Mindlessly, sometimes I get in a hurry and turn my 2006 Forester off while sitting still, but not in Park. In other words I shut it off in drive before putting it into park. I have a friend who tells me this is not good for the tranny and awd. Although, it bugs me that I sometimes do it. I cannot see how this would harm the car. My friend insist that it can cause the tranny to “back up on itself”, in other words the torque being held back has to go somewhere and since I am holding the brake when I typically do this, it causes the plates in the transmition harm. My arguement lies with how a subaru torque converter works. (http://www…onvert.htm) It is a turbine system which uses ATF to engage. At idle the tubines should not be engaged thus if there was an “backup of torque” it would just cause the turbine to spin freely. Therefore, causing no harm. So I guess my question is: Am I causing damage by sometimes shutting it off in Drive or is my friend got me worried for no reason. I look forward to your replies. Thanks
If your vehicle is stationary, you can shut the engine off in whatever transmission position you want. Its not harming a thing.
What you’re doing should be totally harmless. As long as you put it in P before walking away. And your logic is excellent.
Yes, there is a load no the torque converter when you’re stopped with the car in D and your foot on the brake. The converter simply dissipates it as heat energy (via generation by the turbulance in the TC fluid) and it’s released into the surrounding atmosphere by the tranny cooler. That’s exactly what a TC is designed to do. If you turn the engine off with the tranny in “D”, the turbulance in the converter simply stops, and whatever heat energy is in it simply dissipates via radiation, exactly as it would if you put in in “P” first.
The thing I’m unsure of is if the parking pawl can enegage cleanly with all the parts stationary. I’d feel better if Transman stopped by.