toyo

The good ole Toyota fluid debate. A little history of my car. I drive a 2001 Rx 300 AWD. I have currently a little over 100k miles on it. I have performed all the maint on it myself. I change the oil and filter [Toyota filter] using Mobile 1 5w30 every 4 k miles since day one. I got a little curious one day as too how the inards looked inside my engine. I dropped the oil pan and it was spotless. Not one hint of sludge or any other substance. I could wipe my finger on any part and it would come back clean, no black satins at all. I was very happy, I do not feel I would have had the same results with regular dino oil.

Now to my transmission service:
I have performed the drain and refill service every 15 k miles since new. It always has a dirty look to it. I would not feel comfy waiting any longer to do such service. I have researched the fluid a couple of times. Nobody has been able to tell me why I can use anything but Toyota fluid. I buy mine in the gallon size at the dealer. I can at least say my trans still shifts like new. I tow my atv's about every other month at the most. The trans always feels good when towing.

If I can give one piece of advice: Change the fluid, no you dont need to do a flush if you stay on top of it.

SeattleGS400

iTrader: (1)

Sure some change their oil religiously every 3K, some at 18K. I just happen to change my engine oil at 4-5K and my ATF around 10K. Maybe overkill on ATF, but it gives me a good piece of mind.

I wonder why Ford did this? Maybe they found the miracle ATF that lasts forever as you hinted or is their transmission significantly superior to all other car manufacturers for them to do this? I wonder about those car owners that drive their cars hard, modify their cars w/ supechargers, tow trailers, or those that just live in a hilly locale? Would you think that the higher ATF temps would cause the ATF (including additive and detergents) to breakdown over time? Wouldn't it need changing--no? Or is it just that Ford was cheap and decided to not put any drain plugs in that transmission or maybe they wanted to design their cars to last until 80K miles, upon which they want you as the consumer to buy a new transmission? Just because Ford sealed their transmission does in no way validate the fact that the ATF will last forever. Most fluids will oxidize over time (unless of course, you begin with an oxidized fluid, then it won't change), some are more resilient than others to oxidation, but given thermal stresses and also pressure cycles, fluids (and their additives) will break down and lose effectiveness over time--not to mention accumulate transmission particles over time from gear teeth engaging/disengaging during shifts.

30K miles/2 years. My manual recommends that as well. Occasionally, I drive my GS400 fast around empty corners or will push it a bit going up hills on the freeway (of course, when no one's around), I know that this will wear down the ATF a bit faster (due to higher ATF temps) than if I was leisurely crusing around town 24-7. I change it at 10k, again, probably overkill, but it's a good piece of mind for my $10 maintenance, like you said. If I was paying $120 per drain and refill, it would be a different story.

From some past discussions, some latest generation Lexus cars (if not all of them) do not have a filter per se. It's more of a mesh screen. It won't filter anyting out that's less than the mesh screen size. If you have a small solid particulates in your ATF, it's going no where unless you drain it out. ATF fluid will do its job in preventing sludge and holding particles in suspension, so long as the additives and detergents work. Once you hit a critical level, they'll need changing. If you don't change the fluid regularly, you'll, of course, get sludge build-up and accelerated wear in your transmission, as the filter (aka mesh screen on our cars) doesn't remove anything from the ATF. Of course, as you mentioned, bypass filtration would help out in removing particulate contamination, but that does not do anything for the degradation of additives and detergents. The only way to get the additive and detergents replaced is to change your ATF.

A new transmission will run about 4K for my GS400 in parts. Add labor and it's probably close to a bit over $5K. Sure rebuilding it at a reputable shop (if you can locate one that doesn't try to scam you in pricing and does quality work), will be a bit lower.

From an economical standpoint, isn't testing the ATF for fluid/chemical analysis cost a bit more than changing the fluid itself? Doesn't it run $12-29 per chemical analysist, depending on where you get it done? Maybe it's just me, but instead of testing the fluid to see if it needs to be changed, why not just change it for a lower cost ($10) and do something that you should have already been doing anyways?

SeattleGS400

iTrader: (1)

Great info--helps validate my use of synthetic engine oils (Mobil1 and Amsoil) over regular dino oil. You're the first person that I know of that's dropped their engine oil pan to check this.

Great advice--I don't think I need to say anymore on the topic of changing the ATF (especially since each ATF drain and refill costs a meager $10).

PERRYinLA

Whether most of the ATF fluid is in the torque converter, or the torque converter and the valve bodies, cooler lines and other parts of the tranny, the point remains that it is not in the drain pan, so you'll never get most of the ATF out with a simple drain, which is the point hyperopt and I was trying to make.

