rkw77080

According to the repair manual, the 04-06 LS430 transmission dry-fill capacity is 11.5 US quarts, and a drain-and-refill will replace 3.2 US quarts of ATF.



I want to determine the optimal number of drain-and-refill (D&R) that yields the best value for the money. Here’s what the math says…

To start, the original ATF contains 11.5 US quarts of old ATF and no new ATF, or 0% concentration of new ATF.

For D&R #1, I will drain 3.2 US quarts of old ATF and replace with 3.2 US quarts of new ATF, so the resulting concentration is 27.8% new ATF.

For D&R #2, I will drain 3.2 US quarts of the 27.8% mixture, which contains 0.9 US quarts (27.8% of 3.2) of new ATF and 2.3 US quarts of old ATF. Adding back 3.2 US quarts of new ATF will give me 5.5 US quarts of new ATF in the mixture (two 3.2 US quarts I added so far, minus the 0.9 US quarts I drained out). The resulting concentration for D&R #2 is 47.9% new ATF.

For D&R #3, I will drain 3.2 US quarts of the 47.9% mixture, which contains 1.5 US quarts (47.9% of 3.2) of new ATF and 1.7 US quarts of old ATF. Adding back 3.2 US quarts of new ATF will give me 7.2 US quarts of new ATF in the mixture (three 3.2 US quarts I added so far, minus the 0.9 and 1.5 US quarts I drained out). The resulting concentration for D&R #3 is 62.4% new ATF.

Beyond D&R #3, I will be throwing out more new ATF than old, and yield 10.5% or less improvement.The chart below summarizes the ATF concentration after each D&R. I will take the car for a short drive, after each D&R, to thoroughly mix the new and old ATF before proceeding to the next D&R.

rkw77080

The repair manual recommends that ATF level must be adjusted at specified temperature range, namely between 115 degF and 130 degF. I wanted to confirm the significance of this recommendation, so I put some ATF in a measuring class at 80 degF, and then pop it in the microwave for a minute and see if the level would change. My experiment is not precise, but it proves the point that ATF expands quite a bit with temperature. See for yourself...

JffGRY706

what is your current mileage?
any previous service on your transmission?
a peek at condition of fluid replaced would be appreciated.
you seem to know more about these cars than anyone else and information received is always appreciated. that and that you are also in Texas where it is very hot makes your input more valuable to me

rkw77080

I have decided that three drain-and-refills (D&R) will give me the best return for my money. I will do the three D&R's all at once with a short drive between each refill to thoroughly mix the old and new ATF. I have 10 US quarts of ATF WS on hand. I went to store and picked up a couple of 1-gallon pitchers (milk jugs will work as well), and a hand pump... I'm all set to go.




Note that after the first D&R, you will be throwing away some new ATF during the D&R #2 (0.9 quarts), and D&R #3 (1.5 quarts). In other words, you are only keeping 7.2 quarts out of the 9.6 quarts you put back into the transmission.

I will report back after I'm done.

Gronemus

I would appreciate any photos of the area where you are adding the fluid back into the transmission. Also interested in how your pump works and how much fluid is left in the pump/lines.

Thanks!

toddmorr

wow, i'm surprised at how much difference in volume the increased temperature creates. But I guess Toyota warned us via the repair manual.

I'd drive for longer than just a brief drive between drain/fills though.....reason being, if transmission fluid cleans as well as they say, I'd be inclined to let the fresh cleaning agents do their thing for several hundred miles.

bradland

I did a couple drain and fills about a month ago. I used my Mityvac 7201 fluid pump / extractor to refill on the first one. The Mityvac is awesome and I love it dearly but I found it easier, for this procedure, to refill with some clear plastic tubing and a funnel. Buy about 3 foot of tubing and attach a funnel at the top. Snake it down from the engine compartment where a trans dipstick would be and ultimately into the fill hole. Much easier to manage when you get close to the desired level.

Thanks for the pic pic showing the volume expansion. I've always been curious about that...

Fixman

I second that. I would keep the D&R at 500 mils apart. And go for 4 D&R.

rkw77080

Here is a quick write-up on how I drained and refilled (D&R) my 04 LS430 transmission, and how I adjusted the ATF level.

Step 1: Jack up the front end of the car and put it on jack stands.

Step 2: From under the car, remove the two bolts and transmission case cover.


Step 3: Remove the refill plug.



Step 4: Loosen the overflow plug but do not remove. This will make things easier when the overflow plug is removed later to adjust the ATF level, which is done while the car is off the jack stands, and is parked on a level surface.




IMPORTANT NOTE: Make sure that you can remove the refill plug to add new ATF, and that you can remove the overflow plug to perform the final ATF level adjustment.

