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Sc400 Transmission Flush


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Hey everyone. My 1994 SC400 has ~191K on it, and I was advised by a mechanic at the Lexus Dealership to flush the transmission.

First off, anyone know where I can find step-by-step instructions on performing the flush on my SC400? I found excellent instructions for a LS400, and If I understand correctly it uses the same 1UZ-FE engine and A341E transmission my car has. Has anyone attempted using those instructions on their SC400?

Also, my manual states that Toyota T-II ATF is needed. Has anyone had any problems using T-IV ATF instead? I believe T-II is discontinued.

I just got the car in May, following an accident with my beloved 1992 Acura Vigor. I have an Uncle who works for Lexus, so I was able to have it looked at by a friend of his. They think the transmission might be going (definitely not good), and said a Transmission Flush would improve its longetivity.

Thanks for your answers!

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I've read a lot of posts with differing opinions on doing a transmission flush and changing to type 4 toyota ATF. Even different lexus service managers disagree but this is what I was able to discern from all the different advice:

1) older SC400's with high miles should not get a transmission flush. Instead, gradually replace the type 2 with type 4 fluid along with each oil change (3,000mi or so) by dropping the transmission pan and draining 2-4 quarts at a time. Clean or replace your transmission filter when you do this. You should have mostly new type 4 by 4-6 changes.

2) low mile SC400's can probably be flushed and switched to type 4 ATF without problems.

3) Type 4 and type 2 ATF should be compatible but my service manager goes against the grain and likes to stick with the original type 2

So with your car (>100,000), perhaps a gradual change over might be a safer way to go.

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I found excellent instructions for a LS400, and If I understand correctly it uses the same 1UZ-FE engine and A341E transmission my car has.
1) older SC400's with high miles should not get a transmission flush. Instead, gradually replace the type 2 with type 4 fluid along with each oil change (3,000mi or so) by dropping the transmission pan and draining 2-4 quarts at a time. Clean or replace your transmission filter when you do this. You should have mostly new type 4 by 4-6 changes.

So with your car (>100,000), perhaps a gradual change over might be a safer way to go.

I tried a tranny flush and all was good for a while then the tranny died. do the 2qts change at a time and be on the safe side.

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I tried a tranny flush and all was good for a while then the tranny died. do the 2qts change at a time and be on the safe side.

How many miles did your Lexus have when you did the complete flush? Just curious. Thanks for your advice, everyone. I think I'm gonna play it safe and progressively flush it...

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I recently purchased a 95 sc400. One of the first services I had performed on the vehicle was a transmission flush.

Now it seems that 'may' have been an unwise idea. So my question is, can i reduce my risk of harming my transmission

by getting a second and maybe a third flush at 500 and 1000 miles respectively? Is the risk to my transmission the fact that there now may be some floating metal particles in my transmission -or- the fact that these particles were removed from(wherever they were) during the flush?

I don't really know much about cars ..... any advice members here can give me to reduce my risk would be much appreciated.

Btw - vehicle has 130k miles and unknown service record, tranny fluid looked Very bad coming out - black+burnt.

Thanks all.

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I've flushed the tranny fluid...Or changed it...However, I used a machine that sucks up the old fluid and replaces with new.. Very simple and most tranny shops and Jiffy Lubes use this machine...I replaced my fluid with Sythetic standard transmission fluid...T2 and T4 is overrated....

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I have a 94 sc300 137k miles, In the same situation, black fluid, probably never been changed for all I know.

What about doing the flush about 5-7 times with a cheaper transmisson fluid w/out starting the car inbetween flushes....does that make scense....And then finish with the appropriate transmission fluid.

I was considering doing this, just wondering what anyone else thinks?

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There is only two ways to flush your tranny fluid... This new machine that I talked about above which syphons then replaces the fluid from the top of the engine... An amazing machine and it takes about 20 minutes for it to work...

The conventional and most commonly used technique is to physically drop the pan from underneathe the car and then clean everything out...The pan should hold approx. two quarts of fluid.... You should repeat the process atleast two times...Maybe three times for a real proper flush..

Drive inbetween flushes too...

I change my fluid on my SC400 every 50,000 miles or so...I use only synthetic fluids.. Then again my ride is modified so the tranny works overtime which fry's the fluid faster.. I actually need to install a tranny cooler soon...Heat is what kills the transmission, so the cooler the tranny fluid stays the longer you can go without the flush, and also the tranny will last longer as well.. It's that simple..

