2009 Hummer H3T Alpha Owner's Manual - Page 256

5-20 Service and Appearance Care It does not take much fluid, generally less than one pint (0.5 L). Do not overfill. Notice: Use of the incorrect automatic transmission fluid may damage the vehicle, and the damages may not be covered by the vehicle's warranty. Always use the automatic transmission fluid listed in Recommended Fluids and Lubricants on page 6-12. Manual Transmission Fluid When to Check A good time to check the manual transmission fluid is when the engine oil is changed. However, the fluid in the manual transmission does not require changing. 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. To check the fluid: 1. Park the vehicle on a level surface, then shut the engine off. Let the vehicle sit until the transmission case is cool enough to touch. How to Check Because this operation can be a little difficult, you may choose to have this done at your GM dealer/retailer service department. If doing it yourself, be sure to follow all the instructions here, or there could be a false reading. • After adding fluid, recheck the fluid level as described under "How to Check Automatic Transmission Fluid," earlier in this section. • When the correct fluid level is obtained, push the dipstick back in all the way; then flip the handle down to lock the dipstick in place. 2. Remove the filler plug.