I copied for website. I hope I did it right.
Things You'll Need:
Hydraulic lift or oil change bay
Make arrangements to use a hydraulic lift or underground oil change bay. Keep in mind that the transmission fluid must be hot to be checked accurately, so you'll need to drive your HHR directly to the lift or bay after about 15 minutes of driving. This may complicate the timing if you're using someone else's lift or bay, so plan ahead and make an appointment if necessary. If possible, divide your 15 minutes of driving time between side streets and high-speed highways. This will force the car to go through all its gears during the drive, which will better distribute and warm up the transmission fluid.
Park the car over either a lowered lift or an open underground oil change bay. Leave the engine running. If you're using a hydraulic lift, make sure the lift arms are positioned under solid parts of the auto frame and use the controls to raise it up. You'll need to raise it high enough that you can get underneath it comfortably, but low enough that you can reach the transmission case.
Look at the bottom of the transmission case at the front of the HHR. You should see 2 removable plugs labeled "Drain" and "Check." Position a drip pan beneath the Check plug and unscrew the plug.
Editor's note: This is incorrect: The fill plug is on the top of the case. The check plug is on the side of the case, passenger side. There is no drain unless someone installed one after-market. (see illustration in post #7)
When reinstalling the pan bolts torque them to 106 lb INCHor you will distort the pan.
Observe the flow, if any, of transmission fluid coming from the plug. If you get a stream of transmission fluid, there is too much fluid in your system. If nothing comes out at all, there is too little fluid in the transmission. If you get a slow, steady drip, your fluid level is correct. Replace the Check plug. Make sure it's on tight before lowering the car or driving away.
Tips & Warnings
You won't find this information in the owner's manual of any Chevy with a sealed transmission; you'll only find a recommendation that you take your car to an authorized dealer for transmission service.
If you jack up your HHR with a floor jack to test the transmission fluid, all the fluid will run to 1 side of the transmission case and you'll get an inaccurate reading.
Automatic Transmissions and Transaxles; Tom D. Birch and Chuck Rockwood; 2009
Auto Repair for Dummies; Deanna Sclar; 2008
Chilton's Automatic Transmission Diagnosis and Repair: Auto Transmissions and Transaxles; Chilton; 1998
Written by Josh Crank