Transmission Oil Change By Cooler Disconnect

[rx300leo]

I would like to thank everyone who gave me advice on my previous post "RX300 Oil Cooler". Today I change the transmission oil by disconnecting the return line from the oil cooler. Special thanks to TunedRX300 for the procedure technique. There was one surprise on this task. When I came to the local Toyota dealer he said that T-IV is in short supply in our area as all Lexus owners are buying it ( I was really encouraged by his comment). So, I was able to get 8 last bottles.

When I drained oil from the transmission pan and the transfer box I got 5 quarts, then I filled it with 4 quarts, disconnected the return from the oil cooler, and started the engine. I got the reddish fluid after I drained approximately 1.7 quarts. With this method I obviously worried that having 8 quarts may not be very safe to drain a lot and was watching carefully for the color change.

I was a little dissapointed that at least 2 something quarts of old oil were still hiding somewhere, but was glad I had enough to replaced drained oil.

Next time I do transmission oil job I will think if I will go with this method (for ~2 additional quarts) or will do just drain from the pan and transfer box. It will take just no time.

Beinng under the car I looked at the front and rare differential. My 15/16 wrench was too thick to grab the drain plug of the front differential. I will need to get a new wrench for it and get the gear oil pump.

Would you please advise on the pump and may be on the wrench.

Thank you.

[mikey00]

I was wondering if this method would be effective when I first heard about it. Without knowing the flow pattern of the fluid I thought you may be just pumping clean fluid out the cooler line. Being that you did get an additional 1.7 qts of dirty fluid out, I guess I was only partially right. AWD holds 9.67 qts, you are left with 3 qts of old fluid. Maybe thats why the professional flush machines use 16 qts. Of course if you used 16 qts with your method it may be just as complete as a professional flush.

I think I will stick with a drain and fill getting out 5 qts, but I can see where some may prefer this method to get out the additional 1.7 qts.

[TunedRX300]

I would like to thank everyone who gave me advice on my previous post "RX300 Oil Cooler". Today I change the transmission oil by disconnecting the return line from the oil cooler. Special thanks to TunedRX300 for the procedure technique. There was one surprise on this task. When I came to the local Toyota dealer he said that T-IV is in short supply in our area as all Lexus owners are buying it ( I was really encouraged by his comment). So, I was able to get 8 last bottles.

When I drained oil from the transmission pan and the transfer box I got 5 quarts, then I filled it with 4 quarts, disconnected the return from the oil cooler, and started the engine. I got the reddish fluid after I drained approximately 1.7 quarts. With this method I obviously worried that having 8 quarts may not be very safe to drain a lot and was watching carefully for the color change.

I was a little dissapointed that at least 2 something quarts of old oil were still hiding somewhere, but was glad I had enough to replaced drained oil.

Next time I do transmission oil job I will think if I will go with this method (for ~2 additional quarts) or will do just drain from the pan and transfer box. It will take just no time.

Beinng under the car I looked at the front and rare differential. My 15/16 wrench was too thick to grab the drain plug of the front differential. I will need to get a new wrench for it and get the gear oil pump.

Would you please advise on the pump and may be on the wrench.

Thank you.

Glad you get more ATF out. I forgot to mention that you can also drain out old ATF from in the cooler itself but I think you may do the obvious by opening up the return line. This method is actually posted on Amsoil's web site. See step 13 in page 2

http://www.amsoil.com/faqs/ATF_and_Filter_..._Procedures.pdf

Have you tried to shift gears when the car is running, or just left it in "p"?

The front differential drain plug is the hardest to get off. I used 15/16 Craftsman open wrench and patiently wedge it to catch the drain plug. Toyota does not leave any space so be careful not to strip the relative soft alloy plug in the process. You can buy a suction gun at Autozone for about $8-10, the type that has a clear plastic tube, dip the tube into your fresh gear oil to draw it in, get under the car and pump it into the fill plug.

You need 10" extension and a 15/16 socket to loosen the fill plug, and make sure you can loosen it BEFORE you drain out the old fluid.

Rear differential for AWD uses 10mm fill and drain plugs, you can use L shaped allen wrench or a craftsman socket with 10mm hex end.

[rx300leo]

I would like to thank everyone who gave me advice on my previous post "RX300 Oil Cooler". Today I change the transmission oil by disconnecting the return line from the oil cooler. Special thanks to TunedRX300 for the procedure technique. There was one surprise on this task. When I came to the local Toyota dealer he said that T-IV is in short supply in our area as all Lexus owners are buying it ( I was really encouraged by his comment). So, I was able to get 8 last bottles.

