Dirty Transmission Fluid
#1
Driver School Candidate
Thread Starter
Dirty Transmission Fluid
2001 LS 430, 166k , My tranny fluid looks dark and I believe it smells burnt...i think. Car shifts fine, no shifting problems or delays. I want to change the fluid but I dont necessarily want to drop the pan. Can I just drain using the drain bolt and replenish what i take out? Also, when i fill through the dipstick, does that fluid go right back into the pan or wherever i just drained it from? Should i do a drain and fill 3 or 4 times to get most of the bad fluid out? From all the things I've heard I am scared to do a flush.Are there temperature issues?
#2
Lexus Fanatic
Your car should have a dipstick so you can easily get the level right....BUT, I have heard one should not touch the fluid if burnt (seems to be the consensus?)....I don't mean if it's low don't bring it up, but again I've heard not to change if burnt....someone else can correct me if I'm wrong....
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Carheart (11-17-17)
#3
Lexus Test Driver
iTrader: (2)
Dump the pan and filter and change the fluid. Because the torque converter holds 2/3's of the fluid, you can get more out by starting it for like 5seconds once the initial fluid drop is done.
Once new filter and pan are installed; When filling, ONLY put back what came out in the initial dump or you will overfill and make a huge mess.
So, if 3qts came out from pulling the plug, fill with 3qts and start it. It still has like 3 to 4qts in it, so leave it idle and keep filling. Once close to the total volume you removed, put it in both drive and reverse for a minute.
If the drive wheels are off the ground and IT IS SAFE TO DO SO, run it through the gears. You don't need to go 90 just get through a couple gears and then secure it in park and check the level.
There are 100 reasons fluid burns, but getting it out is the best course. If you plan to do several dumps to get it all out, just make sure its full and do a 10min drive and repeat process minus pan drop.
i.e. pull plug, dump contents, start it for 5 to 7 secs and let that run out. Install plug. Fill 3qts, start it, fill remainder. Test drive.
Lets kill the old wives tales from the 60's when fluid would varnish and fluid change killed the trans. Fluid and technology is much better today. But burned fluid lost valuable properties and needs replaced esp if trans is working fine.
? Question - do you tow with it?
Once new filter and pan are installed; When filling, ONLY put back what came out in the initial dump or you will overfill and make a huge mess.
So, if 3qts came out from pulling the plug, fill with 3qts and start it. It still has like 3 to 4qts in it, so leave it idle and keep filling. Once close to the total volume you removed, put it in both drive and reverse for a minute.
If the drive wheels are off the ground and IT IS SAFE TO DO SO, run it through the gears. You don't need to go 90 just get through a couple gears and then secure it in park and check the level.
There are 100 reasons fluid burns, but getting it out is the best course. If you plan to do several dumps to get it all out, just make sure its full and do a 10min drive and repeat process minus pan drop.
i.e. pull plug, dump contents, start it for 5 to 7 secs and let that run out. Install plug. Fill 3qts, start it, fill remainder. Test drive.
Lets kill the old wives tales from the 60's when fluid would varnish and fluid change killed the trans. Fluid and technology is much better today. But burned fluid lost valuable properties and needs replaced esp if trans is working fine.
? Question - do you tow with it?
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Carheart (11-17-17)
#4
Absolutely I'd change that fluid out. But, I'd exchange all of the fluid by pulling the trans cooler line and letting the trans pump it out (couple quarts at a time). There's a How-To somewhere on this forum.
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Carheart (11-17-17)
#5
Super Moderator
iTrader: (6)
+1 to the above posts of getting some fresh fluid in. Leaving the burnt additive package fluid in further depletion will translate into a transmission rebuild or similar search for a wrecking yard replacement. My Toyota guy has told me he sees transmissions go south in the 150-180K range without any fluid maintenance. Do the fluid exchange and evaluate how the transmission is following.
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Carheart (11-17-17)
#6
I'd be extremely careful when it comes to your next move. You already mentioned that the car shifts smoothly and you mentioined you think the fluid looks dark and possibly smells burnt. Before doing another thing.. you have one major thing in your favor. Your car shifts as it should. Go to a shop you trust (not necessarily Lexus) and ask them to inspect your fluid. If you had mentioned your car is not shifting correctly.. that is another story and you would have no choice to to change the fluid. Here you have a high mileage car that by changing the fluid and by changing all of the fluid, you might very well end up with a car that won't shift or even move! The varnish that has built up over time might be the only thing holding your transmission's clutches from slipping. Changing transmission fluid (unless you are the original owner) might be a throw of the dice... be careful my friend. Do yourself a favor and reread the post from Johnhav430. It might be very relevant. You want to do the right thing, but it might not necessarily go that way. If it were me? I'd leave well enough alone until I had a problem which you might not ever have. Good luck and let us know how it works out.
Last edited by Bocatrip; 11-17-17 at 03:33 PM.
