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Correcting Wrong Transmission Fluid


allegoric
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I have a 94 LS400 with 217K and recently learned that my mechanic used Dex III when doing a transmission pan only and filter change. Since I have no idea what this percentage was mixed with originally should I leave it alone or is it important to get the Dex slowly with multiple changes to Toyota IV? It shifts a little hard when cold and a little slip from first to second, there is a bit of a smell, but I don't want to make things worse than they are. I have read threads relating to this fluid difference and it doesn't appear to be a clear cut judgment of what to do in this case.

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if it were me, I would do a total system flush ... they hook up their equipment to your transmission cooling lines and pump out the entire contents of your system and put in the new fluid ....

My Independent Mechanic is a Toyota guru and he strongly advised that we go into a synthetic Transmission fluid ..... like I said ... he IS a real guru ( 30 plus years doing this) ... so I said yes. GLAD I did. I noticed much better performance overall in my transmission ..... we did this service at about 110,000 miles which is also when I had bought this car ( 95 LS 400) .... At stone cold it shifts smooth, but before we serviced my trans. it would kind of hang in 2nd gear when it was still cold .... but not now. It shifts smoothly now in all ranges and speeds. This cost me about $200 and it also included a new filter .... I think this price is kind of high, but I think he had to really flush it good, cuz it was pretty dirty when I got the car; so perhaps he allowed more fluid to run through the system to achieve the transition from standard toyota fluid and into the new synthetic fluid .... it was over-due in my case ... for sure ....

I think this would totally solve your problem .... and it sure is less expensive than the potential [greater] problems in the future if you do not do this soon ....

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I appreciate your replies, I am going to switch to the Toyota IV regular fluid I think, gradually doing it in three drains, I think the synthetic is dangerous after the car has run 217K most probably with regular Toyota fluid or Dex I think would cover the 95% of possibilities. I can't afford the flush, nor do I have anyone around here that I trust, this being Orange County, people don't rank in the altruistic around here, it's all about how much money they can get from you. Thanks again.

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i would go to a corporate owned establishment such as pep boys, they are not in the business to get over on people, any complaints that are not properly dealt with in store by the manager is taken to district managers and so forth, i used to be a service writer for pep boys.....trust me when i tell u that their work is backed by their name..if u do make sure u supply the trans fluid as they dont carry the toyots type 4 u need...i would flush it out btw

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You can flush it youself using the transmission cooler line that connects to the radiator. I did it and it was messy, but EASY. The gurus on here will be able to tell you where to find it on the site, but I think it is hosted on another guys page though.

Good luck!

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You can flush it youself using the transmission cooler line that connects to the radiator. I did it and it was messy, but EASY. The gurus on here will be able to tell you where to find it on the site, but I think it is hosted on another guys page though.

Good luck!

Anybody know where that video is on how to flush a LS400 transmission????

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Sounds plausible but can anyone explain to me why this method of flushing would be better than just removing the drain

plug and taking out 2 liters at a time? Seems like both would mix the old with the new to some extent which would require

a little more new fluid to do a complete flush. I guess removing the radiator transmission line would be a bit faster because all

you would have to do is stop the engine to stop the flow. The drain plug method puts more wear-n-tear on the plug and would take more time.

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with multiple drain and fills the fluid mixes between each drain, so with successive drains you're only removing a declining percentage of the old fluid.

with the LexLS flush you're taking old fluid out of the bottom, and adding new to the top (a few quarts at a time), and there is not nearly as much mixing going on.

Think of a gatorade cooler filled with old oil. Drain 2 quarts out of it, put 2 quarts in on top. Would you want to shake it before you repeat to get as much old fluid out as possible (no), or just let the new fluid sit on top until all of the old is gone (yes)?

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If you haven't done a flush for some time or ever, I would recommend multiple drains. A one time flush is more convenient but also has the risk of cleaning off the varnish buildup all at once which can clog some of the passageways. Multiple drains allow for the cleaning to ocurr gradually, minimizing this risk. Dropping the pan to clean out the mags & filter screen should be also done for a unit that hasn't seen any service in a long time or ever. Once there's new fluid in there, followup single flushes, using the LexLS method, would be the way to go.

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with multiple drain and fills the fluid mixes between each drain, so with successive drains you're only removing a declining percentage of the old fluid.

with the LexLS flush you're taking old fluid out of the bottom, and adding new to the top (a few quarts at a time), and there is not nearly as much mixing going on.

Think of a gatorade cooler filled with old oil. Drain 2 quarts out of it, put 2 quarts in on top. Would you want to shake it before you repeat to get as much old fluid out as possible (no), or just let the new fluid sit on top until all of the old is gone (yes)?

Ok, I think that makes some sense. Certainly, the first 2 liters are 100% old fluid with either drain method. However, the second drain

would be a mix with the drain plug method but pretty much pure old with the radiator line drain method. Thereafter, there will be some mixing

with both methods. But getting about half of the old stuff out right off the bat is a huge advantage.

Now, does the new fluid really float(set) on top of the old? (BTW, good post chilkoot. Gave me lots to think about).

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here is an idea .... look up BOBBY LIKIS ... he has CAR CLINIC RADIO.COM .... Bobby is an ultra automotive guru to the 10th power .... his opinion on the subject of doing a transmission flush would be valid, as he has been in the automotive repair business for so long. His business is huge.

I know that I have E mailed Bobby with questions several times in the past, and he always answered me every time .... he is very intelligent and is dedicated to always doing things the correct way .... I feel I have learned much from him ...

food for thought .... hope you check him out ...

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