Reply to "1/2 Shaft"

Original half shafts have noticeably larger yokes than spicers. With a little help from the Board, someone not familiar with each could measure the distance acrossed each to determine which one they had.

As far as which are better, I had a conversation with Dennis Quella at Pantera Performance a few years ago on the subject. Besides the normal Pantera work over the last several decades, he also has prepped ZFs for the hill climb guys in CO.

At that time, he indicated the primary reason for popularity of after market shafts was the poor availability and quality of OE u-joints. The CO uphill guys have used Pantera shafts without problems. -Very harsh high pony, impulse loading service. Dennis also said that he had seen stock u-joints themselves fracture and attributed it to the u-joint being larger in span, but not typically as beefy as Spicers, and also weekened by the location of the greases zerk holes.

The splines on poorly maintained half shafts and also ones that have seen a lot of hole shots with big tires and built engines tend to suffer a lot of slop and/or not slide freely.

Spicers are very comparable to mid-year Vette half shafts in size, but Vette shafts are fixed length. The week spot in Vette rear ends was third member casting, not the haft shafts themselves, although it was not unheard of for big block cars to shear the four high grade bolts at the wheel carrier or snap a u-bolt at the third member yoke (been there-done that).