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Questions about CVT transmission

Discussion in 'Gen 3 Prius Main Forum' started by adamace1, Jul 6, 2009.

  1. adamace1

    adamace1 Senior Member

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    1. I was looking at other posting on the gen I and GeII and see some of them are looking at up to 8,000 to replace their transmission. Is this the same for the 2010's?

    2. I looked through the owners manual there is nothing mentioned about changing the fluid or any mant on the transmission? Is this true there is nothing to do to the trans for the life of the car?
     
  2. V8Cobrakid

    V8Cobrakid Green Handyman

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    no... the cvt needs a fluid change. it supposed to be done every 150k or something stupid like that. my 04 has stock fluid... just for the purpose of seeing if it last that long. others changed it early because there was a lot of new car wear and tear in the fluid.. so.. recommendations from owners on here say to change it before 60k.. heck.. 20k if you wish.

    the transmissions SHOULD last the life of the car, as long as there is decent fluid in the cvt.

    for all i know, my transaxle fluid (cvt) probably low.. and needs more fluid.. but like i said. i'm the test dummy for these cars. if it's going to fail.. i'll make it fail. ( i'm good at that )

    but yeah.... it cost to replace it... but you shouldn't have to do that before replacing your battery unless you have a very faulty transaxle.
     
  3. greylar

    greylar New Member

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    I wouldn't be worried about it. If it was a Dodge Caravan you might worry. They replace the transmissions about the same time as the brakes. But I think these CVTs are pretty durable and the traction control operates in such a way to protect the transmission so you are more likely to need a headlight lens (very expensive) from a rock. BTW if you are worried about that get the xpel headlight protectors.

    G
     
  4. adamace1

    adamace1 Senior Member

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    is there a dip stick to check the fluid level? i haven't seen it. Also i was looking at pics of the cvt and it looks like th 2010 doesn't use a chain on it any more. and it looks like they never used a belt. Are those last two statements correct? i'm going to go search and see if i can find ic on where to check it at.
     
  5. justlurkin

    justlurkin Señor Member

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    That's right, the Prius PSD transmission never had any belts.

    The Power Split Device transmission in the Prius uses a planetary gearset. It is totally different from a belt-and-pulley CVT transmission.

    The current Honda hybrids (Civic Hybrid and Insight) use the belt-and-pulley CVT.
     
  6. adamace1

    adamace1 Senior Member

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    so does it just spin? i read that it doesn't change ratios. Is that true? So from what i gather it looks like the genIII one should be really reliable and if i change the fluid three times over 150,000 miles there should be no problems.
     
  7. V8Cobrakid

    V8Cobrakid Green Handyman

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    right...

    no belts.... the Gen II used a chain. the Gen III uses direct gear ratios.

    one gear set from 20mph in reverse to 108mph in drive.

    no dipstick for the transaxle. only a fill hole. i assume the Gen III has the same fill hole. you open it.. stick your finger in.. and you'll feel fluid.
     
  8. HTMLSpinnr

    HTMLSpinnr Super Moderator
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    Based on Gen II, we'd suggest 60k miles. The fluid will run you about $25 or so for the gallon, and then another $1-$2 for the replacement crush washers for the drain and fill plugs.
     
  9. Tech_Guy

    Tech_Guy Class Clown

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    The Toyota Hybrid drive system is truly a thing of engineering beauty. Mechanically it is simpler than than any other drive system in any automobile. Consequently, there are far fewer parts to wear out. And as mentioned previously, in the 2010 version (third generation), Toyota eliminated the drive chain and replaced it with a pair of meshing gears. For more information, see the links below:

    TOYOTA: Company > Technology > What is a Hybrid System?

    Whats Going On As I Drive?

    Keith
     
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  10. JRitt

    JRitt Bio-Medical Equip. Tech

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    I was looking for an article on how the CVT in the Prius III works.
     
  11. donee

    donee New Member

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    Hi JRitt,

    The Prius drive train works the same on all generations, basically. There are differences with the 2010, in that the motor is not directly attached to the PSD (planetary gear set that connectes to the engine and generator as well as the motor). MG1, or Motor Generator 1 is used primarily as a generator, and runs at high speeds. MG2 or Motor Generator 2 is used primarily as a low speed motor with lots of torque. In the 2010 Prius, there is a second planetary gear set used as speed reduction between MG2 and the PSD. This allows for MG2 to be lighter weight and smaller in diameter. But, its a more powerful motor than in the 2nd Generation. The motors in the first generation were about as powerful, but they were not as hevily hybridized (motor terminology not car terminology). So they had more low end torque, but lost torque quicker with speed. The MG2 motors were more hybrid (magnetic field from induction and permanent magnets) , and so they have very good mid range (about 35 mph) torque.

