Automatic Transmission Fluid Change

[LS 0181158]

My 1998 LS 400 has between 120-121K miles on it now, and I had planned to address a transmission fluid change--which I understand is to be done every 30,000 miles. When I brought the car to the local Penzoil shop for an oil change 1K miles ago, the tech advised me that the automatic transmission fluid was quite dirty and recommended FLUSHING and replacing the transmission fluid.

I've only had the car since 116K, so I am not intimately familiar with either its past maintenance history or specific procedures necessary for service. But I want to take as perfect care of the car as possible, as it's in near-flawless condition cosmetically AND mechanically.

My questions are as follows:

1. Allow them to FLUSH the fluid, or DRAIN and replace only? I have heard that flushing can generally be damaging to the transmission, although draining will not allow as much fluid to be replaced unless it's done repeatedly in short order.

2. Should I specify only a certain type of fluid be used as replacement? I know the Owner's Manual will advise the generic TYPE of fluid, but do you feel it's actually worth purchasing a specific BRAND from the Lexus dealer or auto parts store? For instance, I know that the coolant should be the red Toyota kind, and not the generic green variety--so I was wondering if a similar rule applies for the automatic transmission fluid?

3. My 1998 UCF20 has the 5-speed automatic, vs. the 1995-1997 models with only the 4-speed. Should any special attention be paid as a result of this fact?

4. Finally, do you feel it's a bad idea to ask a place like the Penzoil shop to perform this service on my car? I'm not someone who would typically jack up the car and do this myself, but I also see no reason to pay the Lexus dealership big $$$ to do a relatively simple service such as this. Any thoughts?

Thanks very much for any wisdom you can offer!

[eatingupblacktop]

Power flushes create too much pressure and can cause problems.

Here's a link to the safe way to flush your tranny just so you will know what's involved:

http://www.lexls.com/tutorials/transmission/transflush.html

You're right about doing changes often. You will eventually have mostly fresh fluid. If the fluid is dirty as the shop told you, you should clean or replace the filter as well. If you're not a diy, then I would change the tranny fluid at a Toyota dealer and save some bucks. The fluid you want to use is Toyota Type IV ATF.

[LS 0181158]

OK, thanks very much! I will try to schedule a time at the local Toyota dealership, and make sure they use the fluid you specified--and DRAIN and refill the fluid rather than flush it. Penzoil wanted $110 for the service--I imagine the Toyota dealer would be a little more? I checked out the tutorial, and it doesn't look that hard. I just don't have the place or adequate tools to do this, and I'd feel more comfortable having a "professional" do this, although I'm sure I agree with most that no one can really be trusted regardless of where you go.

Would you say I'd be good for another 30,000 miles after getting this done?

The manual also indicates changing the brake fluid, coolant and spark plugs at 120K, asl well as having lots and lots of other stuff inspected. Any recommendations with regard to this? I'm more likely to get this maintenance done piecemeal rather than paying for it all at once--but regardless, I'll try to address the other fluids and spark plugs ASAP.

[wwest]

Power flushes create too much pressure and can cause problems.

Here's a link to the safe way to flush your tranny just so you will know what's involved:

http://www.lexls.com/tutorials/transmission/transflush.html

You're right about doing changes often. You will eventually have mostly fresh fluid. If the fluid is dirty as the shop told you, you should clean or replace the filter as well. If you're not a diy, then I would change the tranny fluid at a Toyota dealer and save some bucks. The fluid you want to use is Toyota Type IV ATF.

If you drop and clean the debris out of the sump pan first then a power flush afterwards will do not harm and is probably a better choice than "piece-mealing" the ATF change out/over.

[eatingupblacktop]

Power flushes create too much pressure and can cause problems.

Here's a link to the safe way to flush your tranny just so you will know what's involved:

http://www.lexls.com/tutorials/transmission/transflush.html

You're right about doing changes often. You will eventually have mostly fresh fluid. If the fluid is dirty as the shop told you, you should clean or replace the filter as well. If you're not a diy, then I would change the tranny fluid at a Toyota dealer and save some bucks. The fluid you want to use is Toyota Type IV ATF.

If you drop and clean the debris out of the sump pan first then a power flush afterwards will do not harm and is probably a better choice than "piece-mealing" the ATF change out/over.

In principle sounds ok, but depending on the service history, there could be caked on crap elsewhere in the system that becomes dislodged with a power flush and winds up clogging some of the smaller passageways. Better safe than sorry. I do agree that doing multiple changes to achieve complete replentishment is not most expedient. For me the tutorial has it right on the money.

[Lexusfreak]

I suggest Amsoil synthetic ATF (meets all of Toyota Type IV specs). Awesome stuff & improves shift quality bigtime. More info here...

http://www.amsoil.com/StoreFront/atf.aspx

[wwest]

Power flushes create too much pressure and can cause problems.

Here's a link to the safe way to flush your tranny just so you will know what's involved:

http://www.lexls.com/tutorials/transmission/transflush.html

You're right about doing changes often. You will eventually have mostly fresh fluid. If the fluid is dirty as the shop told you, you should clean or replace the filter as well. If you're not a diy, then I would change the tranny fluid at a Toyota dealer and save some bucks. The fluid you want to use is Toyota Type IV ATF.

