gripau1

Can anyone direct me to a DIY on how to change the transmission fluid on the GS450h? I know it uses the Toyota WS fluid which is readily available. I've done fluid changes on the 8 speed on a Lexus RC350 and the 6 speed 3rd gen GS430 auto transmission but the I haven't done a transmission fluid change on the GS450h.

All I can find is that the diff uses a 75w-90 GL5 spec gear oil.

Thanks.

bclexus

@gripau1 - Are you really thinking about going against Lexus' firm recommendation to never change the automatic transmission fluid in your GS 450h's eCVT?

Lexus GS 450h eCVT Transmission

gripau1

My previous ride is a Infiniti Q50s hybrid, owned it for 9 years with no dramas. Sold it due to the fact Infiniti is no longer in Australia and no factory support. Use the Q50 for towing couple of motorcycles etc.
Infiniti say the same thing, trans is filled for life etc.

Since I use it for towing and spirited driving, on the Q50 there is a drain plug and check level plug and you refill via the check level plug at 30-40degC which is easy as pie. It add an extra 40-60mins to do a drain and fill on the Q50 when doing an oil change.

On the Q50 there is no torque converter just an electric motor and dry clutch to disengage the motor from the transmission, so you can run on full electric up to 140km/h.

So the answer, yes I would like to service the transmission as I'm planning to tow with the GS450h and keep it for awhile and do preventative maintenance.

gripau1

The good news is that I found the documentation for the GS450h.

bclexus

Very good. Let us know how it goes.

I'll be following Lexus' recommendation for U.S. and North America owners which is not to change the GS 450h eCVT transmission fluid because it does not need or require servicing for the life of the vehicle, which is when the vehicle is no longer deemed economical (cost-effective or worthwhile) to keep. That condition typically does not happen until the vehicle has been driven ¼ million miles or more.

Some large cities use Toyota Camry Hybrids with the eCVT transmission in their taxicab fleets that follow the recommended 'lifetime' no-service schedule even with severe driving conditions and typically those taxicab vehicles are not retired until they reach about the 300,000-mile mark.

gripau1

I had my Jag XKR for over 11 years now which I traded with the Lexus SC430. Jaguar says its life time fill. However if you go to ZF they states trans fluid and filter should be changed at 8-10 years or 100k km. Change it sooner if you drive highspeed etc. Its the same argument on the Jaguar forum, about do or don't. Ultimately its the owners choice. Yes I know ZF and Aisin are different technology hybrid vs non-hybrid, torque converter vs eCVT and manufacturers etc etc.

100% understand that Toyota Camry taxis run high km without issues. I always recommend family members to get a Toyota hybrids vs any other brand or EV if they want to keep it for a longtime without issues and easy on the pocket and not very mechanically minded etc.

We don't have unlimited speed limits autobahn like in Germany, our speed limit is only 110km/h. So technically its easy on the transmission.

The day I change the fluid and filter on a low km Jag (40k km) the shifts becomes silky smooth and I know in the back of my mind that the fluid has been changed and can handle the driving that I give it. It was the same thing with the Lexus SC430, trans fluid change and shifts were nice and smooth.

JGB93

Thanks for this post brother! Keep us updated on the procedure, take pics if you can.
I've been looking for this, I respectfully drive mine quiet hard, but it's thoroughly taken care of.

@bclexus generally speaking the "life of a vehicle" from factory means 8-10years under normal driving conditions in city and up to 60mph/100km. Edging up to about ~150,000miles.

Yes, there are many examples of high mileage hybrids and heavy duty driving from taxi companies with hybrid camrys on original trans fluid. Yes they may? be fine. Testament to Toyota reliability.

But there are always exceptions that exceed the "life of a vehicle" under factory definition.
and as long as the procedure is done correctly, there is no harm and only upside to maintaining all fluids adequately.

bclexus

Probably not, but I see no advantage in replacing any fluids long before it is recommended or even remotely necessary. I can't imagine it's worthwhile in any way to replace any fluid, including a lubricant, at a point representing less than 50% of its authoritative, dependable and expected life. I find no benefit in replacing engine oil and oil filter at less than 50% of the recommended mileage. I certainly will not be doing that with the eCVT transmission fluid either.

Chances are almost 100% certain I will not own the vehicle when the time comes - if it ever does - when there is truly any real benefit in replacing the eCVT fluid. I strongly suspect this is true for almost everyone. But if someone really has the desire to do it anyway; whatever will be, will be...

gripau1

For anyone who wants to do the transmission service, do at your own risk I take ZERO / NO responsibility or take it to Lexus etc.
If you are mechanically minded, its easy. There is no magical fairy dust that you need to use.

I wanted to do this because I'm planning to do a road trip over the Xmas break which has alot of extended spirited driving and towing. So I want my vehicle to be in tip top condition for the trip.

This is how I did it, it takes a couple of hours to do. Most of the time is waiting for the transmission to cool down and drinking coffee.

The cross member needs to be loosen (4 bolts) so that the transmission cover can be removed.
The 4th Gen GS450h has a transmission cooler, the 3rd Gen GS450h does not have it.
Same with all newer generation Toyota and Lexus hybrid and non hybrid system the transmission RWD /AWD setup has a drain plug and an overflow plug in the pan.
Drain the transmission fluid and measure what came out. Just to double check I measure and weigh the fluid that was drained out.
Refill the transmission via either transmission cooler hose as outline by Lexus or what I did via the overflow port using a 8mm diameter hose that fitted snuggly in the overflow hole.
I weigh and measure the new fluid adding just a little extra to do the 30-40degC level check via the overflow port.
Circulate the new fluid by rowing through the gears / or going drive it around the block.
I drain and fill three time as outline in the workshop manual.
Toyota Techstream software was used to check the transmission temperature.

Below are the results of 46k km OC. The oil has started to oxidise and colour has started to change from red to brownish and viscosity has reduced compared to new fluid. No burnt smell etc.
About 3.5 litres of transmission fluid came out on each drain.
Ambient temperature was 25DegC.

The seat of the pants results.
The very slight backlash at 50-60km/h when I'm lightly touching / feathering the throttle on and off is gone.
The noticeable resistance feeling when changing gears from reverse to neutral to drive is completely gone. It now feels like that the gear selector is not connected to anything - no resistance or noise.
I've driven in about 1400km 70% in bumper to bumper traffic and several 35-42DegC (108F) summer very hot days for a total of 6.5hrs no issues what so ever.
I Also notice the EV light tend to switch on more often after the fluid change.
A slight reduction of fuel usage, reduce from 7.7litres/100km (30mpg) to 7.0litres/100km (34mpg) roughly the same day / route / ambient temperature bumper to bumper to the office and back.

Overall I'm happy with the results and feel more confident that the transmission will not let me down when I'm enthusiastic with the throttle.

JGB93

buddy, i agree with you. Im just pointing out there are many examples that exceed a factories definition of "lifetime" which you seem to have to have over looked.
Is it still fine after 10 years, 120,000miles? Yeah probably. Will it continue to be okay for more to come? Sure. Does aggressive acceleration and driving over 120mph reduce its service life?Absolutely.
But that's all beyond the scope of a factories intended service life. I'd argue its beneficial, if done correctly and you are probably beyond "50%" of the fluids life. Not that you would want to come close to the end of a fluids life before changing, especially under extreme circumstances.

Thank you @gripau1 that's incredibly helpful. Iv serviced a few transmissions and I know exactly what you're taking about in regards to those subtle improvements, you don't notice until they're corrected.