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Originally Posted by orange4boy
Another possibility I also remember is that left front axle, on the dailypic's 04 transaxle thread, was full of transmission fluid and mine had a left front axle replaced too but this may not be related to the trans failure. Could just be a seal problem that ruins the CV, not the other way around. Just interesting.
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That is an area I've had suspicions although the boot at the transmission is supposed to be packed with grease. If you happen to get into the shaft areas, I would be interested in seeing high magnification of the surfaces at the seals. It may also make sense to check the seal seat.
Quote:
Originally Posted by orange4boy
What kind of temperatures are you seeing? There could be much higher spot temperatures in the windings although you would think that the oil would carry away the heat better than air. Any other oil bath electric motors that you know of? There could be some solvent/corrosion effects from the oil if there are combustion by-products present. What happens to conductive/magnetic iron particles in that situation? Quite a soup, really.
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Welcome to my world! Here is my
transaxle temperature study. I recommend seeking out the ORNL reports on the Prius. One of the reports on heat flow indicates 2/3d is via the aluminum case. So what we find is MG1 warms up and soon reaches parity with the ICE temperature. MG2 takes longer but its temperature seems to be fairly moderate until speeds begin to increase over 65 mph. Then we start to see MG1 and MG2 temperatures increase and the oil temperatures go up.
Quote:
Originally Posted by orange4boy
Interesting problem and tough to diagnose. Would love to be a Japanese speaking fly on the wall at Toyota engineering meetings.
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I'm so pissed at GM management for walking away from interesting problems like this 10 years ago.
Quote:
Originally Posted by orange4boy
It could also be that this is just a normal failure rate for electric motors/transmissions. Are there any numbers on it? It can't be that bad due to the ravingly good customer satisfaction levels on these cars, just that when one does go it's sometimes $$$
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So far, it looks as if the NHW20, more than 10 times the population of NHW11s, has had only one well known failure and the symptoms were consistent with a gear failure. I suspect a manufacturing change improved the NHW20 transmission resistance to the few failures we've seen with the NHW11.
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Originally Posted by orange4boy
I suppose, like anything else mechanical taking good care of it is the best insurance. Mine has no record of a fluid change in 100,000 miles. I guess the mechanic didn't bother reading the maint. intervals.
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When you look at the transaxle oil, be sure to have a clean, dry bottle to capture a sample. You don't have to send it for analysis but if you don't capture it that possibility is lost.
GOOD LUCK!
Bob Wilson