If you drop and clean the debris out of the sump pan first then a power flush afterwards will do not harm and is probably a better choice than "piece-mealing" the ATF change out/over.

In principle sounds ok, but depending on the service history, there could be caked on crap elsewhere in the system that becomes dislodged with a power flush and winds up clogging some of the smaller passageways. Better safe than sorry. I do agree that doing multiple changes to achieve complete replentishment is not most expedient. For me the tutorial has it right on the money.

If you consider that ATF operating pressures go up to something in the range of 3000 PSI I can't imagine a "power flush" having enough pressure to dislodge something that normal operation hasn't.

Our '95 LS400 is going in next Tuesday for the pan to be dropped and cleaned and then a power flush, first one in 210,000 miles insofar as I am aware. Brake bleed and power stearing fluid also.

[eatingupblacktop]

If you drop and clean the debris out of the sump pan first then a power flush afterwards will do not harm and is probably a better choice than "piece-mealing" the ATF change out/over.

If you consider that ATF operating pressures go up to something in the range of 3000 PSI I can't imagine a "power flush" having enough pressure to dislodge something that normal operation hasn't.

I disagree with your premise that a power flush "will do no harm" even after "you drop and clean the debris out of the sump pan first". First of all, flush machines force powerfull cleaning solvents at high pressure in a reversed flow back through the transmission to clean out accumulated junk that has formed through the breakdown of the fluid. This high pressured reverse flow of aggressive solvents does break off chunks of sludge, but it forces them backwards through one-way valves and galleries often wedging and trapping them in there. The result is that normal flow of the fluid is reduced or even cut off resulting in abnormal or lack of shifting in the tranny. The absence of lubricaton eventually ends in failure of the tranny. The inevitable repairs are expensive. Toyota along with most manufacturers does not recommend power flushes. Even manufacturers of power flush machines advise in their manuals not to use them on high mileage machines. I reiterate, the only safe flush is as described in the link previously posted.

[mburnickas]

For me, flushes are fine (if you want to do it). I think they are overstated just like the engine oil gelling issue. You do NOT have to take the filter off every ATF change (unless you are doing extended drains; 50 to 90K miles). You can drain ATF and just refill with ATF. You are wasting money but changing filter every time.

If you have something bad happen with a flush, it was full of crap and would have happened down the road.

If you use a good flush and change as UOA show, you are fine. I change my fluid (ATF) at about 35 to 45K miles and it comes out mint (using Amsoil ATF). Used it for about last 12 years and works fint.

Lastly, I trust Toyota on fluid like snake-oil salesman. They know jack s%^t.

[dcfish]

For me, flushes are fine (if you want to do it). I think they are overstated just like the engine oil gelling issue. You do NOT have to take the filter off every ATF change (unless you are doing extended drains; 50 to 90K miles). You can drain ATF and just refill with ATF. You are wasting money but changing filter every time.

If you have something bad happen with a flush, it was full of crap and would have happened down the road.

If you use a good flush and change as UOA show, you are fine. I change my fluid (ATF) at about 35 to 45K miles and it comes out mint (using Amsoil ATF). Used it for about last 12 years and works fint.

Lastly, I trust Toyota on fluid like snake-oil salesman. They know jack s%^t.

Here we go again , A typical oil/atf thread going down the drain, Close her up Mods. :whistles:

[mburnickas]

Here we go again , A typical oil/atf thread going down the drain, Close her up Mods. :whistles:

No, posting a fact based on my past usage, testing etc...unlike others.

It is funny, is this not the foundation for a forum.

[dcfish]

Here we go again , A typical oil/atf thread going down the drain, Close her up Mods. :whistles:

No, posting a fact based on my past usage, testing etc...unlike others.

It is funny, is this not the foundation for a forum.

That's all well and good, I am saying that these forums have a slew of this type of discussion and all too often another thread is started rehashing the endless debate. It's just beat, Like the proverbial dead horse.

[mburnickas]

That's all well and good, I am saying that these forums have a slew of this type of discussion and all too often another thread is started rehashing the endless debate. It's just beat, Like the proverbial dead horse.

Problem is people learn, I hope, and grow. Older thread are nice for ref but things do change.

I say, for me, if people do not know about oils, UOA, CA, ZDDP, etc then do not beat the "proverbial dead horse". Let the people who do know post.

It is the people that blindly give postings as fact that are not.

[Kennyr]

I'm surprised the toyota ATF only loyalists havent jumped in yet. I use BG universal synthetic (it's probably made by Amxoil for all I know) but my trans (160k on it) shifts way smoother than with Toyota brand. I used to get a rough shift that *BLEEP*ed me off but for the last 50k (2 flushes with BG) my shifts are so smooth. I do it myself without a machine as described in the tutorial. I would not be afraid to use the flush machine if I had one though. $120 or less is a good deal for a pr flush. Make sure they use Toy or Amsoil though. Also on another note, if you have a leak in your pr. steering system pour a 1/3 of a small cap full of brake fluid into the resevoir. This swells the seals in the rack or wherever its leaking. Works real nice sometimes. It fixed my steering rack pinion seal leak. I bought an aftermarket rack online but never installed it since my leak has stopped. I'm a mechanic and I have seen this work many times.

