Questions about my recent ATF Transmission Fluid change

The listed capacity in the shop manual is 3.5 quarts for refill after a fluid replacement.

The shop manual also states that 0-10mm below the fill plug is an acceptable fluid level.

Usually I fill the Gen II Prius transaxle until it becomes to pour out of the filler hole, then I put the plug in when it slows to a drip.

Having the car level is probably best for an accurate fluid level check, but considering that you put in slightly more than 3.5 qt, there's probably more than enough fluid in there.

Now, I would have used Genuine Toyota ATF-WS instead of Redline D6, but that's an entirely different discussion.

 

And an important one, I got no feeling on the Redline site that D6 had the electrical characteristics needed to bath the Motor/Generators. (Nor is it the ATF the site recommends for a Prius)

 

I think your procedure is OK and you probably have the correct amount of fluid. You most likely spilled 1/2 quart and have the requisite 3.5 quarts in transaxle.

I too am concerned about what you used. We (those of us on this site) have always used Toyota ATF WS because it is known to have the proper electrical characteristics. What you have in there now is a big question mark.

I remember that Bob Wilson tried a different fluid in his Gen1 or Gen2 transaxle and it did not work out well but I don't think we can find that old thread.

 

^^^
http://priuschat.com/forums/gen-ii-...-atf-test-in-nhw11-01-03-prius-transaxle.html

AFAIK, Bob never had a Gen 2 (NHW20). He's only had a NHW11 and ZVW30.

He also posted http://priuschat.com/forums/gen-iii...on/69919-zvw30-transmission-oil-analysis.html.

 

This is likely to be a very expensive mistake, as in several thousands of dollars. The Prius transaxle contains the electric motor-generators (MGs). In addition to lubricating the gearing, the transmission fluid in the Prius also cools the MGs. The transmission fluid must be compatible with the insulation of the MG windings. Only one type of Toyota ATF is approved for this use.

If it were my car, I would immediately drain the transaxle and replace the fluid with the proper stuff.

It's your car, so you can take a four-digit risk if you want. Should you decide to keep this non-standard ATF, check back from time to time and let us know how it works for you.

Tom

 

Tom, you should review edthefox's analysis of Redline. bpollard, don't panic, everything that you did in your trans service is fine, including the fluid choice.

Whether ATF WS or Redline D6, it is just synthetic ATF. As long as the fluid does not oxidize, the winding insulation is fine. There have been electrical and electronic controls bathed in transmission fluid of all types for decades. Toyota T-IV, a differently formulated ATF, is spec'd for Gen 1, and those have a higher failure rate. Is it the fluid or design, or both?

As far as I know, no one has ever added non-Toyota ATF to a transaxle and reported a failure.

 

You should put in the new fluid with the car level, and let any overfill spill back out until it quits. Also, I can't see using anything other than the spec'd. Toyota fluid.

 

D6 used to be spec'd to comply with ATF-WS, but is no longer. Did your bottles indicate compatibility?

In my opinion, you're safe if you refill with the drain-and-fill capacity of 3.5 quarts.

I'd be a little leery.

 

I tried AMSOIL ATF in the NHW11 only to find:

• 'eats yellow metal' - the first oil analysis showed excessive copper and I found another web site that reported this problem
• getting rid of 'bad' oil with clean oil DID improve, cold-weather (32F/0C) hill roll-down performance
• about a 20-25% carry forward when you change the NHW11 oil which can drop the pan

I had both AMSOIL, Type T-IV, and Type WS oil, virgin samples, tested and the Type WS has the lowest viscosity of all three. I have switched my NHW11 to Type WS and continue to do regular changes, ~30k miles, with oil testing. I remain happy with my switch.

Our ZVW30 had the first transmission oil change at 5k miles with a fairly extensive oil analysis. Microscopic examination revealed 'debris' that appears to be sealant beads and 'machining bits' in the oil. I have a second sample to send off but am thankful I got that cr*p out of the fluid early. If you plan to keep the car for a decade or longer, I'd recommend changing the transaxle oil with the first engine oil change. This will minimize the amount of manufacturing debris and hopefully reduce the wear and long-term friction effects.

Bob Wilson