Yes, there are expansion plugs (freeze plugs) on both sides of the engine block and at the rear of the engine block between the engine and transmission. There are also a couple in the ends of the cylinder heads.
With all that said, I would like to add that many times with that engine, the heater tube and connecting hoses can leak and be mistaken for a rear expansion plug leaking. I would definately check this before pulling the transmission out.
There is a tube that runs from the back of the water pump under the intake manifold and out the rear of the engine where it hooks up to the heater hose/heater core. This tube has a small hose connecting it to the back of the water pump. There is also a hole in the back of the engine block that will allow antifreeze from under the intake manifold to leak into the transmission bell housing area. When this tube or hose leaks, it often gets mistaken for a leaking rear expansion plug.
It is very easy to check for this. Remove the serpentine belt and remove the alternator and look under the intake manifold down in the "valley" between the cylinder heads. If there is antifreeze in there, the hose or the tube is leaking. Look at the picture below. Item #3
is the tube and hose assembly I am talking about. Usually, just the hose is leaking. It should be replaced with a short piece of SILICONE heater hose. On some of the vehicles, there are 2 hose clamps. On others, the end of the hose that is attached to the tube has a crimped collar on it. If yours is like this, you can fix it by carefully cutting the crimp collar off and replacing the hose using band clamps. (screw-type)
Also look for antifreeze leaking into this area from the front intake manifold runner. They tend to leak on the front runner near where the thermostat housing is located. These will also leak into the valley area and run out the back of the engine. If the manifold is leaking, chances are it is warped. DORMAN makes a replacement intake manifold kit just for this purpose because it has been so common. It is also very easy to check for this with the alternator removed.
The DORMAN part number
for your vehicle is 615-178
(See second picture below)