Russ Johnson
Equipment Expert
Ralph, call me.
I did something very similar. I cut some little shims and ending up stacking them and going little by little until I could put a 2x4 in and then continue with the shims against the wood. (Wish I could post a clearer picture, file size was too large so I had to screenshot my photo library and crop it that small, but you get the idea.)You ever see how pulleys have another set of holes in them, you remove the bolts that hold the bushing in place and put them into the pulley and tighten them and that helps pull the pulley off of the bushing/shaft.
I wonder if you could so something similar?
Maybe put a nut with a large washer between the gearbox plate and the engine with a bolt going from the gearbox side into the nut so when you tighten the bolt into the nut, it pushes the bolt through it touching the washer or other piece of metal larger than the bolt so the pressure is spread out some and with several of these on sides of the pump, maybe that will slowly push the gear box off of the engine?
Kind of like using a gear puller but different as you are pushing from behind the gear box against the engine.
I don't know of the engine itself can handle the pressure, maybe it might using large washers or small plates of metal as the bolts themself are small and might punch through the engine, plates or large washers might avoid this.
Just an idea.
Good luck.