Transmission Fluid and filter change. (1 Viewer)

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The PO left a factory transmission filter and gasket in the vehicle. Do you think it wise to do this? I have heard good and bad on this. I will not be using any special thermometer tools or anything like that. If I did it I would drain while warm, replace the filter and gasket and replace the amount I took out. This would be a shade tree mechanic repair. I could flush 3 quarts a couple of times first to save the new filter before replace the filter the last time I guess. What are you guys thoughts and any precautions if I do this? It has 154,000 miles and not sure it has ever been done. Didn't see anything about it on the Lexus web site. Have heard good and bad about doing it with over 100,000.
 
I did this on my GX at 137K this past winter. Here are my recommendations:

1. Do drop the pan and replace the "filter" (really more of a strainer). The reason high-mileage transmission fluid changes can cause issues is that they can disturb sediment buildup at the bottom of the pan and circulate it through the rest of the transmission, so you have to remove the sediment before adding fluid and disturbing things. My GX had a nice film of sediment on the bottom of the pan, which I thorughouly removed with brake cleaner and a rag. The filter/pan drop is actually pretty easy (maybe <1 hr total with the remove and replace). After dropping the pan, put the same amount of clean fluid in the pan as you removed (more on this later).

2. Do the complete fluid exchange from the front of the vehicle (at the transmission cooler), all at once, rather than the partial flush. To do this you'll need to:
a) disconnect the in hose from the cooler, attach it to some clear plastic hose, and route it to a bucket/bottle that holds at least 2 quarts with markings. Put plastic over your fenders/paint so you don't get fluid on them.
b) have a helper start the engine, put a foot on the brake, and shift thru P-R-N-D-N-R-P until 2 quarts is pumped out into your bucket/bottle.
c) remove the out/return rubber hose from the cooler, attach some clear plastic hose to the rubber hose, and route it to an elevated funnel.
d) pour 2 quarts into the funnel; this will then flow back to the pan through the cooler return line. Note this may take a long time as the fluid is viscous - I'm talking like 10 minutes or so for 2 quarts. I saw a YouTube video where the guy made this a lot quicker with compressed air and a fluid jug.
e) repeat the process until you have 100% clean fluid coming out of the in line from the cooler, but not less than 15 quarts total added (including what you already put in the pan). My fluid noticeably cleaned up by 13 quarts and was totally clean at quart 15.

3. Once the fluid is exchanged check the transmission level using the plug on the bottom of the pan once the transmission is at operating temp ranges prescribed by the FSM, with the GX on level ground (check the frame rails with a level to verify, adjust as needed) and the engine running. I did this using a WiFi OBD2 reader and Torque, which pulls the actual transmission temperature from the ECU/PCU (WiFi reader is $30, Torque is $5, note you need to program in the equation to get the Toyota trans temp, which is easy and the equitation is listed on multiple Toyota forums). There is also a FSM procedure to jump pins on the OBD2 port; I tried this and could not get it to work. If the fluid level is too high, it will pour out of the fill plug, simply put the plug back in after it stops pouring. If it is too low, add new fluid through the fill plug at the rear right side of the transmission until it pours out, again with the engine running in park.

This is a messy, slow job, but it is not hard or technical. I would set aside around 4 hours, but less if you can figure out how to add the fluid back in using compressed air. If you can change spark plugs you can tackle this job. I strongly recommend the flush method above as you get 100% new fluid in the transmission and you get all of the sediment out of the bottom of the pan, rather than mixing new fluid with dirty fluid and disturbing sediment on the pan bottom. FWIW, I used Valvoline MaxLife HM fluid from Wal-Mart (claims to be compatible with Toyota WS, and is much cheaper). My old fluid was black at 137k. The GX shifts great (and it shifted great before).
 
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I did this on my GX at 137K this past winter. Here are my recommendations:

1. Do drop the pan and replace the "filter" (really more of a strainer). The reason high-mileage transmission fluid changes can cause issues is that they can disturb sediment buildup at the bottom of the pan and circulate it through the rest of the transmission, so you have to remove the sediment before adding fluid and disturbing things. My GX had a nice film of sediment on the bottom of the pan, which I thorughouly removed with brake cleaner and a rag. The filter/pan drop is actually pretty easy (maybe <1 hr total with the remove and replace). After dropping the pan, put the same amount of clean fluid in the pan as you removed (more on this later).

