colenzae

I was a little shocked to find out I can't service my transmission. Should I be concerned???
What have other people's experiences been with the trannys on these cars??
Bought used last year: 2010 with 71,000 miles. Now it has almost 100k. We drive this car!! It will see mostly highway miles. Love the car.

skywise

I haven't worried about it too much as it's the same system as has been in the Prius since 2004.

http://en.wikipedia.org/wiki/Hybrid_Synergy_Drive

colenzae

Wow. From this article, it looks like the transmission is completely electronic without any fluid to change. Well knock me over with a feather!!! Honey......no more transmission fluid changes!!!!

TonyHS

Actually the Prius chat folks do recomened a Transmission fluid change, as well as a Transaxle fluid change.

I'm not sure if we are allowed to crosslink, but if not I'll remove the link http://priuschat.com/threads/transmi...-change.88903/

colenzae

I was told by Lexus there is nothing to do to this transmission for its service life. It is not a prius.
Has anyone else out there been told anything different?? I believe this vehicle shares components with the Camry Hybrid, not the prius.

TonyHS

I'm not sure why the dealer would state that. True this engine and tranny are not the one in the prius. However they are very similar in many ways and maintaince is very similar. The transmission does have a fill and drain plug, and there is a procedure to change it. However I'm not sure why they state it's not servicable for the life. There are some mentions in the prius forums that the Toyota WS transmission fluid might have a service life of 200k miles, but has yet to be proven. If that is true it would be very silly not to change the fluid at some point, since it is the same fluid and the transmission has a 10mm fill plug and a 10mm drain plug.

Lexus maintaince also does regular checks of the transmission fluid.

Unless Lexus expects the car's service life to be 200k. I'm hoping mine will go far beyond that and I'm considering changing my transmission fluid soon.

I have not spent any time in the Camry Hybrid owners forums as I've never owned one, but I would expect they talk about and do transmission fluid changes also.

Prehaps your dealer has has not or does not know how to change the fluid for the HS 250h?

colenzae

Here it is verbatim from the back of the "Updated Maintenance Requirements" supplement in the owners manual: "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 dip-stick on the transmission."

I will inquire to this further but I don't see any way to check the fluid levels on this tranny. Do you know where the fill/drain plugs are?? Do you have to remove the plastic shrouds under the hood to see them??
Also, if a Lexus dealer did not know how to change the fluid for my car, I would shoot the service manager in the head on general principle.

Stoodo

iTrader: (4)

TheAirman

Wow, that's kinda' weird that they would say that.

Looks like it can be done to me.

The tranny being a CVT, it's probably a little different than the old slush box I had on my MG though. And I'm sure the fluid costs a buck or two!!

colenzae

Ok, so the transaxle fluid is able to be changed. It seems what people are referring to above is the transaxle fluid, not transmission fluid.

hmong337

This is all wrong! You guys better change the fluids or risk an $8000 repair bill.

Here is my thread.
https://www.clublexus.com/forums/hs-...fluid-now.html

Clutchless

This has been covered for the Camry Hybrid (same drivetrain) over at the Toyotanation forum
http://www.toyotanation.com/forum/10...-question.html

Also this is a great how to explanation with photos http://www.greenhybrid.com/forums/f4...-change-26791/

Magellan55

So after reading some of these forums, all I see are people assuming it needs to be changed because it looked a different color than new. I don't see any evidence of transmission failures due to lack of changing the oil. How many are applying their knowledge of old automatic trannies to this new cvt and assuming it still applies?

I understand being safe is better than sorry, but really, is anyone on these forums really smarter than the engineers that designed your car and spec'd out the maintenance schedule? If the dealer could make more money by changing another fluid, don't you think they'd jump at the chance? If Lexus would be liable for a class action lawsuit because of tranny failures due to false claims of lifetime fluids, don't you think they'd avoid it?

I don't buy any of this - it's just not in Lexus' best interest to tell you not to change a fluid unless it really is OK. Sometimes engineers design a sealed system for a reason, like not letting air or dirt enter a system. Wheel bearings come to mind - when's the last time anyone repacked a wheel bearing? Maybe the risk of contamination during an oil change is worse than the risk of running on old fluid.

Maybe I'll be the guinea pig, but i don't plan to mess with it if the service manual says to leave it alone.

TheAirman

On this post, I totally disagree. It's the age old debate that has been going on since manufacturers started "free" maintenance programs with the purchase of an automobile.

And let me ask, since "engineers design a sealed system for a reason, like not letting air or dirt enter a system", as you said, why did they add a drain and fill plug on the HS?

Back when they started with the "free maintenance" programs, and engineers were trying to design a "maintenance free" car, some of the transmissions were truly "sealed" and it was almost impossible to get the fluid out of them. They had no fill or drain plugs. And most of them failed early. But it kept AAMCO in business.

The same can be said for ball joints and U joints. Remember when both of those had actual grease fittings? And you had to take your car in for a old fashion "lube job"? Those who did kept the original joints the life of the car and beyond. Nowadays with the maintenance free ball joints, if you have over 100k on the car, you know your due for new ones.

In my 35 year career as an Engineer with the airlines, I've worked with many devices 10X more complex as the HS transmission, that required fluid in their operation, and not one of them ever were "sealed" or didn't benefit from a fluid change at least once in their operating life.

Just like changing the brake fluid, everyone has an opinion. Some do, some don't. But fluids wear and break down, so if you want longevity, I say change it.

And just think if they never changed the fluid in the french fryer at your local Mc Donalds?

LeX2K

It applies because the transmission still has rotating assemblies, meshing gears, bearings and sleeves etc. which means friction and heat. Heat breaks down the oil and it no longer protects as intended. And when that happens metal particles are suspended in the oil which accelerate the wear and eventually you have a runaway wear condition and a transmission failure.

A Toyota/Lexus hybrid CVT is an infinitely variable gear and bearing system controlled by electric motors. It is still a mechanical device, why does the need for replacing fluid change just because it also contains large electrical components? Answer is it doesn't.