I have the original plastic wiper arm on the rear of my '08 T&C, but the base cracked so it would slip on the motor shaft. Everything I've read tells me that this original arm, Mopar 68028437AA, has been discontinued and replaced by a metal arm, Mopar 68078306AA, which is what I've purchased. However, the new arm won't fit over the old knurled piece on the motor shaft. The old piece is about 1/4" deep and has straight sides. However, it looks like the new arm needs a shallower tapered piece that it snugs into.

Has anyone replaced the old arm with the new one and can fill me in on what the trick is to make it fit? Do I need to replace the whole motor to get the proper shaft configuration?

Thanks for your help.

Ken

 

Just thinking of your knurled connection. I don't know what your drive looks like but from previous car I have worked on the knurled fitting sometimes comes off leaving the drive shaft with flats on it to fit inside the knurled fitting.