Vote for The Forward Look Network on the Mopar Top 100 Sites 

Excerpt from

From: Daven Anderson
Remote Name:
Date: February 04, 2003
Time: 13:42:27

Comments A Chrysler 8-3/4" Rear Axle Guide, Part II Section 1: Thrust Block Variations: There was a difference in thrust blocks prior to 1964 that make center section interchange, as well as axle interchange problematic. The thrust block, or "axle shaft thrust spacer", in that both left and right axles butt up against inside the center of thedifferential. Prior to 1964, all open differentials used a thrustblock was approximately 1/8" to 1/4" thicker than units made after 1964. The Sure Grip thrust block prior to 1964, however, was indentical to all 1964 and later Sure Grips and open differentials.In 1964, the thrust block width was changed to match the Sure Grip thrust block width. This difference in thrust blocks between Sure Grip differentials and open differentials required that two different axles beproduced for each 8-3/4" housing manufactured. This is true of all 1959-1963 cars with 8-3/4"s. A 1964 and later differential, or any Sure Grip differential, cannot be used with 1959-1963 rearends and axles originally equipped with an open differential. The original axles must be machined or original Sure Grip length axles must be used. Part II, Section 3 contains housing and axle sizes and part numbers for these early 8-3/4" rearends.


Last changed: July 19, 2018