Is it too late to change trans-axle fluid hitting 300,000 miles?

There's no way for a fluid change to cause the transmission to fail. It's simply gears and motors bathed in oil, there are no small shift passages, torque converter, etc. to fail when you change the fluid. It's never too late.

 

Never too late. Just a simple dump and fill, like the engine oil. Loosen the fill bolt first before draining the old fluid, and you'll need 3.9 qts of ATF WS (or equivalent). Be sure to post up some nasty pictures of the filthy old ATF fluid, as some members like that.

How many years?

This happens quite often.

No need to worry, your existing engine will likely fail sooner than this transmission.

Sounds like a plan, and it should be easier to replace the engine transmission assembly as a single unit.

MG1 and MG2 are part of the transmission, or were you thinking of the Inverter?

 

There are reasons (or excuses) not to change the ATF in 'normal' automatices: Bands, Clutches and valve body hydraulic logic. The Prius has none of that, so they can't go bad. You just do a drain and fill with ATF WS as there is also no torque converter.

If you listen from 4:50 He explains why you might not want to change the fluid. Your Prius has none of those parts.

 

Make sure you open the fill hole on the side first. That bolt is really really tight.
Biggest breaker bar you can find.

Takes exactly 4 quarts WS.

PS: Dont bother posting a picture of the fluid it will be black. We have seen many of those.

Good luck.

 

Asked and Answered.

Concur with all.....
As stated the Prius does not have a "transmission" so you may disregard any and all advice that suggests that changing the fluid after 300k would be a bad idea.

You have a G2.
They are what we in the phone biz call...."manufacturer discontinued."
This means that the newest transaxle (power split device) you can buy will already be over 12 years old, so I would treat it like everything else on the car and just wait for it to start giving you problems before buying a replacement.

The transaxle has stator windings inside (wires with a thin insulator coating) that can go bad if you use anything other than an approved transmission [sic] fluid. Most of them are "probably" OK to use....but I'd stick with the house blend for this job (Toyota ATF WS) instead of trying be cute and buying something in the snake-oil section of your local parts house.

Good Luck!

 

'Transmission' being the thing that transm ... er ... gets the power from the engine producing it to the axles needing it, there's really no reason to play "[sic]" games when talking about it.

So it's a transmission that's not built the same way as the transmission in an Edsel. That's totally allowed.

 

I think this is one of the few times that it wasn't the dealer who lied. They were just repeating the official word from above.