Transmission Fluid Check

[bbman]

I have a '98 Corolla. I have looked over the owner's manual from front to back and checked out the transmission dipstick on the car. Nothing clarifies whether one is to check the transmission fluid with the engine on or off. Some of the DIY stuff on the web says to do it with the engine on, but these sites also have no idea about the separate differential in the transmission either. As a result, I don't trust them. Any certified mechanic clear on this issue?

[fishexpo101]

To check fluid level (applies to 3-speeds and 4-speed automatic transaxles)
- transaxle at operating temperature
- car must be running in Park
- measure on level ground.

Fluid level should be in the "hot" range, between the two notches on the dipstick. Add fluid as required through dipstick tube, do not overfill.

For the ones running 3-speeds with the separate differential reservoir - level check via the fill hole on the side, fluid level must be just within the opening of the fill hole (stick your finger in there and feel for fluid).

[bbman]

Thanks. Is it okay to check the fluid right after I start the car? My dipstick has separate "cold" and "hot" measurements. Is there a reason to only check it in normal operating temperature (I'm assuming this means the car is warmed up)?

[fishexpo101]

Sure, though I found that level to be slightly variable, due to moisture in the fluid, not being properly circulated through the system, etc.

But it should be close enough - especially if you check a couple days in a row to average out the cold readings.