Auto Parts: binding linkage and pivots, windshield wipers, chevy malibu

Question
I have a 97 Chevy Malibu my windshield wipers got twisted together so when checking the linkage broke off went to junk yard got another one.Once we put them on as long as the wiper arms are not on the arm and everything is working but as soon as we put the wiper arms back on the and turn it on the bushels pops aloose please help me if you can. Thanks

Answer
    If you are using the original wiper arms, then the problem is probably simple.  There is a little tab on the underside of the arm which retains it on the splined barrel of the post.  This has to be withdrawn in order to remove the arm from the car.  Either this tab is not being fully extended to grab the barrel, or it is bent or damaged.  If the arms have been replaced with new ones, I would be suspicious as to whether or not they are the correct ones.  Getting the arms and the wiper transmission at the salvage yard from the same car would have eliminated the possibility of a mismatch.  Remember, GM doesn't make wiper arms, they buy them from someone who makes them to spec.  I have seen a wide variation in these items, and sometimes you have to fiddle with them to get them to work.  Look at the underside of the wiper arm and you will see the little tab I am talking about.  If it looks damaged, get the new one from the dealer, and take the old one with you to make sure you get the right one.