E-cvt Fluid Change

[Mikeyb999]

I know Lexus claim the cvt gearbox is sealed for life, but looking around the net there are a lot of people (mostly state side) recommending a fluid change.

My CT has covered 105K now and I'm not planning on a fluid change, but has anyone else bothered?

Are there any horror stories of box's going bang?

[rayaans]

Ideally you should change the cvt fluid at around 100k miles. This isn't an official Toyota or Lexus interval but I'd say 100k is about right.

This link should help :

http://notpetroleum.com/2012/04/13/reconditioning-a-toyota-prius-changing-the-cvt-transmission-fluid/

[200h]

this is something i am never happy with when a gearbox oil is filled for life,oil will over a period of time degrade and collect metel debris ,and for these reasons should be replaced ,

so why is the lexus cvt oil different from any other.

i have had this with mercedes years ago on a manual box i told them i wanted the oil to be changed,but then they couldn't give me a price for the replacing of the oil,it took them about 1 week to get me a price i think it cost me £70 but i was happy knowing it had been changed and thats what mattered.

[rayaans]

this is something i am never happy with when a gearbox oil is filled for life,oil will over a period of time degrade and collect metel debris ,and for these reasons should be replaced ,

so why is the lexus cvt oil different from any other.

i have had this with mercedes years ago on a manual box i told them i wanted the oil to be changed,but then they couldn't give me a price for the replacing of the oil,it took them about 1 week to get me a price i think it cost me £70 but i was happy knowing it had been changed and thats what mattered.

Well its not but I think it basically means that you don't have to change the oil and it'll make a little difference but probably not enough

[adnewton]

If Lexus state its for life them why bother changing? Oils these days are designed to last longer than service intervals.

Do you top up fluids in your sealed for life batteries?

If anything happens due to oil degradation you just point to for life statement. Don't forget this also helps the environment by reducing disposal into land fill etc.

[Wass]

I am guessing that the term "for life" means for the life of the gearbox. So the fluid will stay in the gearbox until the gearbox goes wrong. One could say that about any gearbox or engine but manufacturers prefer not to because the chances of the components consistently outlasting any warranty periods are reduced.

Replacing the fluid will most likely prolong the life of the gearbox simply because new fluid does its job better than old fluid. The Lexus gearbox has gears and a chain and an electric motor/generator in it. Gears give oil a hard time in that they physically squash and break up the polymer chains contained within oil (ie the gears wear the oil out) with reduced lubrication properties caused by worn out oil, the gears will wear each other out. Wearing gears mean that tiny particles of metal are being washed around the gearbox which contains an electrical motor / generator as well as some bearings. These tiny metal particles will not be doing the electrics or the bearings any good.

All this does happen within the Lexus gearbox, however, Lexus (and Toyota) take the view that since, in the most part this doesn't lead to gearbox component failure within the first 100,000 miles, it is of no great importance to the reputation of the company or the product. Of course, if owners of the CT or prius would like to lessen the chances of gearbox failure in the interests of enhanced longevity, then they should change the fluid. My guess is that once the fluid smells burnt, this is indicative of damage to the fluid itself and therefore changing it would be beneficial to enhance the longevity of the system. However, most people would point towards the fact that very very few of these gearboxes fail in the low ambient conditions of this country and so the effort of changing the fluid would be somewhat wasted.

Given the reputation of these gearboxes, maybe the realistic lifetime of the best of them is in the region of half a million miles by which time the wheel bearings, engine, suspension and everything else will also be shot. Who knows? What might be the point of having an immaculately kept gearbox surrounded by a barely serviceable car? Could it be like Triggers broom? "this car has had 4 different engines, 10 different drive shafts, 20 sets of brakes, 34 sets of tyres, 3 sets of suspension and two body shells but it still has the same nut behind the wheel and the same gearbox"

[ColinBarber]

It is a balancing act. On one hand Toyota are under pressure to reduce the environmental impact of vehicles and reduce servicing costs and on the other maintain their brand reputation for reliability. You could also argue that by having it sealed results in less failures because people aren't replacing the factory fill with incorrect fluids or under/over filling.

Personally if I was intending to keep a CT long term then I'd replace the fluid every 5 years/80,000 miles. Luckily for CT owners, the same transmission is used in the Prius and the first ones are two years older than the first CTs - if there are problems with transmission failures those failures should start appearing on them before it is too late.