Specifications:

Cap diameter:  1.188"

Snap ring to snap ring groove:  3.625"

Greaseable:  No

Dana life series 1350 u-joint.  This u-joint does NOT have a grease zerk.  Since there's no adding grease, the cross is solid instead of hollow (for grease passages to each cap), and being solid increases strength over greaseable u-joints. The journal crosses are cold-formed from high quality steel, and ample grease reservoirs in each trunnion assure effective lubrication. They come pre-filled with high quality synthetic grease, and use Spicer's highest quality triple-lip seal to keep out the elements.  It comes with 3 sets of 4 external clips (total of 12) to fit various set ups.  Be sure to measure your old clips and install new ones of the same thickness!

People think greaseable u-joints are better because they can be greased; pushing out contaminates, and fresh grease in.  That's old school thinking.  A greaseable u-joint's seals allow for air and grease to escape (i.e. not a perfect seal).  If the seal was good, then they would prevent the new grease from going in because the old grease, water, dirt, etc. couldn't get out.  Anyone who's greased a u-joint knows if you put too much grease in, it pushes out of the seals.

Life series u-joints have a nearly perfect seal.  This seal prevents contaminants from entering, and the grease that comes preinstalled from leaving.  Nothing gets in, nothing gets out, so there's no need to push out contaminants.  I became a believer when my driveline lasted 295,000 miles before the u-joint went bad!  The solid cross makes them stronger, so they can take a harder hit than the greaseable, AND the better sealing keeps out contaminates, so they last longer than the greaseable.  They're better in every way.

WARNING: Do not add grease or switch the caps! Each unit, and each cap on each unit, has been exactingly greased at the factory. Additional grease, or just swapping cap to cap, can reduce the life expectancy. A simple symbol on the cap that matches the corresponding location on the cross can assure that the right cap gets back to its home during assembly.