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 Isuzu 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 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:

1. Remove the filler plug.
2. Check that the lubricant level is up to the bottom of the filler plug hole.
3. If the fluid level is good, install the plug and be sure it is fully seated. If the fluid level is low, add more fluid as described in the next steps.

Here is how to add fluid. Refer to the Maintenance Schedule to determine what kind of fluid to use. See Recommended Fluids and Lubricants .

1. Remove the filler plug.
2. Add fluid at the filler plug hole. Add only enough fluid to bring the fluid level up to the bottom of the filler plug hole.
3. Install the filler plug. Be sure the plug is fully seated.