Enz

iTrader: (1)

I didn’t know that my wife’s 2010 RX350 AWD has the optional transmission cooler, this shows how much I know about her car :-( mainly because it’s been serviced at the dealership and it had an extended warranty so I never really had to do any work on it. Anyways the tranny has never been serviced at 100K and I want to do a fluid exchange from the cooler return line. I did a lot of research on multiple drain and fill because I assumed it didn’t have the optional cooler but I just found out this morning that it has one.

I’ve done the cooler return line fluid exchange on my RX300 and 4Runner. You use a LOT of ATF but it's cherry red after the procedure!

The U660F has a fluid capacity of 7 quarts, so I figured 10? or 12? quarts should be enough for this procedure or do I need to get more?

Maxlife or Toy WS? I was originally going to use WS but I think I changed my mind again and will use ML since I will be using a lot more fluid, maybe 14 quarts to make sure I get rid of as much of the old fluid.


Drain point option #1

Got this photo from TN and it shows the return line from the radiator for a U660E FWD, would it be the same for a U660F AWD? I think it is from the diagram from parts.lexus.com for my VIN it shows from what I can tell the return line is closer to the driver side.

Part 32941 is listed as “hose, oil cooler inlet, no.1”

The rest of the hoses are only labeled transmission oil cooler hose.

IF I don’t get a confirmation then I guess, I’ll have to pull both hoses and see which one spits out fluid when I run the engine which will be the supply.


Return hose for U660E FWD and also U660F AWD?


Preferred/Drain point option #2

Has anyone done it from the hose coming from the optional oil cooler (32910)? Not sure how hard it is to get to the cooler (32910), hopefully through the fender liner??? and pull the lower hose and attach a 3/8” clear hose and drain from there, marked by GREEN circle. Or even on the other end of that hose where it attached to the tranny.

Any guides out there on this option?

I want to do it from there since this will replace the old fluid from the optional cooler too. I figured the flow of the fluid is as shown below with the red arrows. Hopefully it is correct.

TIA!




ATF flow and Preferred/Option #2 drain point in Green

Enz

iTrader: (1)

And since I couldn't find all the info in one place, I thought I would post it here:

6 speed U660E and 660F fluid capacity: 7 quarts

Operating Temp: 104-113F


Inspection plug/drain crush washer pn: 90430-12008 or 90430-A0002

torque bolt 29 ft-lbs, 6mm allen, plastic tube 7 in-lbs., 6mm allen


Side fill plug crush washer pn: 90430-18008

torque bolt 36 ft-lbs, 24 mm


splash guard 2x10mm bolts

clips: 90467-07043

Clutchless

I have a Magnefine filter on the supply hose on my Sienna, (same as the RX) and you can get to both hoses from underneath the car if you remove the trim panel.
I have done a lot of cooler line flushes on older cars with dipsticks, as I presume you also have done. It should be the same, just followed by the Toyota fluid level check procedure afterwards.

One more thing is if you have the tow package and the engine oil cooler rubber lines have not yet been replaced with the steel ones, it should be done. If they fail it will spew out all the oil by the time the oil light comes on. If they are seeping, Lexus has an extended warranty coverage, but if they explode and you blow the engine, good luck getting a new engine from them. The new part is under $100 and you could replace it yourself.

https://www.clublexus.com/forums/rx-...eplacment.html

Enz

iTrader: (1)

Thanks for confirming this and the tip on the replacing the oil cooler lines! I finally found a video last night that was close enough, its for a 2015 HL so I wasn't 100% sure if its the same though the optional cooler looked the same.

Since I really didn't find a DIY on this for the RX350, here's mine below.

I don't like to drain and wait for the bubbles, this might starve the tranny. What I do differently is I fill what I drain from the plug + 1 quart. Then I drain and fill 2 quarts at a time from the hose. Repeat until all the dirty fluid has been pushed out and I get cherry red. Then I do it one or two more times depending on how dirty the fluid was originally and when the last D&F was done.

So if I drained 2.5 qts from the plug, I would put back 3.5 then drain 2 quarts from the hose. Keep on doing 2 quart D&Fs. This way you are only 1 quart low after you let out 2 qts. from the hose and not starving the tranny at any time. The last fill will not be 2 quarts but only 1.25-1.5 quarts for trannys with dipsticks, It's easier to add than to remove excess fluid with the older trannys w/dipsticks. For the rx350 probably will add 2 and let it just overflow out of the tube at operating temp.

I also use a Bluetooth ODBII reader instead of the jumper cable or temp gun. They are cheap and paired with the Torque pro app you can get a lot of info on your vehicle on you phone and its more accurate than a temp gun since you're getting data from the tranny temp sensor and not measuring the temp of the casing. Plus you can have you phone with you underneath the car and watch the temp go up instead of waiting for the dash light to flash then hurrying up to get underneath your car.

Lastly, I drain using a clear 3/8" hose and directly into a milk jug with 1/2 quart increments marked on the side. This way you don't have to transfer the ATF from your drain pan into a measuring container which gets messy sometimes. I used a measuring cup filled with 1/2 quart of water at a time for accuracy but you really don't need to be that accurate for this car (you have to be on trannys with dip sticks without overflow tubes) since you are overfilling the last fill anyway and let the excess drain out the overflow tube at temp. Also keep track of the amount you've drained and then filled every time! It's easy to go through the ATF you have, you don't want run out of ATF and have to run to the store to get more!

