Automatic Transmissions when in Park

Discussion in 'Chevy Truck Talk & GM News' started by McClintoc, Aug 6, 2014.

  1. McClintoc

    McClintoc ɹoʇɐɹǝpoɯ Staff Member 3 Years 1000 Posts

    I have a quick question about automatic transmissions when the vehicle is in PARK. What kind of state are they in and by that I mean, are there any gears engaged at all?

    The reason I ask is, my dad was visiting over the weekend and one day when I went to pick him up at his hotel, we noticed the front tires of his 2013 Ford Expedition were up on TOP of the concrete parking block. Upon further inspection, we found his rear bumper was messed up. Fortunately, no other damamage, unless the transmission is messed up, which is what I am trying to figure out. He went back into the hotel and talked to the front desk and sure enough a drunk driver had come through the night before. The hotel called the cops after it happened and my dad called the cops that morning and sergeant showed up in less than 10 minutes to take a statement and give my dad the case number. The drunk asshat had already been arrested.

    So, my question is, should my dad be worried about the transmission? He drove it home the next day (3 hours) and said it did fine. I am curious what is going on inside an automatic transmission when it is in park. His truck was pushed with enough force to get it up on top of the concrete parking block. Does it hurt an automatic transmission to roll when in park?
  2. Conlan Rose

    Conlan Rose Epic Member 5+ Years 1000 Posts

    While in park there is a prawl that locks the tranny/drivetrain in place if in park the wheels wont roll when moved, but if the wheels were forced to move it may have damaged the prawl but it wouldn't effect any other part of the tranny.
  3. Sierraowner5.3

    Sierraowner5.3 Epic Member 5+ Years 1000 Posts

    being as it was the front wheels pushed up on the block, they should have rolled. on rear wheel drive vehcials ( or 4x4s in rear wheel) the park position only locks the rear wheels. the rear wheels may have just slide on the ground.

    he would know if the pawl was broken, because the ford would not stay in one place.

    someone else correct me if im wrong.

  4. RayVoy

    RayVoy Epic Member 5+ Years 5000 Posts

    Only one rear wheel is locked to the transmission (open diff) Alex; but, your right, it would not stay on a hill if the PARK pawl was broken. It would roll down hill.
  5. McClintoc

    McClintoc ɹoʇɐɹǝpoɯ Staff Member 3 Years 1000 Posts

    Other than the pawl being broken, would it have messed up any of the gears?
  6. doublecardan

    doublecardan Member

    The parking pawl is very strong so its probable that as was said the rear tires were pushed and the fronts rolled. A telltale would be rubber marks on the front of the tire but that is moot now. No gears would be hurt but if the pawl was damaged a part of it would have been in the trans and making some noise. It does not sound like it and the old man should be fine.
  7. RayVoy

    RayVoy Epic Member 5+ Years 5000 Posts

    No, PARK is the same as neutral, with the addition of the parking pawl.
  8. McClintoc

    McClintoc ɹoʇɐɹǝpoɯ Staff Member 3 Years 1000 Posts

    A little update: the Expedition is in the shop and the drunk guy's insurance is covering all the repairs. My dad and the mechanic both think the transmission is OK so that is good. He ended up with a Hyundai Veloster as a rental, LOL.
  9. Chesters

    Chesters Well-Known Member 2 Years ROTM Winner Gold Member 1000 Posts

    In try to stay on subject. I have a 90 k1500 4l60e. When I start the truck in park I cannot get it to change gears. When I move it to the first key point. And put the truck in neutral, I can start the truck then move the shifter lever to what I need. Is there some kind of safety interlock that is preventing me from starting in park then moving to a desired gear?

    Thanks for any help.
  10. Chesters

    Chesters Well-Known Member 2 Years ROTM Winner Gold Member 1000 Posts

    Sorry that was a 1996 k1500 with a 4l60e.

Share This Page

Newest Gallery Photos