Hey guys. Have been trying different methods of draining the transaxle after hearing light bearing noise from dirty fluid. 75k no tranny service. I changed the oil twice. (4 quarts twice at cold temp). The first time the transaxle fluid was changed 4.5 quarts came out. They overfilled it from the factory to make sure it survives. This is my reference point. The first two times I only used 4 quarts to clean the tranny out. The final attempt to get rid of the bearing noise, I flushed immediately after a 2 hour drive home. The transaxle was hot and this time, it completely cured the issue. Flush hot !!! Throw a little extra fluid in it and it won't hurt! Thank the lube gods.
I would suggest to fill the transaxle with the car level (and probably raised), add fluid at the fill hole till it starts coming back out. Then reinstall the fill bolt. It should take somewhere between 3.5~3.9 quarts. A funnel and 3~ foot hose extension from above is simplest. Are you using Toyota ATF WS fluid? The attachment is Repair Manual instruction for transaxle fluid change, for regular 3rd gen Prius (2010 through 2015), but I think it's 100% applicable to the Prius v, it's the same transaxle. Can you describe the noise? Is it all the time, or just under certain driving conditions? Has the noise lessened since the fluid changes?
So to be clear. I only use Toyota ws fluid. The noise was faint and was caused by dirty fluid. Sounded like it came from right where the differential is in the transaxle. After a hot flush, the noise ( which sounded like 1 second of catscratch to 0.8 of normal operation to 0.5 second of cat scratch and normal again consistently***) stopped all together. Topped with 4.5 quarts of fresh fluid. I noticed that whenever I go over a heavy bumpy road, the debree that stayed from past dirty fluid knocked itself loose and back into my clean fluid. I guess I have to do a tranny fluid change a 4th time but I might wait it out to knock all contaminates loose first. I used a hose that had a silicone lip to create an air tight seal in the fill hole to get all 4.5 quarts in. The car feels brand new after 80k miles
A dab of dried silicone or painters tape around the hose. Make sure the tape doesn't fall in your transaxle. Also make sure you're gravity feeding it from the engine bay because air will take time to escape the transaxle as fluid creeps in.. So it takes longer to get the last quart in.
You've heard a noise. You're convinced yourself that multiple refills, and intentional overfill (4.5 quarts vs Repair Manual spec which is 3.5 qts), are the remedy. You may be onto something, but I can't see why you're putting all your chips on this one square. Too, this amount of overfill may be detrimental.
At 75K miles there's so much caked debris in a G3 axle that when you go over bumps it knocks some of this debris loose. Only available on this site folks.
