When to change transmission fluids, etc

Is it recommended to only use Toyota's oil for the transmission, or is there a better synthetic appropriate?

PA P

 

The WS stuff is actually very good. There is no advantage to using another brand synthetic, and some of us feel you could risk damage. One of our forum members tried using a different brand in a earlier Prius, and had elevated wear metals when he tested the oil

 

Minor update-The 2001-2003 Prius does have a pan, so don't smack them if this is what you drove up in (until they commit some other blunder).

 

True, but there is no transaxle fluid filter. It would be a good idea to drop the pan so that the muck can be cleaned off the magnet and the pan bottom.

 

Ahhhhhhh there's no fun in that ....

 

Are you sure? There was a removable flat metal fluid suction with a single piece of filter media at the bottom of my 2001 transaxle. This embedded filter sheet was permanently in this sheet metal assembly. I cleaned off the media, but it was mostly clean to begin with. However, the magnet had about 3 mm of very fine particles around it. At first it looked like a metal beetle in my pan.

 

Well, I recall that the suction tube has a wire screen covering it, not a filter. In any event there is no requirement to replace whatever covers the bottom of the suction tube.

Yes, I agree that the magnet, after 50K-60K miles have been logged, looks like a fat garden slug. It is amazing how much ferrous debris accumulates and how flat and thin the magnet is once it is cleaned off.

If you just see an accumulation of fine grey ferrous particles, that is good. If you are like Bob Wilson and see plastic particles in the drain pan, that is bad.

 

Fortunately, the particles were extremely fine, with nothing else. At 90k miles, the fluid looked decent. However, I have no idea what the fluid looked like at the 60k change. I got back the Lab report on the replaced fluid. Silicon was 78 ppm, Cu was at 41 ppm and Al was at 10 ppm.