Aanybody know what the set screw and lock nut are for on the top of the shaft housin just in front of the weep ole in the top. on a 1963 3.8 thanks Dwight

 

Any chance of a photo and we can then know exactly what you are trying to identify.

 

From memory, it holds the bearing cluster in place.
You remove it to press the unit out when rebuilding.
It is not tightened up when installing the bearing cluster, if it was, the pressure would distort the outer race and cause binding.
There is a place in the bearing cluster that the set screw fits into, it's just lightly "set" to hold things in place, and the lock not is to keep the set screw tight in the housing.

If you rebuild the pump, I think the new cluster is a tight enough press fit, where the set screw is not needed, I don't think there is a keeper hole for it anymore.

 

thanks that makes sense. this is a new pump from Moss screw was loose and nut also. no slot or allen so i fingered it tite and set the nut. thanks. i wonder why the weep hole is on top...seams like te bearing will be wet before the water that leaked through the seal will get out...who ever called the cowl vent opening parts Rube Goldberg. must not have the power stearing pump on the back of the generator, or the brake vacume booster on the far corner of the engine compartment, 5 feet from the master cylinder...i also have an ac system above the gen. and ps pump. that is comming off as i speak. any market for the whole unit? thanks again Dwight '63 MK2 3.8 auto.