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Carheart (11-17-17)
#7
Moderator
There is no way you are going to cause any negative issue with your AT by doing a simple 3 quart ATF drain and fill. I'd buy a case (12 quarts) of the exact correct Toyota ATF specified in your manual and then do 3-4 apprx three quart drain and fills. Jack the car up and drain the AT via the drain plug in the AT pan. Then get the car level and refill the ATF with approx 3 quarts of new fluid back to full level on ATF dipstick (by adding ATF via the dipstick opening). Then drive the car around for 15-30 minutes to insure it goes through all gears. Then let the car cool down for a couple of hours and repeat the process. Or do it once a day for 4 days, or split it over 2-4 weekends, waiting period does not really matter. After you have performed the D&Fs the AT will have most of its ATF refreshed and you should be good to go for another 30 k miles at which point I'd do another 1 to 3 ATF drain and fills (how many times determined by how the fluid looks).
Last edited by Jabberwock; 11-17-17 at 03:36 PM.
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Carheart (11-17-17)
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#8
There is no way you are going to cause any negative issue with your AT by doing a simple 3 quart ATF drain and fill. I'd buy a case (12 quarts) of the exact correct Toyota ATF specified in your manual and then do 3-4 apprx three quart drain and fills. Jack the car up and drain the AT via the drain plug in the AT pan. Then get the car level and refill the ATF with approx 3 quarts of new fluid back to full level on ATF dipstick (by adding ATF via the dipstick opening). Then drive the car around for 15-30 minutes to insure it goes through all gears. Then let the car cool down for a couple of hours and repeat the process. Or do it once a day for 4 days, or split it over 2-4 weekends, waiting period does not really matter. After you have performed the D&Fs the AT will have most of its ATF refreshed and you should be good to go for another 30 k miles at which point I'd do another 1 to 3 ATF drain and fills (how many times determined by how the fluid looks).
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Carheart (11-17-17)
#9
Lexus Champion
Also bear in mind that the 2001 transmission does not use the "Life-time" fluid. It should be changed out occasionally or under certain driving conditions - every 60K miles.
Besides, the repair manual says...
Besides, the repair manual says...
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Carheart (11-17-17)
#10
I happen to agree here. If you want to feel better, a one time drain and fill with approximately 3 quarts of the the appropriate fluid should most likely do no harm. Small actions can usually make small changes. No harm here. It's only if you try to get all the old fluid out with fresh new fluid are you going into unknown territory.
#11
Racer
I'd be extremely careful when it comes to your next move. You already mentioned that the car shifts smoothly and you mentioined you think the fluid looks dark and possibly smells burnt. Before doing another thing.. you have one major thing in your favor. Your car shifts as it should. Go to a shop you trust (not necessarily Lexus) and ask them to inspect your fluid. If you had mentioned your car is not shifting correctly.. that is another story and you would have no choice to to change the fluid. Here you have a high mileage car that by changing the fluid and by changing all of the fluid, you might very well end up with a car that won't shift or even move! The varnish that has built up over time might be the only thing holding your transmission's clutches from slipping. Changing transmission fluid (unless you are the original owner) might be a throw of the dice... be careful my friend. Do yourself a favor and reread the post from Johnhav430. It might be very relevant. You want to do the right thing, but it might not necessarily go that way. If it were me? I'd leave well enough alone until I had a problem which you might not ever have. Good luck and let us know how it works out.
#13
Super Moderator
iTrader: (6)
The differential and brake fluids would be other candidates for fluid replacement if these have not been done.
Toyota has outlined how-what-when the service intervals are for the particular car be that Type IV or WS. Bear in mind what Toyota's definition of "lifetime" actually is.
Toyota has outlined how-what-when the service intervals are for the particular car be that Type IV or WS. Bear in mind what Toyota's definition of "lifetime" actually is.
#14
Moderator
There are certainly anecdotal data points about folks not maintaining their AT and when they finally do a fluid change (well after the ATF has clear signs of breakdown), the AT fails shortly thereafter. Most of these stories seem to be associated with an owner taking it to a shop that did a "power flush" on the AT using a machine that replaces all the ATF fluid under pressure. The power flush process reputedly can push wear particles and particulate from clutch packs into passages and clog them causing AT issues and possible failure. A normal manual ATF pan drain and refill does not use this process.
Despite the anecdotes floating around about not changing ATF fluid, if I personally acquired a high mile car with possibly original (or long over due to be changed) dirty brown burnt smelling AT fluid, I'd immediately perform the 3-4 D&F process likely at 1 week intervals, adding 3-4 quarts of new fluid each time and by significantly (but gently) refreshing the ATF fluid I'd feel confident that I was extending the useful life of my AT. No way I'd leave the burnt dirty fluid in my AT and just hope for the best.
Despite the anecdotes floating around about not changing ATF fluid, if I personally acquired a high mile car with possibly original (or long over due to be changed) dirty brown burnt smelling AT fluid, I'd immediately perform the 3-4 D&F process likely at 1 week intervals, adding 3-4 quarts of new fluid each time and by significantly (but gently) refreshing the ATF fluid I'd feel confident that I was extending the useful life of my AT. No way I'd leave the burnt dirty fluid in my AT and just hope for the best.