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Drift back/forward on incline/decline when shifting into reverse. This happen to you?

7K views 16 replies 13 participants last post by  Norton 
#1 ·
Every time I park on incline or decline and shift into reverse/drive my Volt drifts forward or backwards about an inch (or so) despite having my foot hard on the brakes. Curious if this is just my own issue or other experience it. Or is this a Volt quirk I need to get used to. The first time it happened I freaked out because I thought I was going to hit the wall I parked pretty close to.
 
#2 ·
Yeah, same here, was scary the first time. I just pulled over to answer my cell phone and did not engage the parking brake.
Do you use the parking brake? I tried it once and the car still moved a bit.
 
#3 ·
Never had that happen, but if on an incline/decline I always use the emergency brake after I park. When starting up again I go through the sequence: Put fuoo on break, start Volt, put in gear, release emergency brake, release foot break and go. So at the point I put it in gear I also have the emergency break engaged.
 
#7 ·
The owner manual seems to imply that you should avoid this, but it is nice to have when you forget to disengage the parking brake. On page 9-32:

Notice: Driving with the parking brake on can overheat the brake system and cause premature wear or damage to brake system parts. Make sure that the parking brake is fully released and the Electric Parking Brake Light is off before driving.

Automatic EPB Release
The EPB will automatically release if the vehicle is running, placed into gear, and an attempt is made to drive away. Avoid rapid acceleration when the EPB is applied, to preserve parking brake lining life.
 
#8 ·
It's not an automatic, automatic release. I know this because I walked down to the parking structure and watched the valet try to move my car. The brake was on and he obviously couldn't figure out how to release it, so I saw the rear end lift up pretty good before it starting backing out at a pretty quick rate.

I always engage the brake. My mind decided a long time ago that I should put more strain on the brake than on a transmission. Not sure if that is a correct way to look at it, but it's the way my brain works I guess. That little roll back freaks me out.
 
#9 ·
Parking brake use

It might also be a good thing to note that "Never Using" the parking brake can cause it to bind up from lack of use. It should be activated on purpose once in a while to assure that the mechanicals don't bind up from lack of use. The system activates the rear caliper mechanically, which is subject to a lot of road crud.... :)
 
#10 ·
I'm picking my '13 Volt this Saturday.
The lack of a proper Old School Mechanical Emergency/Parking Brake is one of the things I hate about a Volt.
When the car goes black because of an EMP or the Master Cylinder goes south, I want an emergency brake that does not require electrical power.
I have no idea how the Volt got certified with an Emergency Brake that requires electrical power.....

Back to the OP's question: Say What????? If you have your foot firmly pressing the brake pedal the car still moves forwards or backwards an INCH or so when putting it in gear???

How is that explained???
 
#11 ·
The volt has a Compound Crank rear suspension, which is just a fancy name for trailing arm. If you look under the rear of the volt, at the rear suspension, you can see how it works. When the parking brake is set there is no relative angular motion between the wheel and the rear spindle/suspension. If wheel torque is applied (such as parking on a incline or decline), the torque will transmit into the rear suspension and force the Compound Crank to start to rotate. If thr car is trying to go forward, the suspension will rotate on its pivot and cause the rear of the car to squat lower, and the call will move forward a slight amount as the crank arm is pivoting. Rest assured, there is a mechanical stop to this pivot moment and the car will only move forward a small distance and stop. If you are on a upslope and set thr parking brake, the car will move slightly backwards and the rear of the car will raise slightly as the crank and pivots down. This is almost exactly how my old 78 VW Rabbit rear susenion worked. Living in Seattle at the time, I learned at a early age how to use the parking brake hand lever to hold the car stationary on a hill as I worked the gas and clutch pedals with my feet. I found it amusing of the rear of the little Rabbit would bounce up and down as I was working the parking brake lever on hills.

I good design feature of compound crank suspension is that it naturally opposes the dive forces under braking, since braking torque in the rear suspension wants to make the rear of the car to down, and at the same time the natural dynamic forces of braking wants to make the rear of the car go up. The two forces counteract each other and helps keep the car level.
 
#16 ·
I just got a 2014, and I noticed this the first time I parked on a hill (facing uphill). I had the brake pushed down all the way, and shifted the car into drive to go. The car rolled slightly and I just cringed at the feeling of gears mashing together. I just felt like the car was in pain. Are you sure this isn't some backlash in the gears on the drive unit?
 
#12 ·
Good to know Eric.
I too noticed that my volt traveled a little bit after shifting into reverse. I also agree with the other poster in regards to the all-electric brake. Its just weird to press that small button to engage the brake. Plus I can never remember if I need to push or pull the button. I can just see me in the middle of some event, first looking for a hand brake and secondly-- pressing and pushing the button.
 
#14 ·
The way I remember is, before they put a petal on the E Brake, it had a handle to pull to set the brake and twist and push to release, so I pull the button to set the brake. But you have to be older than a certain age to remember that.
 
#17 ·
FYI,
There are no gears that get shifted in the Volt transaxle. Everything in always engaged. No reverse gear at all.
Except for the Parking Gear Pal, a pin that engages into a slot. It has play and allows some movement of the car.
If it is carrying the load of a car on a hill, it will make a sound/feeling when the pal is pulled out of Park.

Some remedial instructions may be needed here:
>Did you set the 'Parking Brake' before shifting into 'Park Gear'?
>Did you turn your wheels towards the curb the correct way,,, as taught in Driver's Ed long ago?

(Most probably just rely on the Park Gear in all circumstances, thus the noise/feeling of releasing Park with a big load on it.)
 
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