NOTE: One big advantage of a fluid exchange over multiple drain & fills is that the old fluid is pushed out as you replenish the tranny with new ATF. There is less mixing of old and new ATF as compared to a D&F.


Preferred drain point: optional ATF cooler return line to tranny

afpj

Did you find a built-in PID for tranny temp using torque pro? I don't see one. There's some older threads about making your own PID but the readout is a little wonky sometimes.

Enz

iTrader: (1)

Not sure what the PID is but I used transmission temperature method 2 (or 1) not hooked up right now so I can't confirm.

AlgoTrader

I did this to my 3RX just after I bought it in July 2019 (when it had 66K miles). I did a trans pan drop first and replaced the screen (hint - loosen the driver's side engine mount and the one pan bolt that is covered by the cradle can be accessed).

I have the tow package and the external ATF cooler. I used the exit port on the cooler for getting the old ATF out.

I've done the "shadetree mechanic ATF flush" procedure before on my old 'murican traditional dipstick tube, real-wheel-drive vehicles, so I'm familiar with the the whole process. I have the Aisin U660F (AWD version of the U660E), and the procedure is more complicated for these "sealed" or standpipe type trans than the older, "dipstick tube" type trans.

Please note that this is a RISKY procedure, as you need to pump in new fluid as the old fluid is pumped out. If you let the level in the trans drop too much, you could cause the trans to suck air and possibly damage it. I ended up shutting off the motor halfway through the refill, so I could stay ahead of the fluid being pumped out. I used 10 quarts of Toyota WS-ATF. My research on the interwebs into a cheaper alternative did not give me confidence in Maxlife. The only alternative I thought might be acceptable was Aisin manufactured WS
https://www.google.com/search?client...WS%29+JWS-3324
but, at the time, genuine Toyota WS on amazon was only $92, so not much cheaper so I just went with Toyota WS. I see that WS is more expensive now, and with shipping, around $30 more for 10 qts than the Aisin WS.

Setting the level was difficult, as this was my first "sealed" (standpipe) type trans. I used the method that uses the jumper wire and playing with the shifter until the inst cluster gives you the signal that the trans temp is good for checking the level.

73K miles now, no issues at all.

Non

Let us know how is the ML working for you. I'm curious if you'll see any difference/improvement over the old, used fluid, after a complete flush.

When I do my drain-and-fills, I do not notice any difference after, everything feels the same. Maybe because my car is lower mileage, or because I use Toyota WS.


.

Enz

iTrader: (1)

Non,
Sorry for the late reply, this is my wife's car so I don't really drive it that much so I didn't feel any major difference. Perhaps slightly quicker/crisper shifting? You know what they say - every time you make a modification it feels that your car is faster, every time! As for my other vehicles, I've always maintained them regularly so I guess the ATF doesn't have time to degrade that much to feel the difference.

AlgoTrader

update: 78k miles, no problems

Enz

iTrader: (1)

Thanks for the update! BTW, how did the filter look like? I dropped the pan on my 4Runner and replaced the filter (more like a mesh screen) and the old one looked great. The ATF is very high in detergents so I figured crap won't form into clumps and gunk up the filter, it's more for larger particles that hopefully would drain out with the ATF or get stuck on the magnets. So from then on, I skipped dropping pans and replacing filters unless its a required maintenance specified by the manufacturer.

AlgoTrader

In my case, the filter is fully enclosed in a plastic housing, so I'm not sure.
Side note: my ATF was dark, but not black.

According to Scotty Kilmer, the automatics (not including CVT) made in Japan, and especially Aisin manufactured trans have less of a problem with the clutch disk friction material wearing off and floating around in the ATF then their comparable 'murican made counterparts. I'm referring to the wet clutches that Automatics use.

Asian or 'murican, or whatever make, it's still advisable to do a flush at around 60K miles the first time, and some regular interval after that. I plan on every 30 to 40K miles. I might change the trans filter again at around 150K assuming I still have my RX by then (strong possibility I will keep this car another 9 years or more).

I do the same procedure and intervals with my 'murican made cars, though they are far easier to flush, as they are from the 90's, so they have dipstick tubes and are not "sealed" type trans.

AlgoTrader

Another tip I have learned since doing my flush: Buy the tool that consists of a plug that screws into the refill port of the U660E (or U660F), that has a hose attached to it. If you can get a funnel on that hose, and hang up the hose next to the car, outside of the driver's side wheel well, this serves the same purpose as the dipstick tube that older automatic trans have. Makes refilling far easier.

Enz

iTrader: (1)

Which one did you get? I thought about those but I thought it might slow the fill process since the displaced air won't have an easy path to get out. Plus I have dedicated pumps, funnels, hoses, etc... for every type of fluid so I don't get cross contamination. They just go into their own bags after use.

AlgoTrader

I haven't purchased one yet, as I've been moving, and I won't need to do another flush until my RX gets to 100k miles.