Just in front of the engine where the transmission joins, on the bell-housing right on the bottom there is a small plate with 4 bolts. Take it off you will see a blanking plug on the end of a pipe. Screw your pressure gauge into it..That is the main torque pressure from the pump..but if you have lost complete drive in both directions my money would be on the mounting plate the toque converter joins onto the engine flywheeel.. they tend to completely shear and it a very staright forward in replacing..Just roll the engine out and fit a new mounting plate.