Just changed the trans fluid/filter in our '00 Durango and I see the fluid must be checked with engine running and trans in neutral. What is the difference in checking it in neutral vs park? Thanks!

 

The pumps engagement and fluid hydraulics.

 

yup, what hydra said, with the pump not running, the fluid level will be wrong, and the pump doesnt run in park

 

Checking your tranny fluid level:
1) Drive for ten minutes to get the fluid running.
2) Park on a level surface. Shift the shifter through all the gears for a few seconds each gear. From Park to 2 back to Park. Then put on foot brake and set the transmission to Neutral.
3) Make sure the foot brake is fully engaged before opening the hood and getting out of the D.
4) Open hood and check the fluid level by taking the dipstick out and wiping in down then reinserting it back into the fill tube. Let it rest for a few seconds and take the dipstick out again. The level should be in the "Hot" hashmarks. If low, fill gradually until the level is in the "hot" hashmarks. Do not overfill. Overfilling make cause foaming and foaming is not good.