UA80E / UA80F - Toyota/Lexus Direct shift 8 Speed

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The UA80E (2wd) / UA80F (AWD/4WD) found in later RX-350's and Toyota Highlanders is an 8 speed multi-lock-up transmission and it's considered "Sealed for life" with no serviceable filter and no dip stick. Just a tad over 8 quarts is required to do a full exchange and just over 3 quarts to to do just whats in the pan (if it had one). The transmission is emptied by taking out the #10 Hex bolt on the bottom of the transmission. Some fluid comes out and then you need a #6 long Hex to take out the plastic straw located inside the same hole to release the remaining fluid from the bottom of the transmission. It comes filled with Toyota WS fluid by default which can run at 200F regularly not towing. The only time they recommend a change is in Severe duty situation which then it should be changed at 100,000 miles (160,000km) - Yeah like that was going to happen. grin2 Once you have drained all the fluid you put the straw back in the drain hole just hand tight. Then fill the transmission using the WS bolt plug on the side of the transmission located behind a cover inside the drivers wheel well. This small cover is moved out of the way by removing the 2 bolts (10mm). It will take about 3 quarts. Fill until it spills out of the hole in the bottom where the straw is. You also need to press on the end of the transmission thermostat located just under the radiator. There is a hole in the skid shield. Press on the end of it with a flat screw driver and then insert a small pin to lock it in the open position. This is necessary as the external cooler is only open to the ATF fluid cooling circuit when the fluid is at higher temperatures. It is necessary to make sure the external cooler is also full of fluid when correctly refilling the transmission as per Toyota Tech Info procedures. Start the vehicle and put it in Drive with your foot on the brake for 10 seconds, then reverse for 10 seconds to fill the circuits with fluid. Then back in park. Then fill the transmission further until it spills out the straw again with the vehicle running still. Then with your scantool or Scangauge II with 4.42 software or higher and X-Gauge code for the Transmission Pan temperature. Wait until the fluid reaches 104F and reinstall the drain plug. Your transmission is now full to the correct level. Do not exceed 113F before putting the plug back in the bottom of the transmission or it will be under full. This temperature changes rather quickly in hot weather so be quick about it. This is has to be done with the body of the vehicle level off the ground so you will need jack stands for the rear and front of the vehicle to do it properly. It's also best to do it when the vehicle is cold because it will quickly heat the transmission fluid back up over the 104F really quickly thanks to the coolant to ATF heat exchanger. Simply removing fluid from the pan and pouring the exact same amount of fluid back into the transmission can have undesired consequences due to fluid expansion rates differing from Toyota WS official fluid and some other brand that meets this specification which is why it's best to fill and check using the procedure above. Toyota advises always using this method for refilling the transmission anyway. If anyone has this transmission and has questions about this change procedure feel free to send me a PM. I will tell you after having done this today on my UA80F transmission the Toyota WS fluid leaves a lot to be desired in terms of shift quality and I would highly advise using some other brand that meets the WS fluid specification. I chose Amsoil Fuel Efficient Vehicle formula which is meant to replace WS fluid, because I'm a fan of their transmission oils and have used them in the past with excellent results but there may be other quality manufacturers out there just as good. Sorry I didn't think to take pictures of the process but when I drain/refill again I will take pictures. cheers
 

StevieC

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It's not advisable. From what I read these transmissions are really fussy on precise fluid level to function properly. Too little and it makes noise and shifts poorly. Too much and it over heats and can cause damage because there isn't enough room for expansion. This fluid expands wildly which is why they only give you a 9 degree window to measure the fluid using their straw system. You are welcome to risk it but I wouldn't take the chance. It sounds a lot harder than it actually is. It does require a scan tool or scan gauge using 4.42 or higher software with X-Gauge programmed for Pan fluid temperature. (Again easier than it sounds)
 
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Good writeup - curious when you mentioned 8Q was cycled through. Draining the pan completely may give you no more than 4Q, did you do this procedure twice.
 
