Hello,

Sorry if this has been asked before as I didn't find much info. My friend just changed his transmission oil per honda recommended service guide on his accord at 60k miles. I was wondering if our Lexus IS (mine 2016 300) should change the transmission oil? And if so at what mileage ? I don't see anything in the service manual for changing the transmission oil.

 

It was mentioned in this thread about the 60k service that it could be done at 60k miles, even if it's not recommended in the manual. I think the manual only requires the old manual IS250's transmission oil be changed around that mileage. ​​​​There's a video for a GS in there showing the state of the fluid around 60/70k miles.

 

Lexus doesn't list a service interval because it's commonly referred to as "lifetime fluid". However, changing the fluid has been shown to resolve issues with the transmission.

I would say I agree that 60k is a good time to do the service.

 

Got mine done at the dealership and they didn't really give a "full flush" option but a "drain and re-fill".. I did 2/3 parts from what I remember at 40K miles. All dealerships except 1 in NJ offered to do complete the service

I went to a 3rd party mechanic who I get my oil changed from and they said they could do it but for some reason, this job, I got done at the dealer

 

Arentz is correct in the fact that it's technically a "lifetime" fluid (however much one can be). Unless I'm mistaken the interval per Lexus is 120k miles. With that being said my local dealer refuses to touch any sealed transmissions for flush/changes unless they have an actual problem. In the TIS manuals it's also implied the transmission fluid shouldn't be changed for sealed units unless a major repair is being done to the transmission. If it makes you feel better I'm pushing 140k+ miles (over 37k so far this year) with an increased redline, plenty of aggressive driving, test N tunes, and AutoX days with no problem. Engine oil analysis also still clean from blackstone labs.

 

My previous Toyota used “lifetime” type iv fluid. It’s a darn fine lubricant but nothing is lifetime. I always did 60k drain refills but the fluid always looked pretty good.

 

My dealer (Sewell Lexus) told me the same thing. I was planning on doing it myself anyways but was curious as to what they were gonna charge. I was honestly shocked that they refused to even do it upon my request for a quote.

 

I was shocked too. We're all familiar with how long Lexus/Toyota vehicles can last so I'm honestly just gonna run the original oil till/if it dies. Planning on going back German here in the next year or two when the market settles and I highly doubt the transmission will go before, even with my mileage.

 

My transmission was overfilled by nearly over a quart when I checked for the first time last week. Not sure if out of factory or if the previous owner had it serviced.

Planning to do a flush soon as the fluid was black. Not sure if the extra 1 quart is enough to do any damage, but a flush will hopefully clean it out. The old food didn’t smell burnt or anything though.

Note if you’re going to DIY, you need a 24mm wrench with an offset in order to access the fill plug. My socket + ratchet didn’t have clearance.

 

Just curious how you checked the fluid? I have the 8 speed transmission and since it's sealed there's no dipstick to check. My understanding from awhile ago was you just open the overflow valve/screw and add fluid to the refill hole until it comes from the overflow valve and close the valve when it's just barely dripping. For stuff like this or when I replaced my axle I just rent the TIS as needed.

 

Yeah I unscrewed the overfill plug (while the tranny was cold) and to my surprise, a strong stream came out. I plugged the overfill back in and then did the tranny fluid adjustment with Techstream to set to proper level.

 

That does make me feel better thanks. I also called the dealer and they said they would not change the transmission oil due to it being sealed and it could bring problems if they change it. So I guess I'll leave it the way it is now.

 

For the record, I don't believe it's a "lifetime" fluid... I mean, I suppose the fluid might last the lifetime of the transmission if it never gets changed and is driven super gently. But I somehow doubt that, given it is being subjected to lots of heat and friction every time you drive the car.

 

this subjects been beaten to death 10,000x, “lifetime fluid” means warranty period... if ur transmission goes out if warranty do you think Lexus will say “oh sorry we should have recommended a fluid change we’ll take care of ur transmission no charge” or “that will be $8000 for a new tranny”.
If you care about optimal performance and reliability out of warranty, change the fluid...if you don’t, don’t change it.
All I know is my fluid was pitch black at only 50,000km mileage.

 

I have lifetime power train warranty. The company state on the contract keep up with maintenance, went to Lexus for a recall and I ask them about transmissions service they say you have warranty leave it alone plus the manual say no service need and it will but N/A for the contract. But ok the other hand if you don’t have warranty drain and fill on very oil change you should be good