450h differential fluid
Rookie
Joined: Jan 2021
Posts: 27
Likes: 11
From: DE
Like golferjack, I just went through the 2021 Warranty and Service book. There is no scheduled maintainance required for the differntial on the hybrid. It only says on Page 71:
Rear Differential
Oil Check level and condition of oil and inspect the rear differential assembly case for signs of leakage. (The rear electric motor/generator does not require periodic maintenance.) Any service that requires inspecting or replacing rear differential oil should be performed by a qualified technician following procedures in Lexus service and repair publications. Please refer to the important safety precautions on the inside front cover of this booklet.
Seems to imply that you only change it if it is leaking. Keep in mind that motor only kicks in when there is slippage in the front drive wheels. Reviews I read on the 350 and 450 say the 350 has a better AWD system because you can lock it into AWD, an option you cannot do with the CVT using 450h. So I can imagine the 350 with the auto transmission and a transfer case (not on the hybrid) has a larger differential and sees more "wear" than the hybrid independent motor in the back which is controlled by the computer and not the driver.
My Jeep dealer told me that lifetime fluids mean they last the life of the car where the cost ot repair (transmission) exceeds the value of the car. He said it with a wink and smile, but that's what manufacuter's mean by lifetime.
Rear Differential
Oil Check level and condition of oil and inspect the rear differential assembly case for signs of leakage. (The rear electric motor/generator does not require periodic maintenance.) Any service that requires inspecting or replacing rear differential oil should be performed by a qualified technician following procedures in Lexus service and repair publications. Please refer to the important safety precautions on the inside front cover of this booklet.
Seems to imply that you only change it if it is leaking. Keep in mind that motor only kicks in when there is slippage in the front drive wheels. Reviews I read on the 350 and 450 say the 350 has a better AWD system because you can lock it into AWD, an option you cannot do with the CVT using 450h. So I can imagine the 350 with the auto transmission and a transfer case (not on the hybrid) has a larger differential and sees more "wear" than the hybrid independent motor in the back which is controlled by the computer and not the driver.
My Jeep dealer told me that lifetime fluids mean they last the life of the car where the cost ot repair (transmission) exceeds the value of the car. He said it with a wink and smile, but that's what manufacuter's mean by lifetime.
Last edited by Millarduck; Jan 11, 2022 at 09:04 AM.
Driver School Candidate
Joined: Apr 2022
Posts: 1
Likes: 0
From: RI
Pit Crew
Joined: Jan 2020
Posts: 101
Likes: 12
From: QQ
There's no such thing as lifetime fluid
Both torque split Transmission ( with planatary setup) and eCVT( like a rear diff) need the fluid replaced at 60 K normal driving with type WS fluid . 4 litres for front and 2 litres for rear . Simple to do ........................ The Car Care Nut has a good video explaining it and hes a master tech at toyota !
https://www.youtube.com/watch?v=I1fP-RKsqG0
https://www.youtube.com/watch?v=I1fP-RKsqG0
Intermediate
Joined: Jan 2018
Posts: 360
Likes: 42
From: Victoria, Australia
If the fluid is lifetime, why then does it turn so dark after extended usage? I believe this is an indication that the fluid is breaking down due to heat. I would expect the breakdown from continuous heat and cold cycles is detrimental to the lubricity of the fluid. Not sure why the USA and Canada vehicles do not specify a fluid change interval, but on the Australian service booklet, it does specify a fluid replacement for the RX450h on the rear section of the booklet under the severe usage section.
Last edited by tempestv8; Oct 21, 2023 at 04:22 PM.
Do 450H Have Front Diff?
im asking this because i told the advisor to do trany and diff fluid drain and fill and he ask me is my car have awd and i say yes then he say u want to do front diff too? i say sure. im asking here because i saw the tranny fluid thread no1 talks about the front diff only the tranny and diff. let me know thanks
Rookie
Joined: Jan 2021
Posts: 27
Likes: 11
From: DE
If the Lexus service advisor asked you if your 450h is AWD (they all are), then, run don't walk away. Never go back because they hired a moron as a service advisor it makes you wonder who is taking wrench to the car.
Racer
Joined: Aug 2012
Posts: 1,796
Likes: 226
From: GA
From Edmonds:
2016 Lexus RX 450h models
The 2016 Lexus RX 450h is a five-passenger midsize crossover SUV available in front-wheel- and all-wheel-drive versions.
https://www.edmunds.com/lexus/rx-450...ive%20versions.
Intermediate
Joined: Jan 2018
Posts: 360
Likes: 42
From: Victoria, Australia
Not sure why that service advisor made a distinction between transmission and front diff, as if these are two separate things on the 4th gen RX450h. The CVT gearbox (transmission) happens to also be the front differential, as it is effectively one unit. Which means that there is not two separate lots of fluids. The service advisor is making it sound like there are two separate fluid changes, one for the tranny, and one for the front diff. But it is the one and same thing.
