the "jolt"

[Vernon]

I get the "lunge" in park too. It seems potentially dangerous. What if you're close to a wall, and someone steps in front of your car? Smashed kneecaps?

[Frank Hudon]

if your at a stop light/sign and you get a small "jolt" it's most likley that you have your foot resting ever so slightly on the gas pedal. The next time that it happens deliberatly take you foot and move it away from the gas pedal and you'll most likley feel a small jolt as the inverter stops powering MG2. This happens to me as I'm a two foot driver. Left brake right gas. Hold over from forklifts where we use the brake pedal as an inching control. Dumps the tranny clutch pressure so you can raise the mast or use the side shift and rev the ICE to get increased hydraulic pump pressure. Actually most forklift manufactures wish you had 3 maybe 4 legs and at least 5 arms to run all the controls that they'd like to install.

[kidtwist]

I experienced this for the first time today. It happened at a stoplight a minute or two after starting the car to go to lunch. Usually when the engine shuts down at a stop I get at most a very mild shudder. This time I got two very quick, sharp jolts. Rather frightening. I feared that something had broken and the engine wouldn't come back on, but everything worked as normal after that.

[Harper]

Originally posted by fred
lol bookrats!

<div class='quotetop'>QUOTE(FloridaShark\";p=\"82239)</div>

I've had the shudder many times when I first got the car but that always happened at the first stop sign of the morning. It has been happening less as the car gets broken in. Now for the jolt. I will sometimes get the jolt where the car lunges slightly forward and I'm in park. I'm usually just sitting there looking for something ect. and out of the blue it lunges forward. Anyone else experience this?
[/b]

Florida Shark. I experience this jolt while I am in "park" also. Anyone care to elaborate?

[greencanuck]

I experienced this for the first time as well. In PARK, and 'READY', just having a bite of a sandwich before I got going, and...jerk. Just wondering if this is the ice starting up (which it definitely was) and applying torgue to the parking pawl. If this is the case, it seems like a lot of stress being placed on that pin. Would this be more stress than a regular automatic transmission places on it's components?

Perry

[Frank Hudon]

your correct in the thinking that it's torque applied to the park prawl. The prawl engages a lug on the intermediate reduction gear in the Prius. To say that it's applying excessive torque to the prawl, no, in a regular auto tranny the torque is multiplied and then applied to the prawl, but it's constant so you don't notice it.

[u4iia]

I have about 300 miles on my Prius. When I turn it on for the first time in the morning I get a little lunge in reverse when the ICE starts. It will hit the pawl then go forward. This is not a dramatic event but startling for new Prius owners like my self.

[woemcats]

I've never had the jolt of the car moving for ward or back (I assume that's what some of you are describing). But when I pull out of work in the evenings, I nearly always stop at a stoplight right away, and usually the car idles nearly all the way through the light, then the engine shuts out kind of rough and the car shakes, but it doesn't move since my foot is obviously on the brake.

What was odd today is I turned the car on and put it in D and took my foot off the brake and it rolled backwards at idling speed, as if it were in R. It then shifted to N and wouldn't shift out so I had to put it in P and power down, which didn't work normally either (I had to hold down the button for a few seconds with my foot off the brake). Weird.

[u4iia]

Sounds like a MS windows machine I have. :P

[DanMan32]

<div class='quotetop'>QUOTE(greencanuck\";p=\"87947)</div>

I experienced this for the first time as well. In PARK, and 'READY', just having a bite of a sandwich before I got going, and...jerk. Just wondering if this is the ice starting up (which it definitely was) and applying torgue to the parking pawl. If this is the case, it seems like a lot of stress being placed on that pin. Would this be more stress than a regular automatic transmission places on it's components?

Perry
[/b]

Hmm, that makes a lot of sense, considering the 'transmission' is always engaged, unlike other trannies. Being that there is usually some backlash, if the ICE starts, it puts some torque on both sides of the PSD, one being the gears going to the wheels. The parking pawl would prevent full rotation, but the backlash could give the 'jerk' sensation.

A normal tranny would not only have a parking pawl lock, but also would be in neutral, so no movement there.