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I need step by step instructions to flush 2005 lexus ls 430 transmission fluid
Therr is none it is a sealed transmission that you need to have hooked up to a flush machine as well as a scan tool hooked up to make sure the transmission temp is correct for fill and flushing.
Therr is none it is a sealed transmission that you need to have hooked up to a flush machine as well as a scan tool hooked up to make sure the transmission temp is correct for fill and flushing.
I have scan gauge to read transmission temp but i would like instructions on step by step
I have scan gauge to read transmission temp but i would like instructions on step by step
Flushing involves using a pump to force transmission fluid through the cooler line. There is a good chance that you may push debris into small passages in the valve body and ruin your transmission. A better way to change ATF is to perform the drain-and-refill. I did 3 drain-and-refill in the same day. Here is a link on how I did it... https://www.clublexus.com/forums/ls-...-04-ls430.html
If I'm not mistaken Toyota's official procedure is a drain/fill only. That chart showed how much original remains after a drain/fill...I think it went 55%, 31%, 19%, or close. And everyone incl. my indie said stop at 3. Maybe wait at least a year before 4.
There was a very in-depth video about Toyota sealed trannies, where Toyota even has different lengths of straws so you can drain/fill at various temps.
Even more interesting was someone recently went 300k and they said they didn't do drain/fills, so one almost has to wonder if it's really needed. Common sense says absolutely, nothing lasts forever, but we seem to have examples where it was never touched...
Flushing involves using a pump to force transmission fluid through the cooler line. There is a good chance that you may push debris into small passages in the valve body and ruin your transmission. A better way to change ATF is to perform the drain-and-refill. I did 3 drain-and-refill in the same day. Here is a link on how I did it... https://www.clublexus.com/forums/ls-...-04-ls430.html
I don't know why my numbers are different, but I got this here. also, my indie agreed with these numbers and stated going past #3 is of diminishing benefit and really not necessary. Said come back in a year if you really want to do a 4th drain/fill
Dunno if you feel like sitting through this entire video, but I did find it fascinating how complicated the drain/fill has become without a dipstick...it also helped me to visualize a little better what my indie was telling me while we were standing under my car...
Plenty of varying DIY methods to accomplish this. The right one is the one that works best for you. The sensors in the trans will monitor the temp for you, the PDF shows how to do this with a jumper wire on the OBD port, I'd be interested to see if your scan gauge is consistent with the sensor built into the trans.
Plenty of varying DIY methods to accomplish this. The right one is the one that works best for you. The sensors in the trans will monitor the temp for you, the PDF shows how to do this with a jumper wire on the OBD port, I'd be interested to see if your scan gauge is consistent with the sensor built into the trans.
Here's the Service Manual PDF
AND THANKS for the pdfs to one of my concerns were the accuracy of scan gauge tool also but so far so good......
Don't be afraid to flush the tranny contrary to popular belief. I've done it using the cooler lines on my 400 twice at 120k and 190k, plus I did it on the 430 not long after I got it with 120k.
https://www.clublexus.com/forums/ls-...e-at-home.html
To flush or not to flush? Unfortunately, there isn't a one-size-fit-all answer.
ATF serves 3 functions in the transmission: 1) As lubricant to lubricate all moving parts, 2) As coolant to remove heat mostly from the torque converter, and 3) As hydraulic fluid to operate shifting via the solenoids and to provide clamping power for the number of clutches.
The general Rule-of-thumb is to inspect the existing ATF. If you see small particles in the ATF, or if it smells burnt - do not flush. The burnt smell indicates that the clutch plates had been slipping and the excessive heat had already damaged the clutch materials. Small heat fractures on the clutch plate can fail catastrophically and shatter. Also, new ATF tends to worsen the slippage and accelerate the deterioration. In my case, my old ATF does not smell burnt.
Refer to the sketch below, the ATF filter sits slightly off of the bottom of the pan, such that it will not pick up the sludge accumulated there. Draining the pan will eliminate the sludge while flushing will circulate the sludge through the filter and clogging it. So at a minimum, I would drop the pan and replace the ATF filter after a flush, if this were my car. I did not want to drop the pan and replace the ATF filter.
Recall from high school chemistry lab... when you add salt to water, at first the salt completely dissolves in the water, but as you continue to add salt, at some point the water becomes saturated and can no longer dissolve the salt, and some salt begins to precipitate. Any more salt added from this point forward will just settle to the bottom. Likewise, the ATF circulate fine particles around and after 12 years, it becomes saturated and the excess fine particles precipitated to the bottom as sludge. If we add new ATF, which is not saturated with fine particles, to the sludge as in the case of "flushing", the new ATF will dissolve the sludge at the bottom of the pan and carry the fine particles to the filter clogging it. On the other hand if we drain the sludge first before adding new ATF, we would be draining out the sludge and will end up with significantly less fine particles we will deposit onto the filter.