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Thanks for the tech write up. I am about to service our 2013 GS350 F Sport with 60K miles. I bought 6 quarts Idemitsu WS equivalent, which is Synthetic. Guess I am a little curious about the thermostat; not sure if it applies in a 2013. The 2013 uses the 6 speed; the 8 speed was used in 2014 forward except on AWD cars, if I am not mistaken. I will see what I can see. Thanks again.
 
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StevieC

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Originally Posted by MaximaGuy
Good writeup - curious when you mentioned 8Q was cycled through. Draining the pan completely may give you no more than 4Q, did you do this procedure twice.
I drained the pan and refilled then I took the line off coming from the Coolant to ATF heat exchanger that runs to the Thermostat (Easily accessed behind the cover you take off for the fill hole) and let it flow out here with the vehicle running while I poured in fresh ATF through the fill hole stamped "WS" on the bolt. I waited until I was over 8qt's to ensure I had exchanged it all and then followed part of the procedure above to make sure it was properly filled before sealing it back up.
 
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StevieC

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Originally Posted by JeffKeryk
Thanks for the tech write up. I am about to service our 2013 GS350 F Sport with 60K miles. I bought 6 quarts Idemitsu WS equivalent, which is Synthetic. Guess I am a little curious about the thermostat; not sure if it applies in a 2013. The 2013 uses the 6 speed; the 8 speed was used in 2014 forward except on AWD cars, if I am not mistaken. I will see what I can see. Thanks again.
Not sure... Next time I'm in my Toyota Tech Info account I will have a look regarding the Thermostat. The search feature on the TIS website sucks at best. With regards to the 8 speed it's fairly new and only offered in a handful of Vehicles. Later Camry's with the V6 offer it as well as far as I know.
 
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StevieC

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Originally Posted by KrisZ
Good write up and even though I don't own a Toyota I can appreciate the effort. It may also away some members to change the ATF instead of believing Toyota that the tranny is "sealed" for life. Also, kudos on chenging the original fill early thumbsup
cheers
 

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Update: So it has been many thousands of miles since the ATF change and it appears that the transmission has compensated for the new ATF with it's adaptive logic and the not so great low speed shifting has returned. It's jerky and abrupt at times and like it can't make up it's mind what gear to be in. Especially between 1st and 2nd gear when re-accelerating from slowing down or taking a corner at slower speeds without stopping first. Downshifts on the highway are also felt some of the time almost like there is a broken/worn engine mount. I decided to try the Manual "S" mode on the shifter and set it to S8 so that it will automatically shift up and down in this sportier manual mode. It's like a whole new vehicle and completely stops the nonsense that I was complaining about instantly. As soon as I take it out of the "S" mode it returns instantly back to this nonsense again so there is clearly a software revision that needs to be done to the normal shifting program as the "S" mode holds the gears longer on both the up-shifts and down shifts and briefly stops the acceleration for the shift to take place so it's not felt at all. Super happy I found that this works and I have written to Toyota about the problem in hopes they will issue a software fix for me and all the other folks complaining on the Toyota / Lexus boards about this new transmission and how terrible the shifts are at times. UA80E / UA80F. Thought I would update it here in case others are having similar problems. Steve
 
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Experience notchy feeling on 3-4 gears in Comfort mode on my MB. Once the Sport mode is turned on there is no gear hunting or slow speed indecisiveness. I guess will live with it and take it to the dealership if it becomes annoying - have a long way to go for expiration of powertrain warranty.
 

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Yeah I think it's because they are trying to cut the RPM's down as quickly as possible and it's so aggressive doing this it sacrifices smooth performance. It is quite annoying having to put it into "S" after driver and then pushing the shifter forward 3 times to up to gear 8 from the default 5 but at least there is a work around. Hopefully they issue a fix.
 