When I drained oil from the transmission pan and the transfer box I got 5 quarts, then I filled it with 4 quarts, disconnected the return from the oil cooler, and started the engine. I got the reddish fluid after I drained approximately 1.7 quarts. With this method I obviously worried that having 8 quarts may not be very safe to drain a lot and was watching carefully for the color change.

I was a little dissapointed that at least 2 something quarts of old oil were still hiding somewhere, but was glad I had enough to replaced drained oil.

Next time I do transmission oil job I will think if I will go with this method (for ~2 additional quarts) or will do just drain from the pan and transfer box. It will take just no time.

Beinng under the car I looked at the front and rare differential. My 15/16 wrench was too thick to grab the drain plug of the front differential. I will need to get a new wrench for it and get the gear oil pump.

Would you please advise on the pump and may be on the wrench.

Thank you.

Glad you get more ATF out. I forgot to mention that you can also drain out old ATF from in the cooler itself but I think you may do the obvious by opening up the return line. This method is actually posted on Amsoil's web site. See step 13 in page 2

http://www.amsoil.com/faqs/ATF_and_Filter_..._Procedures.pdf

Have you tried to shift gears when the car is running, or just left it in "p"?

The front differential drain plug is the hardest to get off. I used 15/16 Craftsman open wrench and patiently wedge it to catch the drain plug. Toyota does not leave any space so be careful not to strip the relative soft alloy plug in the process. You can buy a suction gun at Autozone for about $8-10, the type that has a clear plastic tube, dip the tube into your fresh gear oil to draw it in, get under the car and pump it into the fill plug.

You need 10" extension and a 15/16 socket to loosen the fill plug, and make sure you can loosen it BEFORE you drain out the old fluid.

Rear differential for AWD uses 10mm fill and drain plugs, you can use L shaped allen wrench or a craftsman socket with 10mm hex end.

I started shifting gears when I connected the oil cooler line back and had nearly refilled (just below cold marks) transmission.

Thank you for the tips on differentials. I will check the wrench at Sears. I read your previous posts and you mentioned you used a synthetic gear oil. Was there any reason to change? Or you did not want to get to that nusty drain plug more frequently?

[TunedRX300]

Synthetic gear oil is 75w90, it is still GL-5 just slightly different weight, I like to get low viscousity oil at low temp since it flows better. Remember flow lubricates. Synthetic also reduces foaming, tiny bubbles increase the temperature, which is one of the major killers for gears. I choose Mobile 1 because it is more widely availiable, have higher vicosity index and lower kinetic vicosity number @ 40C over Amoil, only cost me a little over $8 at Autozone. 1 liter for front, and slightly less than 1 liter for the rear.

You can visit Mobil 1's web to get Mobil's claimed advantage, just take it with a grain of salt because it is partially for marketing.

http://www.mobil.com/USA-English/Lubes/PDS...t_LS_75W-90.asp

Double check with Amsoil to verify Mobil 1's claims. You will see Amsoil recommends 50K change for severe driving, 100K for normal driving. 100K is nice - Yes, I would hate to open that drain plug again and I am not going to pay Lexus $200 for this.

http://www.amsoil.com/storefront/fgr.aspx

Last, pershaps you already know that Toyota outsource gear oil. Toyota may not choose the best gear oil since only DIYer really care what is in the differential anyway.

http://www.clublexus.com/forums/showthread.php?t=194850

[rx300leo]

Synthetic gear oil is 75w90, it is still GL-5 just slightly different weight, I like to get low viscousity oil at low temp since it flows better. Remember flow lubricates. Synthetic also reduces foaming, tiny bubbles increase the temperature, which is one of the major killers for gears. I choose Mobile 1 because it is more widely availiable, have higher vicosity index and lower kinetic vicosity number @ 40C over Amoil, only cost me a little over $8 at Autozone. 1 liter for front, and slightly less than 1 liter for the rear.

You can visit Mobil 1's web to get Mobil's claimed advantage, just take it with a grain of salt because it is partially for marketing.

http://www.mobil.com/USA-English/Lubes/PDS...t_LS_75W-90.asp

Double check with Amsoil to verify Mobil 1's claims. You will see Amsoil recommends 50K change for severe driving, 100K for normal driving. 100K is nice - Yes, I would hate to open that drain plug again and I am not going to pay Lexus $200 for this.

http://www.amsoil.com/storefront/fgr.aspx

Last, pershaps you already know that Toyota outsource gear oil. Toyota may not choose the best gear oil since only DIYer really care what is in the differential anyway.

http://www.clublexus.com/forums/showthread.php?t=194850

Did you have any issues mixing the synthetic gear oil with left offs of regular gear oil, when you changed it for the first time?

