Welcome to CL and congratulations on your new to you RX. I have done many drain and fills on my RX and on all of them used MAG 1 full synthetic low viscosity multi vehicle ATF. It now shifts better than new and it has almost 80,000 miles. Save your money and buy a 6 pack of it at Amazon for $30 instead of the Amsoil ATF.
I also highly recommend you spend the time to read this entire thread to learn exactly how to do the drain and fill. It also contains useful photos.

I know you probably never heard of MAG 1, but it is one of the many brands made by Warren Distribution, one of the largest and most well regarded private label oil brand manufacturers around. They produce lubricants for everyone from Wal-Mart to their own brands Mag 1 and Gumout. Here is are lists of their brands and private label brands.

http://www.warrendistribution.com/brands

https://www.bobistheoilguy.com/forum...f-youre-intere

I will recap the highlights here since you are new.
I always do it with a cold car and the ATF the same temp as the fluid expands when hot.
There are 2 things in the drain hole. Both take a 6 MM Allen wrench.
Remove the drain plug and let it drain, when it stops stick your wrench back in the hole and remove the overflow tube and more fluid will drain. The total should be about 2.25 quarts.
Measure exactly how much drained out and put that much back in plus about 4 ounces.
The fill hole is reached by removing the driver side front wheel. There is a flap and the lower edge of the fender liner that covers the fill bolt You need a long funnel to pour fluid back in.
Be careful insalling the overflow tube, it does not need to be very tight as it is held in place by the fill plug, and being plastic is easily damaged.

 

Thanks for the info. I have two choices. One is a Lexus dealer that has the a BG PF5 to do a full fluid exchange or the other is a drain and fill. Any comments between the two?

 

Go with the BG if you can afford it and do not want to spend the time doing 3 drain and fills. That is what the local Toyota dealer used on my Nieces's 2010 ES350 which has the same transmission as the RX. Ask if they use WS fluid instead of BG fluid. The Toyota dealer was using WS in the BG machine.
They charged about $225, but also flushed the coolant and brake fluid at the same time so I got a package discount with a total price of about $500.
It shifted perfectly afterward and still does 2 years later.

 

If you do the drain & fills can you post what color and length the plastic level tube is?
Our 2012 does not have the factory tow package and it came with a red/30mm tube.

Will a car with the OEM tow package have more fluid drain out for a drain & fill compared to a non-tow package car?
An aux trans cooler would increase the volume of fluid in a system and I think the fluid in the cooler would drain into the trans sump when the engine is not running.
Do you remember what color your level tube is?
I haven't measured the size of the trans pan, but if it's 12"x12" and a green/38mm tube was installed the amount of fluid in the pan would be about .75qt. more than with the red tube.

 

rababich - In response to your questions, the owner's manual only states that FWD vehicles have a transmission capacity of 6.8 quarts and AWD vehicles a capacity of 7.0 quarts. There is no mention of the towing package cooler increasing capacity, although, in my opinion, it must increase it some. I recall from installing aftermarket transmission coolers on other vehicles that they typically list the amount of increased fluid capacity as that is a selling point and tells how large it is and how much more cooling it will provide. However, it probably does not increase the level of fluid in the pan as the increased fluid would be in the cooler and longer cooler lines. I know when installing aftermarket coolers before in automatic transmissions with dipsticks that no mention was made of changing how you measure the fluid on the dipstick, just that overall capacity would be a little bit larger. So I doubt you need to change your fluid level tube if adding an additional cooler.

I do not recall the color of the fluid level tube. I will pay attention next time I do a drain and fill.

 

I agree with everything.
I was just wondering if the tow package equipped cars have the taller level tube.
Also, was wondering if the replacement green/taller level tube I have is standard issue to cover both applications which would imply a little more fluid in the sump wouldn't hurt.
In all my past cars adding an aftermarket trans cooler did increase overall capacity a bit, but they were all Fords with dipsticks.
To check the trans fluid level in old Fords the engine is supposed to be idling.

 

I don't think the amount matters when checking as the level would be the same even if there is more fluid overall.

 

I'm surprised that the dealer has a BG machine, most if not all Lexus/Toyota dealers here in Ontario have a MOC ATF exchange machine, no matter the system is the same.
Make sure they use the Toyota WS fluid and NO additives, this is by far the most complete fluid exchange you can make.

 

Well after a lot of discussion with some local transmission shops and Toyota service tech's I am probably going with the standard drain and fill with WS fluid. Depending on the color of the first drain will determine how many I will do. I did get a Scan gauge II that reads ATF temp so might wait till it warms up and do the the other ones myself. There just was not enough users and data for me to switch to Amsoil and take that chance that I would not have problems later on.

When looking at the hitch today I found out that the wiring harness from the rear plug to the flat trailer connector was never installed so I believe it was used for a bike rack or cargo carrier and never used to tow a trailer. This would explain why the tow hook loops looked like they were never used.

I also was able to use a $250.00 scan tool and everything seems to check out with no codes found in the system. I also was able to get the PID codes for Distance (miles) at 40721 and Time (hours) at 1092 hours 15 Minutes. That averaged at 37.28 MPH so sounds about right.

It had 63,089 miles when I bought it so the codes must of been cleared around the 22,368 mark during a service check for some reason.

But overall everything looks great at this point. I will get back after the transmission drain and fill and let you know the results of the condition of the old fluid when it was drained.

I will also drain and fill the transfer case and rear differential using Amsoil Severe Gear 75W-90 gear lube.

Thanks everyone for all your help on this. I think with timely changes of the transmission fluid from now on should put me in good shape.

 

You could also look into Valvoline MaxLife ATF. My mechanic dropped the pan and changed the filter screen. I provided him with WS fluid. His opinion was that type of fluid wasn't the only good fluid available. After a lot of research on other toyota forums and bobistheoilguy, I came to the conclusion to start using Valvoline MaxLife. A lot of people have been using this fluid in their toyota transmissions with no issues. I don't recall the data but some think the MaxLife is a better fluid than WS. I did 4 drain and fills with MaxLife about 10 thousand miles ago. The transmission is shifting very smooth.

 

I also think that the Toyota WS is the best bet for our transmissions. Other fluids may also work, but maybe not.

Also, I think changing the fluid at around 60k miles is just perfect. I will change mine sooner proactively, but my mechanic says that the synthetic ATF in our cars really needs to be changed every 60k miles.

 

Yes it is hard to decide. I am still torn between the Amsoil and WS but I am only going to do a drain and fill multiple times.

 

Don’t think Toyota ws is synthetic.

 

No it isn't, but that doesn't mean that it's inferior in this application. Often synthetics are not compatible with some additives and so manufacturers have to go with non synthetic fluids.

 

If car is still under manufacturer's warranty, I say stay with WS to avoid warranty issues. If not under warranty, any WS spec ATF should do. I have Valvoline Max Life in all my Toyota products except the new RX350, and will not hesitate to replace oem ATF in it with Valvoline when warranty expires, at which point I will have done one ATF flush with WS.