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Jibbby- The service station put Wynn's TransFormer AT fluid in my RX300, after doing a transmission flush with another Wynn's product using their machine that gets all the metal filings out. The fluid "transforms Dexron III/Mercon ATF into a highly friction modified OEM replacement fluid".... so am I in trouble, or in big trouble now? OR (I hope) it's OK to leave the stuff in my transmission. The car runs fine, but they just did this 2 days ago.

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Alright, the reason a tranny flush becomes a bad idea is because if you don't change the fluid out every 30,000 miles or less, the fluid breaks down. This in turn creates tarnish. When you do a flush, you wash away the tarnish, and that leaves pits and spaces between the speed bands, gears,journals, and valves. That's what creates the problems. Tranny's start to slip, and won't shift etc. etc.

If you have gone more than 30,000 miles without a tranny flush, your better off not doing it at all after that point, and after the tranny has reached about 100,000 miles. Just leave it alone already. Your only taking unnecassary risks, and probably causing the problem. Unless your running a transmission cooler, which Jibby is correct, makes your fluid last longer as heat is what breaks down the fluid in the first place. And Jibby, the machine your talking about is the Ranger, RT-15X trannsmission fluid exchanger. ( My dad has one at his shop.) And your right, it's a nice toy to have around. ;)

So, it's at this point that just draining a little at atime and replacing it slowly comes in as a good alternative to a full flush.

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I agree with every thing Smooth says...However, I still think it is a good idea to replace very old transmission fluid...If the color of the fluid is not red anymore I would say it is time for a change...If it smells burnt change it...

I am not a transmission expert but I do have experience and that is what I have always done for more then 20 years..... I have flushed the tranny fluid half a dozen times on the SC4's as I use to buy and sell them...Never had one slip after a flush, infact they always seemed to run a little smoother... Just my take...

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I agree with every thing Smooth says...However, I still think it is a good idea to replace very old transmission fluid...If the color of the fluid is not red anymore I would say it is time for a change...If it smells burnt change it...

I am not a transmission expert but I do have experience and that is what I have always done for more then 20 years..... I have flushed the tranny fluid half a dozen times on the SC4's as I use to buy and sell them...Never had one slip after a flush, infact they always seemed to run a little smoother... Just my take...

...However, I still think it is a good idea to replace very old transmission fluid.

That's why I said in my previous post :

So, it's at this point that just draining a little at atime and replacing it slowly comes in as a good alternative to a full flush.
If the color of the fluid is not red anymore I would say it is time for a change...If it smells burnt change it...

The color of the tranny fluid will not be red after about 3,000 miles. The better way is to put a drop on a white paper towel. The center of the drop will be a maroon/brown color and an outer ring should develope after about 15 seconds or so. How much of the outer ring that is red will be a good tell. If there is no ring of red, then you should replace the fluid.

I think you and I are on the same page, but we need to clear some verbage up. If you drain and drop the tranny pan, replace the filter and lock it back up, and refill, you still have the old fluid in the system that you can't get to. So the old will mix with the new. this is not bad advice for those who have gone a long time without a tranny service. But I would stop at this point. Wait 6 months to a year,and just drop the fluid from the pan and replace it. I don't know that doing it 2 or 3 times is good for old trannys. This we'll call changing the tranny fluid.

To flush the tranny is different in that it uses a mechanical fluid exchanger and the cars own pump and hooks into the cooler lines off the radiator. As the car runs and it pumps the fluid out, the machine replaces it with the exact same amount of fluid. Then the car is run through all the gears. After that we drop the pan replace the filter, lock it back up and run it thru the fluid exchanger again. ( The system has a safety bypass that stops the machine from over filling the tranny, and not under filling as well.) This flush is only recommended if you have the tranny flushed on a regular basis. ( every 30,000 miles) This we'll call a tranny flush.

So, you can change the tranny fluid regularly to keep the transmission fluid fresher on any transmission that has not had regular flushes, But you have to have it flushed regularly if you want to go that route.

So, Jibby, I think we were saying the same things, we just needed to clear up the details. B)

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If you don't know the history of the 100K plus car, the most important tests you can do at home are color and smell. Red/Reddish color means that the previous owner(s) probably had the transmission serviced; drain fliud, take off pan & filter and look closely at filter - again, you can probably tell if it has been replaced. Put new filter in, clean out pan and seal unit up, replacing the fluid with ATF III or IV - it will take a little more than 2 quarts, so put in two and drive a bit till warm, and add a little more as needed. Then, check level, color and smell when you get gas, draining pan every 2000-3000 miles and adding fluid as necessary - do this 3-4 times and you will be fine.

