Transmission fluid change

[JCT-DK]

Hi.

If this topic already been discussed please excuse me and maybe provide a link to the thread. 

My car had done almost 70000 miles.  Would it be adviseable to change the fluid or not? I am sure my dealer will tell me no but what could worst case happen if I dont.

What would wear out the fluid?

Thanks.

Kind regards JCT

[JCT-DK]

Oh i forgot to tell its a Yaris hybrid mk3.

[TonyHSD]

Heat . 
The transmission fluid has two main functions to lubricate the gears and bearings and to cool down them and the electric motors too. Best to replace every 50-60k miles . 

[JCT-DK]

Thanks Tony.

[TonyHSD]

11 minutes ago, JCT-DK said:

Thanks Tony.

You are welcome. 

[flash22]

the Hybrid uses Toyota AFT-WS (3.3L iirc) - no filter, it's the same procedure as a manual box, crack the fill plug loose undo the drain, do the plug drain plug up and fill it up till it spills out

[JCT-DK]

Hi.

Shortly I am going to have my car serviced at the Toyota dealer from where i bought it.

I asked about a fluid chance in the transmission but the dealer said no need for changing it. Its a lifetime durable fill from the factory. 

Should i have it changed despite this statement?

 

 

[MikeSh]

54 minutes ago, JCT-DK said:

I asked about a fluid chance in the transmission but the dealer said no need for changing it. Its a lifetime durable fill from the factory.

I've seen one reference to the lifetime of the box possibly being 100k as that's is the (or maybe 'a') warranty length. Quite a few people say 60-90k miles.

If you don't expect to keep it for more than another couple of years it's probably not worth changing the oil, but if you plan to keep the car much longer then doing it now would probably be good for peace of mind if nothing else.

[flash22]

technically, yes it's only an inspection item "I: Inspect and correct or replace as necessary", replaced in severe conditions - it is more preventive maintenance than anything else, fluids and oil do degrade with use and age

 

[TonyHSD]

There are probably more cars of these on the roads that has never had any transmission fluid changed  at all and they still drive fine. 
I personally mysteriously was interested to see how it looks the oil inside and I did replace my fluid at around 80k miles or 100k miles, don’t remember now.  The fluid was darker than new but nothing really so bad or to show warnings. 
Ever since I do replace this every 60k miles and the fluid seems cleaner than the very first time. 
Your car has no coolant to cool down your electric motors inside and all that been done by the transmission fluid, therefore a change every 50-60k miles seems to me reasonable and can be beneficial, for longer trouble free life. 

[JCT-DK]

Thanks for all opinions.

I asked my dealer to have the oil  checked at the service and he agreed to this. 

So I will take it from there and if the oil looks degraded i will have it changed. 

I will keep you posted.