For the rear differential, that's a separate fluid change there. At least in Australia, all 4th gen RX450h are AWD. The only 4th gen RX in Australia which has just front wheel drive is the RX270 (pure ICE, not hybrid)
For the rear differential, that's a separate fluid change there. At least in Australia, all 4th gen RX450h are AWD. The only 4th gen RX in Australia which has just front wheel drive is the RX270 (pure ICE, not hybrid)
6th Gear
Joined: Apr 2021
Posts: 6
Likes: 1
From: NJ
Hey...Here in Northeast USA with 2016 RX450h...
Today, I went to my usual local Toyota dealership for an engine oil change, transmission drain/fill and front and rear diff oil changes. The tech(Master Diagnostic tech) called me to the vehicle to show me that there is no front diff oil change needed because it shares the same oil as the eCVT....I was lost because I thought they were two separate parts and two separate oil plugs/ports...Maybe I completely misunderstood.....I only do minor work on both my RX's and previous vehicles. No DIY oil changes for me. The other is a 2016 RX350.
Today, I went to my usual local Toyota dealership for an engine oil change, transmission drain/fill and front and rear diff oil changes. The tech(Master Diagnostic tech) called me to the vehicle to show me that there is no front diff oil change needed because it shares the same oil as the eCVT....I was lost because I thought they were two separate parts and two separate oil plugs/ports...Maybe I completely misunderstood.....I only do minor work on both my RX's and previous vehicles. No DIY oil changes for me. The other is a 2016 RX350.
Rookie
Joined: Dec 2024
Posts: 40
Likes: 12
From: KY
Rear Diffferential Fluid
There is no "rear differential oil"
There is no way to "check its condition" without actually draining it. To what - fair warning. You MUST open filler plug first as some, as it is VERY torqued, could not, while they opened drain plug and ended with only towable vehicle.
Rear PSD is smaller copy of the front PSD.
In BOTH PSDs, ATF is ONLY splash lubricant and bears NO hydraulic function. Hence, it is nowhere warn out as fast, as regular ATF in regular transmission.
Sure, you are welcome to replace it. It's 2.2 qrt rear, drain and fill and 4.2 qrt front, drain and fill. I care not what manual says, I had identical power train - Highlander Hybrid - done twice and I know the real life capacities. TCH also takes 4.2 qrt. Also had it done twice.
If you can lift vehicle level, there is no point in taking it to dealer and paying them mucho dinero for very simple drain and fill job. All it takes is quality L shaped 10mm hex wrench, cheat pipe for it, or 10mm hex socket with breaker bar, some vessel to catch the fluid and either long tube with funnel to feed ATF from the top in or fluid pump to pump it in to overflow.
CAR MUST BE LEVEL.
There is no way to "check its condition" without actually draining it. To what - fair warning. You MUST open filler plug first as some, as it is VERY torqued, could not, while they opened drain plug and ended with only towable vehicle.
Rear PSD is smaller copy of the front PSD.
In BOTH PSDs, ATF is ONLY splash lubricant and bears NO hydraulic function. Hence, it is nowhere warn out as fast, as regular ATF in regular transmission.
Sure, you are welcome to replace it. It's 2.2 qrt rear, drain and fill and 4.2 qrt front, drain and fill. I care not what manual says, I had identical power train - Highlander Hybrid - done twice and I know the real life capacities. TCH also takes 4.2 qrt. Also had it done twice.
If you can lift vehicle level, there is no point in taking it to dealer and paying them mucho dinero for very simple drain and fill job. All it takes is quality L shaped 10mm hex wrench, cheat pipe for it, or 10mm hex socket with breaker bar, some vessel to catch the fluid and either long tube with funnel to feed ATF from the top in or fluid pump to pump it in to overflow.
CAR MUST BE LEVEL.
Rookie
Joined: Dec 2024
Posts: 40
Likes: 12
From: KY
9th Gear
Joined: Nov 2024
Posts: 9
Likes: 1
Did both eCVT and rear diff on my 2017 RX450H last month (on my own not dealership). Both take Toyota ATF WS fluid.
89K miles on the car. eCVT was never changed. The fluid that came out of the eCVT made me think this should have been done 25K miles earlier. Extremely dark. Either way glad I did both.
89K miles on the car. eCVT was never changed. The fluid that came out of the eCVT made me think this should have been done 25K miles earlier. Extremely dark. Either way glad I did both.
Rookie
Joined: Dec 2024
Posts: 40
Likes: 12
From: KY
Did both eCVT and rear diff on my 2017 RX450H last month (on my own not dealership). Both take Toyota ATF WS fluid.
89K miles on the car. eCVT was never changed. The fluid that came out of the eCVT made me think this should have been done 25K miles earlier. Extremely dark. Either way glad I did both.
89K miles on the car. eCVT was never changed. The fluid that came out of the eCVT made me think this should have been done 25K miles earlier. Extremely dark. Either way glad I did both.
