I want to put a pulley on the front of my D4 7U. 
what is the bolt pattern, I’m trying to make my own drive shaft for a hydraulic pump. 
any help will be appreciated 
thanks, Oscar

why dont you call a couple of salvage yards , (general gear in Idaho )

the way to do it get a piece or thin card board like a cereal box and use it to get the bolt pattern of the front pulley. then use a ruler to measure the pattern the same as you would for a wheel rim PCD(pitch circle diameter) based on the number of bolts. to find the centre distance across 2 holes you measure from the edge of one hole to the same edge on the other hole and you have the centre. you can also use a set of dividers & a rule and take the measurement directly. the bolt pattern is probably a SAE type pattern since cat engines are American and just about everything American designed at that time period was to SAE standards.

i wouldn't try and make your own shaft as they need to be in perfect balance or they will vibrate and destroy themselves or something else. this is work to be done by a drive shaft workshop.
IT IS NOT A DIY JOB.

if you have a parts book for your machine or the type 44 hydro control it details the drive shaft uni joints if you search online for uni flanges by part number and can find the national stock number listing you may find the info you want.

also i have seen the generator used as a adapter to vee belt drive a small hydro pump. it would be a simple job to have a adapter and shaft made to use the original generators drive gear and belt drive a pump and that is a home machine shop job.

I should have the front pullley and u-joint drive shaft assembly for D4