Shifter doesn't work so I am getting ready to dive into tranny,p.o was a hack the bike came with s used shifter shaft in a parts bucket. So I don't know what he did to it but will need some help 1970 xlch ironhead shifter on right side

 

If you don't have one, get a factory service manual, available from your local dealer. There are also on-line parts websites where you can see exploded diagrams of your bike, as reference material, although theere is also a factory parts book which is worthwhile.

 

Gotta pull the trans. to get to the shifter and mechanism. Depending on what is wrong, you will have to check the whole pawl carrier and pawl, plus likely inspect the shift forks and what not.

While you're in there, since it was a hack previous owner, I would verify the gear spacing and shaft end play. Also carefully carefully inspect the gears for cracks and faults, as a couple of them have known issues that can cause them to break.

I would also carefully inspect the countershaft boss on the inside of the case for any signs of cracking or damage. Very common.