What is the correct procedure for checking manual transmission fluid?

The correct procedure for checking manual transmission fluid involves removing the fill plug. This is essential because manual transmissions typically do not have a dipstick like some automatic transmissions do. By removing the fill plug, you can assess the fluid level visually or by feeling for the fluid with your finger. The fluid should be at a level that is even with the bottom of the fill opening. If the fluid is low, it indicates that a refill is necessary to ensure proper lubrication and functioning of the transmission.

The other methods mentioned are typically not applicable for manual transmissions. Using a dipstick is relevant for automatic transmissions. Holding the vehicle at a specific angle or checking fluid levels with a gauge may not be suitable or provide an accurate reading for all manual transmission types. Therefore, removing the fill plug is recognized as the standard and appropriate method to check the fluid level in a manual transmission.