Should I change trans fluid......

Change it now.

 

You will be fine. Just get yourself some WS and its like a differential. You drain out and then you refill until it trickles out. Easy. Make sure you are on level ground and it takes approximately 4 quarts.

 

That recommendation to not change it is in regards to automatic transmission. They dont know anything about a prius. Thankfully a prius doesn't have a transmission. So go ahead and change that fluid! It's a cheap and easy job.

The prius uses two electric motors and a plantary gear set instead of a actual transmission .

 

Change it, the car will be happier.

 

More specifically: make sure the car is level. Maybe a fine point.

Use Toyota ATF WS, nothing else.

 

No lubricant lasts FOREVER! You are beyond overdue.

If engine oil changes were NOT listed in the maintenance schedule, would you forgoe engine oil changes?

Read Post #473
ATF fluid changes ARE Required. | Page 24 | PriusChat

Upgrade to a hefy magnetic drain plug.
Read the transaxle oil analysis by Prof Eddenberg and Bob Wilson; link contained in Post #473.​

Frodoz737 stated it best: Manufactures maintenance schedule are a bare bones minimum, to give the appearance of low cost of ownership.

Brake fluid also needs to be replaced periodically. This too is not listed for the Gen 2.

 

Toyota Canada maintenance schedule (for all vehicles) includes brake fluid change tri-yearly or 30K miles, as of 2012 IIRC.

 

Most (all?) conventional automatic transmissions have a series of tiny twisty passages called Hydraulic logic that control shift points. the worry is that these will get blocked, limiting the ability of the transmission to shift.
As the Prius eCVT transmission never shifts at all, it has no hydraulic logic to get clogged.

Here is a picture of the twisty passages your car does not have:

Nothing like this exists in a Prius, the logic is all electronic.

 

Even with a conventional automatic transmission, I can't see the harm in a fluid change, regardless of when, if it's done right, and proper fluid used.

 

Important tip: Open/break loose the fill bolt first. You don't want to drain via the lower bolt first and then find out the upper fill hole bolt is seized/rusted/etc.

Overall, I find the job easier than an oil change. Just need a short length of tubing so you can fill/pour from above the engine.

 

I figure it's a wash. If you open the drain bolt first, and then find you're having trouble with the fill bolt, you will eventually be sucessful: you will be MOTIVATED.

 

That fill bolt is really socked on there. It will require a breaker bar.