ive searched before asking but no dice, i have a 97 f150 4x4 auto w/84k miles. i have been parking on hills lately(average hilly streets) when i put the truck in park it rolls until i put the brakes on. it does this in forward and reverse. i tried jockeying the shift lever to make sure its in park to no avail. the truck shifts and drives perfect and has full (looks) fresh fluid. any ideas? just called the dealer and they said there were no outstanding recalls on this truck.

 

The tranny shouldn't be used to hold you on a hill anyways.

1) Put the vehicle in the desired spot. Turn wheels away from curb on uphill, toward curb on downhill.

2) With the vehicle still in gear, being held by brake pedal, engage Parking Brake.

3) Shift into Nuetral and remove foot from brake pedal.

4) Shift into Park

Parking on a slight hill without using the Parking Brake means the Auto transmission is holding the vehicle in place. When a vehicle in this situation is put back into gear, the shift is usually accompanied by a large "BANG".

Too many 'bangs' and there ain't nothin left to hold nothin.

Using steps 1 thru 4 mean:
The Parking Brake is only thing holding the vehicle.
This is accomplished by shifting into Nuetral(eliminates the tranny) and taking your foot off the brake pedal (eliminates the brakes)

The transmission in Park is then the second line of defense in the event of Parking brake failure.

The 'tires into the curb' is the third line of defense after the Parking Brake and Transmission.

This is how I've always done it so, I have never known whether any auto transmission I've ever owned would hold on a hill or not.

If the truck rolls in Park on even slight inclines, something has to be fixed eventually.

 

Number one. When parking on hills, you should always apply the parking brake prior to putting the truck transmission in Park. (Put the truck in neutral, apply the parking brake, the put the truck in park). This relieves the pressure being put on the Park mechanism in the tranny. When you get ready to leave, put the truck in gear before releasing the parking brake.

 

ill take that advise. any idea why it would do that in thew first place though? i have had other autos that i have parked there with no probs. any sign of impending damage?

 

From what I understand there is a tab of metal about the size of the tip of your thumb that holds the vehicle while in Park. Has your vehicle ever been towed when the tow-er didn't have access to a key? I seen seen a vehicle dragged around to be put in position for a tow hook-up.

I had a tow truck guy try to hook my front-wheel drive Windstar from the back because he thought it was a rear-wheel drive Aerostar, until I stopped him. If I hadn't, I'd probably be rolling all over the place in Park too.

If it was me and the truck shifts ok and the OD light isn't flashing, I would just start using my Parking Brake religiously, flat and hilly. Some people do that anyway.

 

There is a pin that pops out to hold the vehicle. the whole mechenism is completly mechanical so a malfunction wouldn't pop up as an error and make the o/d light flash. i know people with older vehicles that have broken the pin and carry a log arround to fix the problem How Stuff Works has more info on this.

 

thanks guys, i appreciate it.