Transmission Noise?

First, have you ever drained and refilled the ATF, if not do it now as it is over due.

There is also a whine that comes from the inverter that is a function of current in or out of the HV battery which can be annoying, but does NOT indicate a pending failure.

There can also be tire noise that can whine especially wen the tires are worn down.

JeffD

 

wheel bearing? velocity joint?

 

Wheel bearing going bad could cause a whine related to speed only.

At 145K the transmission fluid _needs_ to be changed. If you know it has never been changed, change it now. If in doubt if it has ever been changed, change it now.
The transmission has a drain & a fill plug. If you can get the Prius on a lift you can remove the fill plug & use your little finger to see if the fluid level is within 10mm of the opening. If there are no leaks, it should still be close to full.

 

Don't bother checking the level just get it changed out. Call around to some dealers and get prices. No idea where you live as you didn't fill out your state but prices are much higher in urban dealers.

 

The Prius transmission is like a manual transmission in that it has drain and fill plugs. There is no torque converter or fluid pump or operating clutch pack or valve assembly, and the capacity is less than 4 quarts, not 7 or 8 or 12 as with some automatics. There is nothing to be flushed. Anyone that offers to "flush" your Prius transmission is a moron or a thief or both.

 

or hoping to 'flush' your wallet.

 

Do you know the noise is coming from the front wheels? The rear wheels have bearings that fail also.
When a wheel bearing first starts going bad it may be difficult to isolate the noise to a defective bearing.
Eventually the bearing will have excessive play but at the early stages of failure this may not be evident.
With the vehicle raised, rotating the wheel & listening may reveal a noisy bearing. If you can do this in a quiet area it works _much_ better!
If you can get both the front tires off the ground at the same time you can compare the left/right. Same with the rear tires.
When the defective bearing is located, it is only necessary to replace the one side that is failing. There is no need to replace both sides on either the front or rear axles.

I found this (2-part) video on youtube on replacing a rear bearing:
youtube.com/watch?v=2mC9buJ7nvY
youtube.com/watch?v=kCL8Nyyj2jk

 

How much to change the ATF at Firestone? I'm going there tomorrow for another issue and would love to compare prices!

 

I'm not sure about what exactly happens when you put a Prius in neutral, but you can't draw this conclusion. There is no physical disconnect between the ICE, the PSD or the wheels. I think the only thing that happens when you put a Prius in neutral is that the ICE will not rev when you press the accelerator. It will not shut off the ICE nor will it decouple it from the PSD.

 

Does Firestone carry the WS transaxle fluid? If they added something inferior in there, as in regular transmission fluid, you'll have to do it all over again.

 

Are you certain they used the correct oil. The wrong oil can fry your electric motors.

 

The rear wheels have bearings that fail also.

If you think it might be rear wheel bearings - you could jack up one side (or the entire rear) of the car and try to "wiggle" each wheel to see if you get any play in them. Also spin them and check for any noise. Oh - make sure you have the parking brake OFF.

 

In your dealings with Firestone, was the term "Toyota ATF-WS" ever mentioned?

 

$75 for atf change is very good.
Did it help your noise?

 

They probably used that Kendall Versatrans stuff. I don't think Kendall approved that for use in CVTs.

 

^ Yeah, this sort of thing could be a slumbering giant. Alternate fluids may be ok, case by case, but why the hell chance it.

Then there's a certain Volt owner here, who traded in his Prius with an alternate fluid. Whoever bought that car is continuing his experiment.