[wwest]

For me, flushes are fine (if you want to do it). I think they are overstated just like the engine oil gelling issue. You do NOT have to take the filter off every ATF change (unless you are doing extended drains; 50 to 90K miles). You can drain ATF and just refill with ATF. You are wasting money but changing filter every time.

If you have something bad happen with a flush, it was full of crap and would have happened down the road.

If you use a good flush and change as UOA show, you are fine. I change my fluid (ATF) at about 35 to 45K miles and it comes out mint (using Amsoil ATF). Used it for about last 12 years and works fint.

Lastly, I trust Toyota on fluid like snake-oil salesman. They know jack s%^t.

Speaking of postings as fact.....

The basis of Amsoil's knowledge base of ATF is.....

[mburnickas]

Speaking of postings as fact.....

The basis of Amsoil's knowledge base of ATF is.....

For Amsoil it is over 30+ years of ATF/fluids and well, call their Tech dept. Talk to Ed, he knows his stuff. I do not sell the stuff so I do not know all. Just know what I have used and the data for me.

For me, I have done to many UOA on the stuff (engine and ATF) when I had my old 5.0, my diesel truck/tractor and now my Lexus. The stuff performed well and I drained before needed. The most I had on it was over 70K.

I do not post them anymore since people do not understand it, nor care or think there old-school method works.

To close, you really do not need to get a new filter for my Es. Lexus makes stainless steel filter and you could clean and re-install. PLus draining at like 15 to 20K miles is a joke.

So far, Amsoil fluids are the most up-to-date products going. And that is from someone who dislikes certain aspects of there business. They wrote the book on it.

[PilotguyPA28]

I was told if it hasn't been done regularly then leave it alone. To flush and replace can cause problems since the old fluid is probably helping hold old parts (with greater tolerances) together in tighter tolerance.

[rickatups]

I have 4 cars that I have done a complete system flush on ( 2 of them LS 400 ) ..... all of them were ready for a trans. service anyway ..... we replaced the standard fluid with synthetic, and all of the cars seem to be performing very well since. I have had no problems ...... I have noticed obvious improved performance from the transmission on each car we have done this to.

I have a really good independent mechanic that did all these cars for me ..... he is one of those rare finds in the automotive business .... extremely knowledgeable and experienced and has all the best tools / equipment in his shop. He is honest as well. He does not cut corners. The down side is how much he charges ..... but he always gets it right every time.

What ever method he uses when flushing a transmission has worked for me ...... I know he is doing the total flush and fluid exchange of the entire system, but what pressure level his machine is set at, I am not sure of ....

anyways ... the point is ...... we have had no problems since .... soooooooooooo .... I would be inclined to continue this method with future system flushes ...

not sure if this helps ... but hope so ....

[brooklyn sc4]

<_< well for the record let me say that im the new guy on the block........ive got a 92 sc400 267,501 miles i did a high pressure tranny flush about 450 miles ago the shifts are about 30% better overall and the power DELIVERY is about 25% better would i do it again....... well after what i read from both sides of the fence i would ask a few more questions of the person doing the flush but yes i would :D

[Jim_Chow]

Flushing can cause damage on a transmission. Since your fluid is old, the safest thing to do is a simple drain & fill (about 3-4 qts, maybe 1/4-1/3 of the total capacity). Do this gradually (say every oil change) rather than replacing 100% of the fluid. Normally, you should replace the fluid about every 30K mi, a little longer if synthetic. You should have a "transfusion" done, not a power flush. The transfusion merely plugs a machine into the ATF lines. One resevoir in the machine contains new ATF, another resevoir catches the old ATF. You drain & fill the ATF pan, then put the new ATF in the machine's tank, turn on the engine until theh new fluid has been sucked into the tranny. Meanwhile, the old fluid returns to the tank rather than the ATF pan. Stop engine and reconnect lines. There is no pressure on the tranny using this method.

[paulo57509]

FWIW, flushing is the only transmission maintenance service that my local Lexus dealer recommends. They don't even stock the strainer.

[jpourcy]

Hi Guys,

I can't find anywhere in the Lexus service manual about replacing the ATF strainer or even taking the pan down and cleaning it. Is this even necessary?

Would just a change of fluid do the trick or should the pan be dropped, clean or replace the strainer, and clean the pan also?

I have been told the strainer in the LS 400 transmission is not even a filter but rather just a strainer. Does it need to be cleaned? Why isn't this in the service manual?

I bought my 91 with 117k and now it has 168k and I have never done anything to the transmission, but I would like to do preventative maintenance. What is the best route to take since the service manual doesn't say anything about it? (I find that kind of strange.) The only thing I can find is about draining the pan and adding a couple of quarts of fluid.

What is your method that you prefer and what kind of results did you get?

Thanks.

Jerry

[Vegituh]

does super tech multi-vehicle ATF work on a 1992 lexus ls400

[billydpowell]

The fluid you want to use is Toyota Type IV ATF.

[vonda007]

I agree with you!