Greaseable rear shackles
 

Instead of buying new rear shackles with rubber bushings for my 87 3/4 ton 4x4 GMC I purchased poly bushings from Energy Suspension (Part Number: 3.2126, Eye Bushings 1-3/8 Inch Eye, Price: $13.99 for 1 set of 4). After pressing out the original bushings (which are molded into the shackle) I drilled and tapped them for a grease Zerk (1/4-28). I then painted the parts black and installed the Zerk's with a stainless steel washer under the Zerk head so the Zerk would not protrude into the ID of the bushing bore. I used blue loctite on the Zerk threads.
I also drilled a hole into the bushing tube but is not really needed as I want the poly bushings to slide in the bore of the shackle and not around the mounting bolt. I tightened the mounting bolt nut so the center tube is in compression and will not turn. The shackle rotates on the OD of the bushings. They work really good.

Re: Greaseable rear shackles
 

nice mod