New uj's last an awful lot longer if you use a press and / or sockets and a vice to install them. A clonk with a copper hammer evens things out when your finished if ones a bit tight. if you simply cannot get one clip in, take it apart because a needle has almost certainly dropped.....
Lol, years ago I used to do 20 ujs in an hour using an air rivetter, good times ;-)
Remember you can also buy uj kits at any half decent bearing supplier, equal or better than oe.