When you shift into “P” first, lift your foot of the foot-brake, and then engage the parking brake, the weight of the car rests on that tiny metal bit we call the parking pawl. That’s not great. When you do this, you will hear the unpleasant “clunk” when shifting out of “P” later.
Is it wrong to let the car's weight rest in the parking pawl?
Well, parking pawls can break. It might not look like much, but this little broken piece can be nuisance to fix. Sure, it’s a tiny metal bit, but that tiny broken piece can jam up some crucial parts in your transmission.
Sometimes, you might even notice people shifting into “P” at traffic lights. It’s not a great habit.
So how do you avoid the “clunk” sound?
Take the following steps when parked on a hill.
1. Bring the car to a full stop.
2. Keep the foot brake pressed.
3. Shift to "N".
*Now all the weight is on the foot brake.
4. Engage the parking brake.
5. Lift your foot of the foot brake.
*Now all the weight is on the parking brake.
6. Press the foot brake. (to prevent reversing)
7. Shift the gear into “P”.
8. Lift your foot of the foot brake.
*Now all the weight is on the parking brake while the parking pawl acts as a fail-safe if the parking brake fails.
In short, it is better to let the weight of your car rest on the parking brake than the parking pawl (especially on a hill). You wouldn't want to have a broken parking pawl in your transmission.