DaSyce

iTrader: (3)

Anyone have this replaced by the dealer? Did you change transmission fluid at the same time?

golferjack

What are you refering to? There is no differential and the ICVT never needs a change.

DaSyce

iTrader: (3)

2017 RX450h owners manual page 588. Page has a section for rear differential (rear electric motor). Also states fluid capacity is 1.9 qt, Toyota ATF WS. Seems pretty specific.

Separate section addresses transmission eCVT fluid.

All fluids breakdown.

golferjack

It is not a differential like in a rear wheel drive vehicle, just like the ecvt is not like other manufactures cvts. The name cvt conjures up visions of belt drive transmissions and maintenance implications. The same can be said for the poor choice of a name for the rear motor, which does not need servicing..

DaSyce

iTrader: (3)

Honestly not trying to argue.

I’m just a little surprised to hear that the factory service guides are inaccurate about serviceable parts. As the 2017 RX450H Maintenance Schedule also prints that that the rear differential is a serviceable item. Requires fluid inspection ever 30k, and recommends replacement if vehicle is used for towing.

DaSyce

iTrader: (3)

Since its not a typical transmission (planetary CVT), and Lexus likes to sell the idea of a lifetime fluid, have any owners replaced / serviced the WS ATF fluid in a hybrid?

I would like to have it replaced at 45k. I would expect the highest degree of wear to occur early in the units service life. I can only imagine the next highest degree of wear would occur due to a viscosity breakdown of the fluid.

I would expect that replacement of the fluid would serve as preventative maintenance. Thoughts?

TechNut

Those "lifetime lubricant" conversations seem to be fighting words on various subforums here on Club Lexus. I am not a mechanic so I really know nothing about modern transmissions (CVT or otherwise), but it just doesn't feel right to assume it has lifetime fluid. Aside from the idea of the fluid gradually breaking down, it will also accumulate particles from normal wear. From just a pure logic perspective, I would think anything with gears washed in lubricating fluids is going to have wear (otherwise the lubricating fluids wouldn't be necessary), which implies the lubricating fluids are going to have metal particles suspended within as the fluid ages. Those particles along with the gradual breakdown in viscosity suggest the notion of "lifetime fluids" is questionable. So yes, I agree with your leading question you used to create the poll - even though my "opinion" is based on pure conjecture as I really don't have the knowledge to reach an informed conclusion.

Anyway, my 450h is only a few months old so it will be a long time before I have to worry about this, but I have wondered if owners of hybrid transmissions should have the same concern as those vehicles with standard transmissions. Look forward to hearing where this discussion goes...

golferjack

The ecvt is like the old rear end differential years ago. Those differentials were never changed, but at some point in time the mechanic would remove the plug at the midpoint of the differintial and stick a finger in to see if there was grease. I the finger was not wet, then he would add grease. That was the totality of maintenance.

ukrkoz

https://www.clublexus.com/forums/hyb...my-rx400h.html

Same principle difference for your year except that the front fill plug - TO BE RELEASED FIRST! - is on the wheel side of transmission.
You do not have CVT. Toyota called it CVT for registration purposes in the US. ATF is SPLASH LUBRICANT only and, as such, is no subject to hydraulic stress and wear. You surely welcome to replace it, I did mine on HiHy at 50K miles just for the ****s and giggles, but I like doing such things and have car lift. It is super easy drain and fill. Otherwise, it is indeed a lifetime fluid. I know of a guy who owns TCH with all original, closing on 300 000 miles.

nicnac

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 !

golferjack

Replace it if you want, but it is a life time fluid, and never needs replacing. Look at what this guy did at 270000 miles

https://www.rav4world.com/threads/20.../#post-2714597

nicnac

Theres always one !!!!!!!!!!! Its not a case of what you can get away with on cars but what is prudent to do to keep a car in the best mechanical condition to lesson the mechanical wear ..you base your ascertion on a post by a guy who obviosly can grow oranges in his pocket and wont spend $200 dollars at a dealership !
Engineering is not up for grabs by forum "professional engineers "who know the square root of FA ,.....................

golferjack

Go get 'em, but it is still a life time fluid.
Here is what the manual says:
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.

Transmission Fluid
The transmission and transmission
fluid are a completely sealed unit.
Therefore, periodic checks and
replacement of the transmission
fluid are not required, and there
is no dipstick on the transmission.
Inspect the transmission/front
differential assembly case for signs
of leakage. (The front electric motor/
generators do not require periodic
maintenance.) Any service that
requires inspecting or replacing
transmission/front differential fluid
should be performed by a qualified
technician following procedures in
Lexus service and repair publications.

Seems clear to me.

nicnac

The infamous "lifetime fluid" ...................there is no such fluid made and how long is the lifetime?.................. thats the problem these days with tech authors and the like ............... they have no engineering basis but just look at the way they can hype up there material . We in the aviation industry on the other hand beieve in keeping you in the air and not waiting till the engine blows up before looking at it ............ I despair at the attitude these days ................ very few professionals left !

ukrkoz

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.