Darker reddish-brown fluid requires a more aggressive version of the above, but as long as the fluid isn't burnt smelling you should be ok after a few more cycles of the above. Really dark brown (no red) and/or burnt smelling fluid is a good reason not to buy the car, but if you do or already own the car, it it worth trying a super-aggressive version of the above, with the second and third treatments at 100 and 300 miles and another new filter at 300.

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If you don't know the history of the 100K plus car, the most important tests you can do at home are color and smell. Red/Reddish color means that the previous owner(s) probably had the transmission serviced; drain fliud, take off pan & filter and look closely at filter - again, you can probably tell if it has been replaced. Put new filter in, clean out pan and seal unit up, replacing the fluid with ATF III or IV - it will take a little more than 2 quarts, so put in two and drive a bit till warm, and add a little more as needed. Then, check level, color and smell when you get gas, draining pan every 2000-3000 miles and adding fluid as necessary - do this 3-4 times and you will be fine.

Darker reddish-brown fluid requires a more aggressive version of the above, but as long as the fluid isn't burnt smelling you should be ok after a few more cycles of the above. Really dark brown (no red) and/or burnt smelling fluid is a good reason not to buy the car, but if you do or already own the car, it it worth trying a super-aggressive version of the above, with the second and third treatments at 100 and 300 miles and another new filter at 300.

If you don't know the history of the 100K plus car, the most important tests you can do at home are color and smell. Red/Reddish color means that the previous owner(s) probably had the transmission serviced;

But what if the car went 100k miles with no tranny services, then the owner replaced the fluid and filter say within the last 3,000 miles? Then you still wouldn't know anything or assume incorrectly.

Red/Reddish color means that the previous owner(s) probably had the transmission serviced;

What, less than 3,000 miles ago? Because after that, it's all the same.

Darker reddish-brown fluid requires a more aggressive version of the above

I would challenge anyone to tell the difference between tranny fluid that is 5k miles and 60k miles used. I've changed so many tranny's out and flushed and you name it, and there is no way you can tell the difference by looking at the fluid.

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Read my post more carefully: My service recommendation does not depend on being able to tell the "difference" between 3k, 5K and 30K or 60K fluid. My recommendation is intended to help the new owner of a 100k car who knows nothing about the previous trans service. If the trans fluid in such a car is mostly/predominantly red the conclusion can be safely drawn that there has at least been SOME trans service - this ia a far different situation than such a car with dark brown/no red fluid (the towel test is a good one, BTW) which may have had NO service. All I have posted is a service schedule for the new owner who only has the color and smell of the trans fluid to go on. Peace.

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Read my post more carefully: My service recommendation does not depend on being able to tell the "difference" between 3k, 5K and 30K or 60K fluid. My recommendation is intended to help the new owner of a 100k car who knows nothing about the previous trans service. If the trans fluid in such a car is mostly/predominantly red the conclusion can be safely drawn that there has at least been SOME trans service - this ia a far different situation than such a car with dark brown/no red fluid (the towel test is a good one, BTW) which may have had NO service. All I have posted is a service schedule for the new owner who only has the color and smell of the trans fluid to go on. Peace.

It's all good bro.

But I have to strongly disagree with your statement about aggresively cleaning really dark brown to burnt smelling tranny fluid. Your going to make a bad situation worse. At the point of burnt tranny fluid, or no service tranny's, there will be alot of tarnish on everything inside that tranny. You start cleaning that tranny and your going to create gaps and spaces everywhere, which will only accelerate the demise of the transmission. At this point, just drop some fluid and replace it slowly over time.

I know there are people who will read this and disagree with me. But if you don't do regular flushes, don't have your tranny flushed. If you have purchased a high mileage vehicle and can't confirm regular service flushes, assume they weren't done, and just replace the fluid in the pan over time on a regular basis only. If you have a new car, have the tranny flushed every 30k miles, 50k if you have a tranny cooler and don't run it hard.

