Do you put transmission fluid in the car while its running or while its off?

Answer 1

Good Question . The fluid level must be checked with the vehicle level and engine running at idle , Set park brake . Start engine . Then move the shift lever through all gear ranges Ending in NEUTRAL ( NOTE ) Incorrect fluid level readings will result if the vehicle has just been driven at high speeds for aextended period , IN hot weather in city traffic , or pulling a trailer if so let the fluid cool down about 30 minutes . Check fluid level at normal operating temp . add fluid a little at a time Do NOT OVER FILL ( Check LEVEL ON DIP STICK ) as to your question as for adding fluid if you can do it with the engine running sure just watch out for all those moving parts , or be on the save side and turn the engine off ,add fluid , start car , check fluid level , turn off engine , add fluid , start car ,check ,

NOTE: Check with your manufacturer's requirements, not all transmissions should be running when fuid is checked. ie: Ford 5R55 series and several other electronic transmissions will not read correctly when engine is running. Although the majority require the engine to running, many newer transmissions just need to be at operating temperature with the engine off when checking the level.

Some also require the engine to be running and the trans in park and some require the trans to be in neutral while engine is running.