Also make sure you have the following supplies on hand:





Step 6: Using a second 1-gallon pitcher, pour in the same amount of new ATF.

Step 7: Use the funnel and clear tubing to transfer new ATF from the 1-gallon pitcher down into the transmission from the engine bay.



Step 8: Replace refill plug. NOTE: Never run the engine with the refill plug open.

Step 9: Start the engine and move the shift lever through entire gear range to circulate the ATF.

Step 10: Take the car off of the jack stands and take it out for a short (2-3 minutes) drive to thoroughly mix the new ATF with the remaining old ATF.

Step 11: Repeat the D&R steps described above two more times.

Step 12: After the third D&R, take the car off of the jack stands and park it on a level surface.

Step 13: Start the engine and allow it to idle. The proper ATF temperature range for level adjustment is between 115°F and 130°F. I used my infrared temperature gun to aim at the transmission pan to measure ATF temperature.



Step 14: Once the ATF reaches 115°F, remove the overflow plug with the engine idling.

NOTE: Never open the overflow plug when the engine is not running.

Since I have been draining warm ATF and replacing with cold ATF, my transmission was slightly over-filled after D&R #3.




I allowed the ATF flow to slow to a trickle, I re-installed the overflow plug. Torque specification for the overflow plug to 15 ft⋅lbf; and for the refill plug is 29 ft⋅lbf.

CAUTION: There is a chance that your ATF level maybe low to start with, in which case you will not see overflow of ATF as described in Step 14. If so, you will have to reinstall the overflow plug, stop the engine (never stop the engine with the overflow open), add more cold ATF through the refill hole, reinstall the refill plug (never start the engine with the refill open), start the engine and allow it to idle, then repeat Step 14.

js058515

RKW always delivers....what a blessing to the forum.

rkw77080

I have 152,000 miles on the car now. The last time I did a drain-and-refill was around 100K. I didn't think the old ATF was in very bad shape then. To be honest, I could have gone another 100K this time, and was debating to do less than the three D&R as originally planned. I went ahead and did three D&R anyway just so I can cross that item off my To-Do list.

Unfortunately, I did not see your post until after I cleaned up and disposed of the old ATF. Sorry! By appearance and color, it did not change much.

I know the ATF serves 3 functions in the transmission:
1. It is a lubricant - the ATF provides lubrication to all the moving parts
2. It is a coolant - the ATF circulate to remove heat from the hot spots such as the torque converter and gears, to minimize localized overheating
3. It is hydraulic fluid - the ATF is a hydraulic fluid to aid gear-shifting via solenoids

Overfilling seems to be detrimental to the ATF. During normal operation, the ATF level should be well below any moving parts. Otherwise, the moving parts will churn and cause the ATF to foam. Air bubbles within the ATF significantly degrade its ability to perform as a hydraulic fluid causing poor shifting. Worse yet, the ATF pump struggles to provide adequate ATF flow (as coolant) due to its foamy condition. This causes localized overheating (burnt ATF) and can cause permanent damage to the transmission overtime.

2KHarrier

Nice write up and explanation. I would hope this is liked to the DIY page. Again, nice job RKW!

rkw77080

I did not use the hand pump for this DIY, instead, I decided to use a funnel connected to the clear tubing (that came with the pump) to pour the ATF from the engine bay. Between D&R's, I tucked the funnel/tubing aside in the engine bay and left the lower end hanging free near the refill hole.

rkw77080

Some minor, but important details about the Refill plug and the Overflow plug...

1. Refill plug: Be sure to install the refill plug before you run your engine, or ATF can spray onto the exhaust pipe and potentially cause a fire.

2. Overfill plug: The overflow tube is designed for the proper ATF level, at the specified temperature range, UNDER NORMAL OPERATING CONDITIONS, which means that the engine (and thus the ATF pump) is running, and the A/C is OFF. Do not open the overflow plug when the engine is not running because without circulation, all of the ATF is drained back into the pan, and the ATF level is much higher than the overflow tube. I suspect the ATF flow will change slightly over time due to wear of the pump, and pluggage of the ATF filter. Lower flow rate can potentially raise the ATF level somewhat.

tallcaguy

Thanks, this is really helpful. My indy did D/F#1 (probably cold, drained, same amount replaced). Dealer did D/F#2 (by temp). Said indy overfilled by 1/2 quart. Maybe just expansion. In the picture, guesstimating that expanded level is 125 ml which is almost 5%. I did 1k between D/F's. Should probably do a 3rd. Have the same IR heat gun so I can check ATM temp. Just curious. Thanks. Your input and expertise are much appreciated!