Transmission fluid change

Changing the transmission fluid on the TR-3650 is a pretty simple process.
You will need

Put the car up on jacks or ramps. When using ramps, you may need to jack the body up a little to gain some clearance.

Using a 3/8" square drive ratchet, remove the drain plug, located on the bottom and left of the transmission, and drain into an oil pan.

After the fluid has drained, install the drain plug.

I use a large gear oil pump. I take the pump apart and use the cap from the ATF bottle and cut a hole into the cap. Then I reassemble the pump with the new cap in place. Now the pump will securely fit the ATF bottles.

Next loosen the fill plug, it is located above the transmission cross member on the passenger side.
I have found that using a 1/2" ratchet with a 3/8" adapter works best. It gives you a little bit of clearance and a little more reach.

Insert the pump hose into the fill hole and pump in the ATF fluid. The Tremec 3650 now calls for 102 ounces of ATF fluid. So I put in 3 quarts and six more ounces from the fourth quart. Install the fill plug and let the car down.

Done.