not willing to back their product or make retrofits to help aleviate the failures. I agree that until you sell the vehicle replace the fluid every 15k miles otherwise face a 4600 dollars replacement and pray that the dealership puts it back together properly. My war saga is well documented. Good luck and keep changing that fluid

[RX in NC]

Yep, my biggest gripe by far with Lexus corporate is the inferior and flawed transmission in the RX300 AWD. For Lexus to claim in the owners manual that the Type T-IV fluid should never be changed during the life of the vehicle under normal operating conditions is pure lunacy and an invitation to disaster.

I've learned my lesson and we'll never own another one as a result.