Torque wrenches

I have a Snap On torque wrench for higher torque stuff. It is not the type where you crank the handle, it has a knob on the side with a dial that turns. Had Snap On guy that I know from the track check it, it is calibrated.
But...and this is me just overcomplicating my life..changed the trans fluid in my Allison trans. Pan bolts are 18ft lbs. My above mentioned Snap On starts at 50ft-lbs.
Any suggestions?

18 POUND FEET? Are you sure? That seems awfully tight for sheet metal. But then, I bet that has that modern pan gasket with the steel core.

That would be what I call "good and tight" with a short 3/8" ratchet.