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[oletrucks] RE:Changing the differential

To: "Oletruck list" <oletrucks@autox.team.net>
Subject: [oletrucks] RE:Changing the differential
From: "Gwyn Reedy" <mgr@mgrcorp.com>
Date: Tue, 4 Jan 2000 20:31:07 -0500
It should work if:
1) you are correct that the later pumpkin will directly bolt into the older
housing.
2) the shortened axles will work right in the wheel bearing area. Do the
rear ends use the same type of wheel bearing? Axle shafts same diameter?

Sounds like a clever plan. Please try it and let us know!!

Gwyn Reedy
Brandon, Florida
mailto:mgr@mgrcorp.com
'72 Cheyenne half ton (driver)
'69 El Camino SS396 (rebuilder)


>
> Here is a "Proposed Solution" to the dilemma.  I need "CONFIRMATION" or
> "MYTH DESTRUCTION" here listmembers.  Little help, PLEASE?
>
>   The TF series "Corporate 3/4 & 1-ton differential units have a smooth
> round 10-bolt inspection cover.  I've been told that the
> differential itself
> is called a 10-1/4" drop out unit, getting it's name from the diameter of
> the ring gear.  The "drop-out" unbolts and is removed from the
> front of the
> rear axle housing (and\or the rear of the front axle housing on my 4x4).
> The axles are 17 spline axles, and the model number for the GM Corporate
> axle is HO-72.
>
>   A later model corporate 3/4 and 1-ton differential drop out unit,
> manufactured from the early 60's through the early 70's will directly bolt
> in to the early style TF axle housing, but is designed for 30
> spline axles.
> The matching 30 spline axles from the same series differentials can be cut
> down 1/2 inch at the differential end, which then becomes a direct bolt up
> into our older housings.
>
>   Possible benefits of this swap include a stronger axle (30 vs
> 17 spline),
> and the instant on the shelf, or in the junkyard availability of
> myriad ring
> and pinion combinations, including posi-traction units.  In addition, the
> drop out assembly should have the backlash correctly set already,
> or can be
> set for a reasonable price by a rear end shop as it's already out of the
> truck.  It then becomes an "owner can do" project, with the only really
> technical portion being proper torque specs on the install.
>
>   I did ask an axle manufacturer about the strength portion, and he says
> that it's very true.  30 "is" stronger than 17.
>
>   If this scenario is in fact true, then junkyards had better stand by for
> the crowds!  What do you say "oletruckers"???
>
> Kevin P.
> '59 Apache 38/NAPCO
>
>
> oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
>

oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959

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