A good time to have it checked is when the engine oil is changed. However, the fluid in your manual transmission does not require changing.
Because this operation can be a little difficult, you may choose to have this done at your GM dealership service department.
If you do it yourself, be sure to follow all the instructions here, or you could get a false reading.
Notice: Too much or too little fluid can damage your transmission. Too much can mean that some of the fluid could come out and fall on hot engine parts or exhaust system parts, starting a fire. Too little fluid could cause the transmission to overheat. Be sure to get an accurate reading if you check your transmission fluid.
Check the fluid level only when your engine is off, the vehicle is parked on a level place and the transmission is cool enough for you to rest your fingers on the transmission case.
Then, follow these steps:
Here is how to add fluid. Refer to the Maintenance Schedule to determine what kind of fluid to use. See Part D: Recommended Fluids and Lubricants .