[monarch]

My 15/16 wrench was too thick to grab the drain plug of the front differential.

All the nuts and bolts, drain and fill plugs, etc. of a Toyota / Lexus are METRIC sizes

[rx300leo]

My 15/16 wrench was too thick to grab the drain plug of the front differential.

All the nuts and bolts, drain and fill plugs, etc. of a Toyota / Lexus are METRIC sizes

You are correct, it should be. So, it is loose 24mm for front differential. I could not get a good grip on a drain plug with my 24mm open wrench either. Need to get a tighter wrench.

[TunedRX300]

My 15/16 wrench was too thick to grab the drain plug of the front differential.

All the nuts and bolts, drain and fill plugs, etc. of a Toyota / Lexus are METRIC sizes

From my experience, it is the "claws" of your regular Craftsman wrench that are too thick, not the size of the opening. Toyota did not leave enough room to fit either a socket or a open ended wrench because the drain plug is carved into the metal differential "ball".

rx300leo:

I have no issues to have tiny amount of dino GL-5 to mix with Synthetic. Another member posted he changed to Mobil 1 synthetic, drove around for 1 month and drain & fill again. I did not since both Syn and traditional oil complies with API GL-5 oil standard and do not want to risk to strip the drain bolt. Just do what you feel comfortable, I don't believe it is an issue you should lose sleep over. Again, that is just me.

[monarch]

Is there enough clearance for a 24mm 6 point box end wrench wrench? I bought some of these 6 point box end wrench at Sears the other day although they were out of stock on the 24 mm size. 6 point wrenches fit nuts tightly and securely.

[TunedRX300]

Is there enough clearance for a 24mm 6 point box end wrench wrench? I bought some of these 6 point box end wrench at Sears the other day although they were out of stock on the 24 mm size. 6 point wrenches fit nuts tightly and securely.

No, if I remember it right, a circular carving out of the differential "ball" houses the drain plug, but those six points of the plug are touching the circle, making it impossible for me to attach a regular craftsman socket or open wrench. Perhaps a thin wall socket will fit better.

[TunedRX300]

Just post this RX300 Transmission Photo DIY as a courtesy for those who wants to drop the transmission pan, disconnect the cooler line, and change the transmission filter.

Even though there is no replacement for sound transmission design, it is highly recommendated to do preventative maintenance, DIY or at Lexus dealership.

[Grumpa72]

All the nuts and bolts, drain and fill plugs, etc. of a Toyota / Lexus are METRIC sizes

Of course Toyota uses metric sizes. But, some metrics are so close that SAE can be used when needed. I, too, used SAE on the front differential bolt but I am thinking of going to Home Depot/Lowes, buying 15/16" and grinding down the outside edges a bit. I had a bear of a time trying keep from chipping up the front diff housing. Why would Toyota/Lexus make things so tight that you can't use standard metric sockets or other tools in that spot?

Gary

If you use this Amsoil technique of pouring in the new transmission fluid as the old is being pumped out, don't you run the risk of mixing some new in with the old as it is being moved through the black magic part of the transmission? Secondly, if this procedure is as good as it seems, why can't you buy, say, 8 quarts of Dextron to use as a flush. Remove the transmission cooler line, run the engine and replace the Toyota fluid with Dextron as it is being pumped out. Then, replace the Dextron with Toyota fluid using the same procedure. Where is the flaw in this thinking?

Gary

'05 330

[TunedRX300]

If you use this Amsoil technique of pouring in the new transmission fluid as the old is being pumped out, don't you run the risk of mixing some new in with the old as it is being moved through the black magic part of the transmission? Secondly, if this procedure is as good as it seems, why can't you buy, say, 8 quarts of Dextron to use as a flush. Remove the transmission cooler line, run the engine and replace the Toyota fluid with Dextron as it is being pumped out. Then, replace the Dextron with Toyota fluid using the same procedure. Where is the flaw in this thinking?

Gary

'05 330

The transmission pump draws from the fluid from the pan and use fresh ATF to push old ATF out. There is no mixing (unlike drain and fill 2x or 3x in a row).

Dextron ATF is not spec-ed for RX, I used Amsoil (please no debate here) since it supports Toyota T-IV and many Lexus owners have used it and reported no problems. You can choose OEM fluid or Mobil ATF 3309, but I have no experience with Mobil outside their M1 engine oil.

The other drawback of pouring ATF in the dipstick or suck it in with the other cooler line is you need a third person to take care of it. I was already busy with guiding the cooler return line to the transmission to the drain pan with one hand, checking fluid color with another hand.