HELP Prius "rocks" while in Park??

Ah, you are so right. If the wheels were to spin, and the motors free wheel, the planets on the PSD would spin and the planet carrier to the engine remain stationary, correct? So if the pawl were to be sheared the car would be in neutral, and ICE and MG1 & MG2 freewheeling & safe, so long as it isn't going faster than the motors can spin (42MPH?) That would make a failure of the pawl a lot less damaging to the vehicle, assuming it doesn't crash from being in neutral (sound right?)

Thanks for explaining that, fits with why the car rolls more than an auto trans.

 

Ummm, well... you've trashed the PSD, so I'm not sure that counts as "less damaging".

Unless you think it's safe to drive around with a sheared off parking pawl grinding around in the guts of the thing.

I wouldn't worry about it, though, parking pawl failures are pretty uncommon unless something else quite extreme has happened.

 

Yah that would be bad. At least your engine and motors would be okay! lol

I set the brake maybe 15% of the time when I remember, and no worried about the other 85% when I forget. I just hate the rock, especially when the car is on (doggie enjoying AC) and the ICE kics in, always make me jump.

 

I always use the parking brake. It's a lot cheaper to replace a bumper pad than rebuild a PSD...

 

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Fair enough, and I'm certainly not saying it's a bad idea, but did you remember to multiply the 2 costs by the relative probabilities?

If it costs $500 to repair a bumper, and that has a 1% chance of happening over the life of the car, but replacing the PSD costs $5000 and has a 0.0001% of happening over the life of the car, then you've got a false economy there. By a factor of 1000.

BTW, I would estimate that those example numbers are pretty close to accurate, except for the fact that damage severe enough to actually break your parking pawl will almost certainly total the car as well.

It's a different matter on a hill, where simple failure of the pawl to engage in the first place might result in serious damage to life and property. Applying the parking brake is always necessary in that situation, but not because of whether it will damage your bumper or PSD.

 

the fact that damage severe enough to actually break your parking pawl will almost certainly total the car as well.

Parking pawls are often not very rugged, and there is a tremendous leverage advantage being applied against it if the car is pushed. I don't know specifically how rugged the Prius pawl is, but I always use the brake as insurance against breakage.

The probabilities aren't quite that way-- if you are rear-ended while parked, you'll replace BOTH the bumper and the pawl.

 

Since no one in the forum has mentioned shearing their pawl, I'd guess they're at least as rugged as the average auto trans.

 

Prior to the forum crash, there were several posts about broken pawls in other cars. I guess because I park either on a sloped driveway or on sloped streets often, it would never occur to me to NOT use the parking brake. I've heard that metallic, almost bell-like CLANG when people release their jammed parking pawl, and it just doesn't sound remotely healthy for the tranny!