Placing (shifting) into Reverse

Don't you need to put your foot on the brake before you power on the car? Anyways, it sounds like you're not using the emergency (left foot) brake - as in it was never engaged. My routine:

Step on brake hard
Hit Power
Release E brake
Shift to R

 

probably depends on whether the engine is running or not. it comes on more in reverse than forward.

 

First, whether the engine is running or not, the car will not notice in "R" as -all- motive power comes from MG2. The engine just spins.
Second, do note that the Prius will jerk a bit when it's cold (before you warm up the transmission oil). This may be what you are seeing.

 

When the engine is running it produces forward torque on the drive train. This is opposed and overpowered by MG2 in reverse, so the car will back up, but MG2 is working against the ICE in this configuration. In this respect it does make a difference whether the ICE is running or not.

ICE startup produces a jump in torque which can sometimes produce a jerk. This is true going forward or backward, but is most noticeable at slow speeds.

Tom

 

ICE = Internal Combustion Engine (ie, the gas engine). Sorry, I have no clue about your second question.

 

Sometimes you hear a snap as the electrical relays close. It's an arcing sound, like something from an old Frankenstein movie. As for why you hear it only in reverse, that is probably a function of the specific relay.

You can also get a different sort of snap sound when the car starts to roll if the brake pads have stuck to the rotors.

Tom

 

The snap might be the solenoid actuated parking caul or pin releasing. It's located between the ICE and the HSD. Part of the coil spring torque load damper clutch assembly that connects the two.

 

Just a note here, you will never feel a jerk from cold transmission oil ... the Prius doesn't have a transmission ... or a clutch ... or a torque converter. Both electric motors and the ICE are connected full time to a single planetary gearset which, in turn is connected through a single reduction gear to the differential.

The so-called "cvt transmission" is merely the computer controlling the speed of the ICE and the speed and direction of the 2 electric motors. For a graphic of how the planetary works, go here Toyota Prius - Power Split Device

 

Is it possible that the OP is parked on a incline. The sound that he's hearing is normal, parking paw disengaging from locking ring. ???

 

Correction. There are no gears shifting, but the Prius DOES have a "transmission". Power is transmitted to the wheels via the transmission and there -are- gears in there, planetary and others. There is also a chain. And when cold there is more drag so you can feel it when the drive changes. Usually only when you "shift" to "N" or "R". Even with your foot firmly on the brake (so there is no drive from fake "transmission creep").

 

This is the best guess i have seen. My car never does what the OP was saying. If i start my car and after i back up about ten feet the ICE then starts up producing noise but does nothing to make me jerk backwards, but it does make a snapping noise.

 

Most people use the term "transmission" to mean a shiftable transmission, but any device that "transmits" power from one location to another is a transmission.

Tom

 

cool graphic

 

I have the same symptoms as the OP. this has nothing to do with engine hot or cold, sometimes it happens after my drive home. As soon as I shift in Reverse, there is that kick. It's almost like when you shift into R as the car is still rolling forward (But it actually isn't).

I also have waited 5-10 seconds before shiftinfrom D to R, but still there.

Posted via the PriusChat mobile app.

 

What’s the miles on it? Have you had it since new? (Wondering if someone might have used an alternate fluid in it.)

Easy first step, if it’s not been done: change transaxle fluid. May or may not help, but good to do at least once.