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I've been a lurker on BITOG for years, but joined today to reply to this post. I'm a moderator on SiennaChat and technical contributor to the Highlander section of ToyotaNation, both AutoGuide vehicle forums. There have been a lot of issues/complaints about the new UA80 E/F Direct Shift 8AT from Aisin, and I thought I'd tie some things together for both audiences. First off, our collective thanks to StevieC for the fluid change write-up. I'll put a link on the other boards to this thread, as it's by far the most complete description I've found to date. About your complaints on transmission performance: There have been a few TSB's that you might review, and possibly act upon. I'm hoping the moderators on this board won't mind some links to work I've already done. https://www.toyotanation.com/forum/...-2018-8spd-tranny-new-tsb-12-2018-a.html https://www.toyotanation.com/forum/...ny-ecu-tcu-program-update-available.html Finally, I have added a composite diagram that shows some details that might be interesting to the audience, gathered from the SAE, Aisin, a rebuilder parts supplier, and others.

UA80 Composite.JPG
 
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Originally Posted by Fibber2
I've been a lurker on BITOG for years, but joined today to reply to this post. I'm a moderator on SiennaChat and technical contributor to the Highlander section of ToyotaNation, both AutoGuide vehicle forums. There have been a lot of issues/complaints about the new UA80 E/F Direct Shift 8AT from Aisin, and I thought I'd tie some things together for both audiences. First off, our collective thanks to StevieC for the fluid change write-up. I'll put a link on the other boards to this thread, as it's by far the most complete description I've found to date. About your complaints on transmission performance: There have been a few TSB's that you might review, and possibly act upon. I'm hoping the moderators on this board won't mind some links to work I've already done. https://www.toyotanation.com/forum/...-2018-8spd-tranny-new-tsb-12-2018-a.html https://www.toyotanation.com/forum/...ny-ecu-tcu-program-update-available.html Finally, I have added a composite diagram that shows some details that might be interesting to the audience, gathered from the SAE, Aisin, a rebuilder parts supplier, and others.
welcome That is a very awesome and informative post thumbsup
 

StevieC

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welcome and thanks for the Info. I have unfortunately traded the vehicle because I couldn't put up with it. I lost complete confidence in the unit for the long term and with the miles I drive I couldn't take a chance on a break down. If anyone on the other forums has questions about the oil change procedure I'd be happy to answer them. Just send me a PM here. cheers
 
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First off, thanks for the warm welcome gentlemen! I'm sorry to hear that your adventure with the Toyota ended this way. I'm sure they will get it right (eventually).
 

StevieC

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Originally Posted by Fibber2
First off, thanks for the warm welcome gentlemen! I'm sorry to hear that your adventure with the Toyota ended this way. I'm sure they will get it right (eventually).
I haven't written the brand off because all OE's have their woes from time to time. (Supported by the fact that I own a Chrysler and they have had their fair share of woes). I just needed to step into something I knew was proven and reliable while Toyota figures out the 8-speeds. I certainly was impressed by the service at my local dealership where I bought the Toyota so that alone would have me considering them again in future, I think I would just do more in-depth research of the model and choose something that has an engine/transmission that has been out a while and proven.
 
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We just purchased a 2019 awd Highlander LE v6 and were concerned about the transmission issues on the early 8 speed transmissions. I'm here to say wow, the Highlander we purchased was build in December of 2018 and it shifts very smooth, with almost undetectable shifts when accelerating slowly. Overall with 400 miles on the clock so far it's very enjoyable to drive.
 
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StevieC

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Originally Posted by robd
We just purchased a 2019 awd Highlander LE v6 and was concerned about the transmission issues on the early 8 speed transmissions. I'm here to say wow, the Highlander we purchased was build in December of 2018 and it shifts very smooth, with almost undetectable shifts when accelerating slowly. Overall with 400 miles on the clock so far it's very enjoyable to drive.
I hope it continues for you. Mine started out that way and then loosened up and was terrible. I had 16,000km (10K miles) when I got rid of it. My build date was June/18
 
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