Unlike the motor oil filter where the oil pump is located upstream of it, motor oil is "pushed" into the filter, and if the filter is clogged, a little built-in bypass valve in the filter allows oil to bypass the filter material and continue to flow unfiltered. Check out Post #37 on HERE to see how the motor oil filter bypass valve works. The ATF pump "pulls" ATF through the filter and if it is clogged, the pump is starved. Without sufficient ATF, shifting solenoids may not work properly, and insufficient clamping power for the clutches will cause slippage (and eventually burnt the ATF). This can take years to develop and by the time you realize your clutches are slipping or find burnt smelling AFT, it's too late!
Finally, the ATF upon leaving the ATF pump is routed to two paths via pressure regulators. One path leads to the valve body where the shifting solenoids are, and the other path goes to the torque converter and onward to the cooler. If you "flush" the transmission by using the transmission ATF pump through the cooler lines, keep in mind that portion of the ATF recirculates within the transmission without going to the cooler. So "flushing" does not get all old ATF out.
All that being said, it is a personal choice on which way you want to proceed and how much risk you are willing to accept.
Last edited by rkw77080; 02-15-18 at 11:07 AM.
Reason: Added link to motor oil filter bypass valve
To flush or not to flush? Unfortunately, there isn't a one-size-fit-all answer.
ATF serves 3 functions in the transmission: 1) As lubricant to lubricate all moving parts, 2) As coolant to remove heat mostly from the torque converter, and 3) As hydraulic fluid to operate shifting via the solenoids and to provide clamping power for the number of clutches.
The general Rule-of-thumb is to inspect the existing ATF. If you see small particles in the ATF, or if it smells burnt - do not flush. The burnt smell indicates that the clutch plates had been slipping and the excessive heat had already damaged the clutch materials. Small heat fractures on the clutch plate can fail catastrophically and shatter. Also, new ATF tends to worsen the slippage and accelerate the deterioration. In my case, my old ATF does not smell burnt.
Refer to the sketch below, the ATF filter sits slightly off of the bottom of the pan, such that it will not pick up the sludge accumulated there. Draining the pan will eliminate the sludge while flushing will circulate the sludge through the filter and clogging it. So at a minimum, I would drop the pan and replace the ATF filter after a flush, if this were my car. I did not want to drop the pan and replace the ATF filter.
Recall from high school chemistry lab... when you add salt to water, at first the salt completely dissolves in the water, but as you continue to add salt, at some point the water becomes saturated and can no longer dissolve the salt, and some salt begins to precipitate. Any more salt added from this point forward will just settle to the bottom. Likewise, the ATF circulate fine particles around and after 12 years, it becomes saturated and the excess fine particles precipitated to the bottom as sludge. If we add new ATF, which is not saturated with fine particles, to the sludge as in the case of "flushing", the new ATF will dissolve the sludge at the bottom of the pan and carry the fine particles to the filter clogging it. On the other hand if we drain the sludge first before adding new ATF, we would be draining out the sludge and will end up with significantly less fine particles we will deposit onto the filter.
Unlike the motor oil filter where the oil pump is located upstream of it, motor oil is "pushed" into the filter, and if the filter is clogged, a little built-in bypass valve in the filter allows oil to bypass the filter material and continue to flow unfiltered. The ATF pump "pulls" ATF through the filter and if it is clogged, the pump is starved. Without sufficient ATF, shifting solenoids may not work properly, and insufficient clamping power for the clutches will cause slippage (and eventually burnt the ATF). This can take years to develop and by the time you realize your clutches are slipping or find burnt smelling AFT, it's too late!
Finally, the ATF upon leaving the ATF pump is routed to two paths via pressure regulators. One path leads to the valve body where the shifting solenoids are, and the other path goes to the torque converter and onward to the cooler. If you "flush" the transmission by using the transmission ATF pump through the cooler lines, keep in mind that portion of the ATF recirculates within the transmission without going to the cooler. So "flushing" does not get all old ATF out.
All that being said, it is a personal choice on which way you want to proceed and how much risk you are willing to accept.
Thanks for such a concise technical explanation of the transmission and the part the fluid plays. I think this should end all discussions about the necessity of "flushing" based on people's experience and feelings without technical data to substantiate their claims.
02-13-18, 12:10 AM