Wynn Oil Company's own web page states "a typical transmission service replaces 40% or less...[ATF]". And I specifically mentioned cars, not trucks, but nice to know that your '97 bucks the norm.

mburnickas

SeattleGS400 quote:
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Originally posted by seattlegs400
Sure some change their oil religiously every 3K, some at 18K. I just happen to change my engine oil at 4-5K and my ATF around 10K. Maybe overkill on ATF, but it gives me a good piece of mind.
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Whatever makes you happy I guess ...nothing wrong with it
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Originally posted by seattlegs400
I wonder why Ford did this? Maybe they found the miracle ATF that lasts forever as you hinted or is their transmission significantly superior to all other car manufacturers for them to do this? I wonder about those car owners that drive their cars hard, modify their cars w/ supechargers, tow trailers, or those that just live in a hilly locale? Would you think that the higher ATF temps would cause the ATF (including additive and detergents) to breakdown over time? Wouldn't it need changing--no? Or is it just that Ford was cheap and decided to not put any drain plugs in that transmission or maybe they wanted to design their cars to last until 80K miles, upon which they want you as the consumer to buy a new transmission? Just because Ford sealed their transmission does in no way validate the fact that the ATF will last forever. Most fluids will oxidize over time (unless of course, you begin with an oxidized fluid, then it won't change), some are more resilient than others to oxidation, but given thermal stresses and also pressure cycles, fluids (and their additives) will break down and lose effectiveness over time--not to mention accumulate transmission particles over time from gear teeth engaging/disengaging during shifts.
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Ford had labels all over the tranny and I tried have a Ford dealer to drain it and a non-ford dealer and they both said nope, sorry. Higher temps will cause more stress on fluids. With oxidze over time. High heat is not good with ATF. The cooler the temp the longer life of fluid along with tranny.
The tranny in my Nitchback (LX 5.) was bullet proof and never had a problem. The new owner now has over 110K on it and he loves it. So, no Ford was not cheap with this tranny. My father is on the MA state police and they also have several LX 5.0 with same tranny. The like it.
I am not saying ATF will last forever but will better filtration it could last MUCH longer. Engine oil could outlast the engine with a bypass.
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Originally posted by seattlegs400

It was my understand that these fluids have additives to hold in suspension to ensure they flow to the filter and not fall the bottom of the pan or passages. If you use a nice fluid it should not have sludge problems. Doesn't sludge caused by junk oil and it then falls out or is burnt fluid? If you use a good fluid it will get filtered and/or not burnt. If you tranny gets that hot you have bigger things then fluid problems.

From an economical standpoint, isn't testing the ATF for fluid/chemical analysis cost a bit more than changing the fluid itself? Doesn't it run $12-29 per chemical analysist, depending on where you get it done? Maybe it's just me, but instead of testing the fluid to see if it needs to be changed, why not just change it for a lower cost ($10) and do something that you should have already been doing anyways?
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I am testing it at the drain. It cost about $10 and it would be nice to know what is going on with the tranny. If there are HIGH parts of Magnesium, aluminum, copper, etc something is up with it. Kind of like know before something breaks

nthach

i went over to Hanlees Hilltop Toyota in Richmond(the same guy owns Hanlees in Davis), got 4 quarts of T-IV, and i drained my old stuff, it was a reddish-brown, it smelled like old Dexron III fluid. Car shifts better on new T-IV. Should i flush it out at the next oil change, or let the dealer flush it out? I have almost 159,000 miles on it, my next oil change is at 160,000.

SeattleGS400

iTrader: (1)

NTHACH:

Considering your mielage, I'd drain and refill it mabye 2 more times yourself, then do a drain and refill along with the next 4 or 5 oil changes. It'll gently clear up your ATF of contaminants, and also gently clean up any sludge buildup. Doing a flush might be a bit too aggresive of a treatment for your particular vehicle, and you take the risk of clogging up your transmission internal parts (and A/T failure) from the shock of all new ATF at once.

FYI, once your ATF gets to a nice raspberry red color and smells sweet, you'll be in good shape, and then drain and refill once every 15K miles or so.

nthach

so how long should i keep this current cycle in? a few days?

SeattleGS400

iTrader: (1)

It depends on how many times have you drained and refilled your ATF. If you've just done it once, I'd do another drain and refill in the next week or so. However, if you've already done 2 drain and refills, you can change it again during the next oil change to save on time (and to also allow some of your new ATF to do some work on slowly cleaning your transmission). From there, I'd change out your ATF at every oil change until it's a nice strawberry/raspberry color with a sweet smell to it.

From your description of your fluid's condition, it will probably take about 4-5 total cycles to get it to an optimal state--but don't do too many sequential drains and refills at once as you might overload your A/T innards with many loose solid particles that can clog up your A/T and not allow the ATF detergents to bring it into liquid suspension fast enough. Other than the 2 sequential drain and refills initially (maybe up to 3 cycles), wait for a full engine oil change cycle to change the ATF again. Once the ATF is a good color from a few cycles, then you can stick with changing (refill and drain) your ATF once a year for good measure--draining out contaminants and to put in some fresh ATF.

I assume that you already know how to change the ATF by yourself, but for more info, go here:

http://lexusmodz.netfirms.com/

It's BananaGS's webpage, but has some of my past info on changing ATF for 98+ GS cars. His main page has lots of good info.

nthach

Of course i know how to change ATF, i've done it on a Cressida, and a few Mercedes. and that is good information you have there. Another question, should i replace the transmission filter?

mburnickas

Some tranny people say change it around 40,000 and never again. Then some dealers say every other change it. I am going for the everyother (on my ES) ATF change since the filter really does not catch that much. When I did it at 40,000 miles the filter looked new. Also the filters are metal and I do not feel as good as some felt filters but that is me.


But it is up to you.

SeattleGS400

iTrader: (1)

The transmission filter is just a metal mesh screen and not a felt filter, so I would not worry about it. I have previously talked with a couple of Lexus techs and some service managers, and they recommend the same thing--no change of the filter is required on the Lexus vehicles.

However, on other cars that do have felt filters, I would change those, but again, not on the Lexus cars with the mesh screen A/T filters (at least the newer generation models)