Had stuck wiper arms tip on removal. I sprayed penetrant and let it do what it could, that got the locks free. Next small block of wood 1" thick 6" long to get a soft base to rest screwdriver on. Gently pry the outer edge of the arm where it mounts on the wiper post. That helped a great deal.

Next, replacing the bushings, to get rid of the slop and noise. Both Advance and The Zone sell a universal bushing kit. One bushing does not fit properly so I cut the tip off and presto. Ive done it on both trucks and its made a world of diff., got rid of the noise and also the jerks that happen from worn out bushings.
Final tip, when you drive down the road at 55 to 65 and hear a slight clunk thats, its because the clips on the cowl cover didn't go all the way in, or in my case one of them, felt like daaaa

 

The noise you are referring to is? My truck makes a whining while the wipers are on, is that what you are referring to?

 

and don't use heat...the plastic could light up in flames as it did for me...

 

LOL Shadow thats why I made the post, I could just see flamin wipers, rofl

 

YEs, I thought it was motor but once I rebushed the 89 the noise was gone, so I did the 94 and presto! Only wiper noise I hear now is normal motor sound, no whirr.