2. Do the complete fluid exchange from the front of the vehicle (at the transmission color), all at once, rather than the partial flush. To do this you'll need to:
a) disconnect the in hose from the cooler, attach it to some clear plastic hose, and route it to a bucket/bottle that holds at least 2 quarts with markings. Put plastic over your fenders/paint so you don't get fluid on them.
b) have a helper start the engine, put a foot on the brake, and shift thru P-R-N-D-N-R-P until 2 quarts is pumped out into your bucket/bottle.
c) remove the out/return rubber hose from the cooler, attach some clear plastic hose to the rubber hose, and route it to an elevated funnel.
d) pour 2 quarts into the funnel; this will then flow back to the pan through the cooler return line. Note this may take a long time as the fluid is viscous - I'm talking like 10 minutes or so for 2 quarts. I saw a YouTube video where the guy made this a lot quicker with compressed air and a fluid jug.
e) repeat the process until you have 100% clean fluid coming out of the in line from the cooler, but not less than 15 quarts total added (including what you already put in the pan). My fluid noticeably cleaned up by 13 quarts and was totally clean at quart 15.

3. Once the fluid is exchanged check the transmission level using the plug on the bottom of the pan once the transmission is at operating temp ranges prescribed by the FSM, with the GX on level ground (check the frame rails with a level to verify, adjust as needed) and the engine running. I did this using a WiFi OBD2 reader and Torque, which pulls the actual transmission temperature from the ECU/PCU (WiFi reader is $30, Torque is $5, note you need to program in the equation to get the Toyota trans temp, which is easy and the equitation is listed on multiple Toyota forums). There is also a FSM procedure to jump pins on the OBD2 port; I tried this and could not get it to work. If the fluid level is too high, it will pour out of the fill plug, simply put the plug back in after it stops pouring. If it is too low, add new fluid through the fill plug at the rear right side of the transmission until it pours out, again with the engine running in park.

This is a messy, slow job, but it is not hard or technical. I would set aside around 4 hours, but less if you can figure out how to add the fluid back in using compressed air. If you can change spark plugs you can tackle this job. I strongly recommend the flush method above as you get 100% new fluid in the transmission and you get all of the sediment out of the bottom of the pan, rather than mixing new fluid with dirty fluid and disturbing sediment on the pan bottom. FWIW, I used Valvoline MaxLife HM fluid from Wal-Mart (claims to be compatible with Toyota WS, and is much cheaper). My old fluid was black at 137k. The GX shifts great (and it shifted great before).
 
Thanks for the awesome write up. I believe I can do it but I have heard good and bad about it. That's the only fluid that hasn't been changed since I have owned it . i will keep my fingers crossed.
 
Thanks for the awesome write up. I believe I can do it but I have heard good and bad about it. That's the only fluid that hasn't been changed since I have owned it . i will keep my fingers crossed.
No problem, it's doable for a DIYer, and documented in a few YouTube videos as well. I did make a giant mess on my shop floor, and my wife got a bit tired of shifting through the gears, but it was cheaper than a shop and it's good to have a clean transmission for the next 60-90k. If you do this you might want to post some pictures as folks ask about the transmission fluid change a lot. I didn't take any pics when I did mine.
 
There’s no need to drain warm if you are dropping the pan. When you do drop the pan clean it out and clean the magnets with brake cleaner and place the magnets back where they were.

you should also buy the crush washers for the drain, fill, and overflow plugs.

doing the procedure to get the correct fluid level is not difficult and more foolproof than replacing the same amount that was drained. There’s no guarantee that the amount that’s in there currently is correct.
 
There’s no need to drain warm if you are dropping the pan. When you do drop the pan clean it out and clean the magnets with brake cleaner and place the magnets back where they were.

you should also buy the crush washers for the drain, fill, and overflow plugs.

doing the procedure to get the correct fluid level is not difficult and more foolproof than replacing the same amount that was drained. There’s no guarantee that the amount that’s in there currently is correct.
It's a good idea to do both. I replaced the same amount of fluid and it ended up a bit under-filled. Either the transmission was low to start with or I got a bit off on the measurements. Doing the replace/refill to the same amount should, however, get it pretty close to full.

I also forgot to mention the magnets, I concur the should be removed and cleaned. I also replaced the crush washers.
 
It's a good idea to do both. I replaced the same amount of fluid and it ended up a bit under-filled. Either the transmission was low to start with or I got a bit off on the measurements. Doing the replace/refill to the same amount should, however, get it pretty close to full.

I also forgot to mention the magnets, I concur the should be removed and cleaned. I also replaced the crush washers.
Thanks, do you have a Toyota part # for the crush washers?
 
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