May I suggest you get a 5mm hex key on a 3/8" drive socket before you begin?

I also recommend replacing the copper crush washer under the pan drain bolt. I got to waste 3.5 qts of Mobil 1 Synthetic ATF @ $5/qt because I forgot the washer and had a slow drip of ATF from the drain plug.

You'll need up to 7.3 qts if you totally flush the entire system.

I appreciate for your input. I rebuilt the transmission about 21/2 years ago. I believe they used dextron III fluid. Is it ok to use ATF?
Please advise..

Sincerely; Romeo

Hi Dextron 3 is just fine for your veh.joeym

Dexron III ATF is fine, and you don't need synthetic. Another handy tool is a remote starter switch to bump the starter so you can move the torque converter drain plug to where you can get to it. There are two terminals under the hood near the battery where you can attach the remote starter switch. The switch is $5 or $10 or so. The torque spec for the two drain plugs is 10 ft lbs (14 Nm) and the transmission pan bolts tightenly evenly to 6 ft lbs (8 Nm).

I appreciate for your input guys.

Best Regards:
RomeO

If you don't want to mess with a remote starter you can put a socket on the crank pulley nut and turn the motor manually. This would elliminate any wear/tear on the starter/battery.

The drainplug for the torque converter is also 5mm.

There are 13 different brands of ATF that MB recommends. The most common one's are Castrol and Pennzoil Dextron III.

It doesn't much matter what brand of Dexron III you use. GM owns the trademark and they watch the quality of all licensed canners/marketers/brands like a hawk.