Get a good book & follow directions to disasemble it. You cannot remove the upper shafts with out dropping the cluster (counter shaft) gears down to the bottom of the case. Used trans. like this are easy to find used. I would get a used one & use it or disasemble it for parts. The seals & brgs. are available at any parts store. The ones in light duty trucks are the same except some variations in the rear output shaft & some had the emerg. brake on the back. The ones in the light duty trucks are usually in good shape as they are not worked as hard as the ones in the medium duty trucks.
George