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We can agree to disagree. BTW, I recommend the same theory & approach when a new owner of a 100K SC car looks at/smells the PS fluid and the hydraulic fan fluid; again, if the fluid is reddish at all, it's had to have had some attention. The easiest way to adrress it is with a turkey baster or an old anti-freeze tester with a rubber squeeze bulb. Suck out as much of the old brownish fluid as you can from the reservior and then replace it with ATF III or IV, being very careful not to overfill; assuming that the car is driven, repeat this drill every week until the fluid is a more healthy red color. Sure, you can pay someone to "flush" these systems (like the trans), but it's really a rip to do it that way. My approach is very easily done and accomplishes the same/similar result with just basic tools and skills.

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  • 1 year later...

I would like to thank the both of you for your advice. I wished i had seen this post when i had the transmission in my 92' 400 w/190k flushed at my local toyota dealership. If it wasn't bad enough that they overfilled it by over a quart(coming out filler when warmed up)they also did a S**t job by what i could tell when i dropped the pan and cleaned it and replaced the filter. My car had only been driven 1k miles since flush and my fluid was not reddish at all. Very gritty and my magnets were very gritty as well. I went with the flush because i was told the filter was not replaceable(per lithia toyota in Medford, OR) and i was getting a little slip and a vibration at around 30mph in town. Also knocked you a bit when selecting gears from park. They said "oh yeah, we will flush it and you'll be back in business." Yea F'ing right! The overfill was making driving nearly disgusting. I was slipping and hard shifting and taking a long time to go between gears. Had to go back 3 more times and shove the dipstick in the service managers face to get him to admit they hadn't checked it like i was told twice and they put it on the rack and still left too much fluid in.

Long story short, i agree with the dropping of the pan and cleaning it and changing the filter and using new fluid and repeating the drain every month or so until the fluid is newer than it was. I used dexron/mercon III and i think it works better than toyota type IV(toyota dealership refilled with this) but like i said i also changed the filter so that might be my bias.

Also a side note to those who aren't mechanics are even mechanically inclined, my hard shifting when in park and selecting drive or reverse was not corrected by this. Albeit, my shifts are smoother and driving is more enjoyable. I later pulled my transmission mount(lexus calls this rear motor mount?) and checked it and it was still intact. My vibration must be due to motor mounts which i will pull this weekend and check before i order as they will cost nearly $200 to replace myself. Hope this helps someone and please read this post if you have a shudder or vibration, could save lots of time/money. http://us.lexusownersclub.com/forums/index...showtopic=30681

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Hi Ben, I was reading one or your posts and was wondering if you could help me out...

My 2004 ES330 does the same thing that you mentioned in a post. Shifting from park to drive, or from park to reverse, it shifts HARD. and also depends how bad by the rpm..

My question is what did you do to fix it ? I was told by someone on the forum to replace the tranny fluid, which I will. But you mention it didn't fix it ?

I have 80,000 miles and just bought it, and the fluid is red, but "kinda" dirty... not black smudge dirty, but not impressive either.. .

Any help, or light you could shed on the subject would be greatly apreciated.. thanks !!

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Hi there.

I've got 190k on my tranny. It runs ok. I owned a carg since 130k miles. Replaced tranny filter once. Color of transmision fluid is fine (brown-reddish). However tranny is slightly overfilled. I checked dipstic and see that level is above "hot" range even though i was checking while tranny was cold.

Should i do anything about it at all? Car shifts and drives ok.

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Hi there.

I've got 190k on my tranny. It runs ok. I owned a carg since 130k miles. Replaced tranny filter once. Color of transmision fluid is fine (brown-reddish). However tranny is slightly overfilled. I checked dipstic and see that level is above "hot" range even though i was checking while tranny was cold.

Should i do anything about it at all? Car shifts and drives ok.

My car was acting up due to overfill. On the other hand my car was EXTREMELY overfilled all the way up filler tube. I've been told it won't hurt it but if you go to a quick lube they will stick a tube in your filler and suck some out and typically won't charge. At least i never get charged. Maybe that helps?

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  • 5 months later...

Is there really a trans filter element to replace, or is it just a screen filter that has to be cleaned? I can't seem to find a part number for

trans filter, or trans pan gasket? I flushed the fluid in my '93 SC400 at 100k, but would like to do it again at 120K. I have a case of T-IV ready for the flush...

Is there a need to change the filter, if there is one, and how often for filter changes, or screen cleaning? I had the flush, and supposedly

a filter change at 100k miles. The mechanic said there was no gasket, so he used a thin bead of silicone. No leaks or problems for the last 20k miles.

Can't get in touch with that independent mechanic, as the shop has since closed down...

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