Having same issues as many other with the wipers not making full contact with the windshield so after trying new blades first I decided to get new wiper arms.

I had no problem getting the old arms off thanks to various posts on this forum but I seem to be having problems getting the new arms pressed down onto the splined/threaded part fully. Any suggestions?

 

my new arms were hard to get on. not sure if its true with all of them. i just wiggled them as i tightened. careful not to over torque the bolts.