I bought my 2009 Elantra Touring (with automatic transmission and 17" alloy wheels) new in August 2009. Since then, on several occasions (about 6 or 7), while parked on a slight incline with the transmission in park and the engine off and key removed, the vehicle has rolled down the incline.

It has done this while parked face down the incline and face up (on my driveway). While rolling there was a very audible ratcheting sound coming from underneath the car. In all cases I was forced to use the brakes to stop it. Subsequently I turned the car on, moved the shift lever to drive, and then back to park where it held fine after that.

The same thing happened once when my wife was driving the car (so its not just me and the way I am engaging park).

Needless to say this has been quite disconcerting ! After about the third time I took it right to the dealer. They ran diagnostics on the transmission and all checked out fine. They tried to reproduce the problem but could not. They even had me drive with the tech in the passenger seat where we tried parking on various inclines but could not reproduce the problem. Of course I knew it would not happen then given the low frequency of the problem when I am driving the car.

The tech told me that the only thing they could really do was to replace the transmission and they really did not want to /could not do that without first reproducing the problem.

Has anyone else seen that happen on the automatic transmission or have any ideas about what I can do about it (other than engage the parking brake which is what one of the service guys suggested )? I am not sure where to take this next as I think this is not normal and a somewhat dangerous condition. Thanks in advanced for any help.

 

When you put the transmission in PARK basically a pin is inserted in a slot and that locks the trans from moving. If you've ever put a car in park while it's moving you would hear a "click, click, click" as the trans tries to set that lock pin but can't because the wheels are turning. That may be happening in your case. You may be unknowingly putting the car in PARK while it's still moving slightly.

You probably aren’t going to like this advice but I agree with the service guy. You should ALWAYS use the parking brake when stopped, even with an automatic. This means the car is being held in place by the brakes and not the locking pin in the transmission. Especially on a hill where the weight of the car will try to turn the trans against the pin on an incline.

 

I am sure it is safest to put on the parking brake each time but I have never done this on any other car (aside from manual transmissions) that I have driven over the course of 35 years.

Similarly, that park problem has never happened on any car in that same driveway over the last 30 years - and there have been quite a few cars on that driveway (btw it just has a very slight incline, not much - this is Illinois and remember that we are the flattest state )

Given it happened to my wife as well it must be some quirk with that automatic transmission or maybe just that particular unit. Luckily it happens as soon as I take my foot off the brake when I put the car into park so I am sitting in the car and can apply the brakes.

But seriously, hopefully I will remember to apply the parking brake each time so it doesn't roll over somebody someday.

Seems odd that the transmission was designed so that it could be in park without that pin in place. I still think something is wrong.

Thanks for your advice.

 

It is odd, and on a slight incline it should be able to hold. I've driven heavier cars that have held (not a big fan of parking brakes because on some cars they tend to warp the rear brake drums while they're hot). Ive seen where the pawl or "pin" was broken and not engaging entirely. Are you able to simulate the problem by pushing it while in park on a level surface? Odd that they're only solution was to replace the transmission and not take it apart and inspect the parking mechanism or at least drop the pan and see if there's any broken pieces in there, but then of course, I'm not a certified Hyundai mechanic. Maybe some of the real techs on here can offer better insite.
On steeper inclines you should be using the parking brake because there would be considerable wieght on the parking pawl and could cause it to snap.

 

Not just safe, but it keeps strain off the pin/pawl. Also, by doing this youll likely find its easier to get into gear.

 

MARKMAYLE - I'm a bit surprised that Hyundai engineering has not contacted you about this issue. Any automatic transmission that has reportedly not locked into the Park position - FOR ANY REASON - is a potential safety issue. You noted this has happen not just once but 6 or 7 times to you plus also to your wife.

Over the years there have been many ParkPawl safety recalls by NHTSA requiring auto manufactures to take necessary steps to prevent this occurence. Using the Parking Brake is not a satisfactory solution! Belts and suspenders at best.

One of the many Park Pawl recalls is the BMW Recall #05V504000 dated about 2005. Not many cars involved but thay all needed repairs to Park mechanism. GOOGLE it.

Park Pawl concerns are not unique. Being an assembled mechanical item sometimes the parts are not installed or adjusted as designed. Nothing is perfect.

If you are absolutely sure you have correctly pushed the gearshift lever into PARK after the car is stopped and - regardless what your dealer claims - you might consider contacting Hyundai (not just the dealer) then NHTSA if Hyundai gives you anything less the 100% immediate action and satisfaction.