Automatic transmission rolling backwards


#1

I just bought a 2009 Corolla for my 85- year old mother. She’s had the car 2 days and called to say that it rolled backwards when she was stopped for a light at the top of slight incline and the car was in Drive. She said her prior car (a 1995 Camry never did that). Is that normal for a car in drive to roll backwards? If not, what should I do?


#2

If the car rolled backward, that would indicate that she did not have her foot on the brake–and that is not a good thing. Yes, older cars could be held on an incline by the transmission–in some cases by applying a bit of pressure to the gas pedal–and in some cases without applying pressure to the gas pedal. But, holding a car on an incline by applying more gas was never a good idea, due to increased wear on the transmission.

However, on newer, more fuel-efficient vehicles (Hondas for example) it is considered entirely normal for the vehicle to roll backward on an incline if the brake is not applied. I suspect that the newer Toyotas are similar in behavior.

Try to get your mother to firmly apply the brake every time that she is on an incline, and she should have no problems. And, she should really enjoy the mpg advantage that a 2009 Corolla has over a 1995 Camry.


#3

Reply Deleted by self.


#4

This is normal behavior in modern cars. Your mother must get accustomed to resting her foot on the brake when the car is stopped. Most of do so at all times anyway.


#5

It happens a lot and it is normal. It isn’t recommended that you let it happen.


#6

I concur, this is normal.

The engine is connected to the transmisison by a device called a “torque converter” that is basically like a sliced bagel with vanes inside of each half and filled with fluid. When the engine is revved to accelerate, the front half of the bagel spins, the vanes drag the viscous fluid along, the fluid drags the back half of the bagel which pulls the car along. At idle there is very little force being transmitted through the fluid, so the engine is basically disconnected from the drivetrain, allowing the car to roll.