    There are other durability and regeneration improvements in the Gen 2 transmission/hybrid system that carry over into the Gen 3. The Gen 2 has a voltage doubling inverter for MG2. This may seem like a wasteful aditional conversion loss, but it allows the MG2 to generate twice the battery voltage during regeneration at high speeds, and enough to keep pumping electrons into the battery during braking down to 10 mph, versus something like 30 for the first generation Prius. The way the circuitry works as both a doubler, and in reverse to match the regeneration from MG2 into the battery is on of the key HSD technologies. Additionally, the bearings in the PSD planetary gear seat were changed from sleeve bushings to needle bearings.

    As has been mentioned, the Gen III transmission uses purely a gear based connection to the axle differential. The Gen II used a chain and an extra set of gears compared to the Gen III. The Gen III transmission should have less losses when running down the highway consequently, and should run cooler. There are pictures on PC of the two gearing setups.

    To get the basics, Graham's Toyota Prius . Graham's website is about the best description of the system, short of engineering papers. And its geared for people with the average level of mechanical knowledge, and fills in some of the motor concepts too. You can drill down into areas where your lacking, and skip over any stuff that is simple to you.
     
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  12. defrankond

    defrankond Member

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    it was my understanding that all prius's used a sun gear for their cvt transmissions and not chain drive. also the gen II uses just over 3.5 quarts of transmission fluid not one gallon, and there are no crush washers for the fill plug or drain plug. in any event toyota says to change the fluid in a gen II every 100k miles however every 30k is more reasonable being as it is such a small amount of fluid. 4qts of WS fluid from toyota is 19.00 here and takes all of about 15 minutes to drain and fill.
     
  13. OzPrius

    OzPrius Junior Member

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    What fluid type does the Prius e-cvt use? WS? I just hit 60k miles so I need a change
     
  14. OzPrius

    OzPrius Junior Member

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    And what is the part number for the crush wafers? Thanks. Toyota dealers in Australia don't listen to its customers
     
    #14 OzPrius, Jul 25, 2014
    Last edited: Jul 25, 2014
  15. GrumpyCabbie

    GrumpyCabbie Senior Member

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    Toyota dealers in the UK and Australia (it appears) still to the Prius not ever needing the transmission fluid changed. But they're in the business of selling new cars.

    I have tried and tried to investigate changing mine but the dealers pretty much refused (in a very nice and apologetic way) and I can't find info on the correct oil being available in the UK either.
     
  16. SageBrush

    SageBrush Senior Member

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    yes
     
  17. JimboPalmer

    JimboPalmer Tsar of all the Rushers

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    Here is a good tutorial


    I recommend 30 thousand miles, then 90 thousand, and then every 90 thousand miles.
     
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  18. GrumpyCabbie

    GrumpyCabbie Senior Member

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    A technically incorrect but easy to understand way for the non engineers amongst us is that the Prius hybrid system works like a differential with one wheel being the engine and the other wheel the motors.
     
  19. SageBrush

    SageBrush Senior Member

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    hmmm

    How about a 3 input differential: the axle is the engine, and each wheel a motor.
     
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  20. David Beale

    David Beale Senior Member

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    There is a final ratio conversion -after- the e-CVT. On the GII it was done with a lifetime chain, and on the GIII with a simple gearset. The HSD is NOT a CVT. There are no chains and tapered cones. It uses magnetics to vary the slip ratio, hence it is called an e-CVT (electronic continuously variable transmission). As stated above, the mechanical part is much simpler and more reliable. The electronic controls, not so much. But as electronics are much more reliable than mechanical stuff, the HSD is very reliable.

    There is NO "shifting of gears", "operation of clutches", etc. There IS a "clutch" (looks like one, feels like one when you take the thing apart, as seen in the video posted above), but no way to release it. It's there to limit the high torque pulses if necessary, that would otherwise damage gears and shafts. It slips on "overtorque" conditions, if they ever happen.