RE: swapping tapered axles for later flanged axles
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

RE: swapping tapered axles for later flanged axles

Nick, The following is a section from a Mopar 8 ¾ rear end guide that explains why you had to shorten the axles on your 63 Fury.


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", it’s the block that both left and right axles butt up against inside the center of the differential. Prior to 1964, all open differentials used a thrust block 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 be produced 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 rear ends and axles originally equipped with an open differential. The original axles must be machined or original Sure Grip length axles must be used.






From: 1962to1965mopars@xxxxxxxxxxxxxxxx [mailto:1962to1965mopars@xxxxxxxxxxxxxxxx] On Behalf Of furyus63@xxxxxxxxxxx
Sent: Thursday, May 7, 2015 10:06 PM
To: 1962to1965mopars
Subject: Re: swapping tapered axles for later flanged axles


On my '63 Fury when changing my 741/2.76 Non-Sure Grip for a 742/3.55 Sure Grip unit I found that I had to shorten my axles 1/16" to fit the SG unit. I figured this would be the time to swap to the flanged axles. I was not able to find any information about this swap. I changed over the swedged hubs, shortened the axles and has been good for ten years far. Our '63 housings drum to drum are 58 1/2" which allows us big tires. The '66 units are 59 1/2" and are a good replacement as Herb said. If you have the funds, or as racers often do, build a unit with custom length axles.


I run 285/70R15 tires on 15x7 wheels with 4 5/8" BS. I ran the same big wheel tire size on my '63 SF.



Nick T. 



Please address private email -- email of interest to only one person -- directly to that person. That is, email your parts/car transactions and negotiations, as well as other personal messages, only to the intended recipient. Do not just press "reply" and send your email to everyone using the general '62-'65 Clubhouse public email address. This practice will protect your privacy, reduce the total volume of mail and fine-tune the content signal to Mopar topic. Thanks!
1962 to 1965 Mopar Clubhouse Discussion Guidelines: and
You received this message because you are subscribed to the Google Groups "The 1962 to 1965 Mopar Mail List Clubhouse" group.

You received this message because you are subscribed to the Google Groups "The 1962 to 1965 Mopar Mail List Clubhouse" group.
To unsubscribe from this group and stop receiving emails from it, send an email to 1962to1965mopars+unsubscribe@xxxxxxxxxxxxxxxx.
For more options, visit

Home Back to the Home of the Forward Look Network