Lazy wiper arm

The driver side wiper arm on my '72 doesn't keep time. These wiper arms are ridiculous to find and buy. Is there any trick to tightening the fit on my wiper arms. I did buy a new wiper arm transmission set, so it must be the arms fit to the knurled spud.

The 71-3 arms have a slotted / elongated area

I don't think there is any way it could slip

I had a similar issue, and I found there is a pressed on piece that was slipping.

the picture attached shows the parts I'm talking about, but keep in mind, the small part is broken off the rest of the shaft.

and if that the case, the pressed in part is stripped, you will have to replace the whole wiper transmission (its an easy job not complicated)

and the second picture shows the enlarged area in the back of the wipers that Don is talking about, that's used for summer /winter settings, I guess that could slip also.

I've seen the stud spin in the transmission arms. I've welded them for local guys. They have to come out for inspection.

Check the linkage bushings to see if they are worn. Chuck

It is slipping in the winter/summer adjust area. It wont stay in the summer position.

sounds like the spring in the wiper arm then claps on the bracket, is broken or bent out of place.