> Date: Sun, 29 Aug 2004 10:57:53 -0400
> From: "William Schickling" <wschick1@twcny.rr.com>
> Subject: [oletrucks] More help needed
>
> List,
>
> I am progressing well on my rebuild. This weekend I got my engine, bell
> housing, flywheel, clutch, and T-5 transmission installed in the frame of my
> 1940 1/2 ton. I need a little help with getting a driveshaft. The space
> between the center points of where the universal joints would be is 46 and
> 7/8 inches. That is with the yoke pushed all the way into the tail shaft. I
> assume the slip fit of the yoke is the point that allows the drive train to
> compensate for movement of the rear end, however I don't know how much to
> subtract when calculating the length for the driveshaft. Also I have no idea
> what I need for yokes at the ends of the drive shaft. As I said the
> transmission is a T-5. The rear end is a 1955 1st series. Do I need to match
> up the yokes? I have heard that NAPA, I assume others do as well, sells a
> double size universal joint to connect mis-matched ends. Does anyone know
> what universal joints go with the T-5 or the 1955 1st series rear end?
>
The T5 slide in yoke should be the same as the fine spline
yoke that was used on many GM transmission from the the 60s
to the 90s. There were some different designs of this yoke
over the years, using two different styles of ujoints, and
with differences in design so that some are stronger than
others, and some are longer than others by perhaps half an
inch. If you have a yoke that has snap ring grooves in the
holes where the ujoint caps fit in, then it should use the
same ujoint as the 55 truck rearend uses (perfect circle #
153). If you have a yoke that does not have the grooves,
then you would need the conversion ujoint, PC # 3022, which
costs more and is harder to find.
The driveshaft shop can handle the situation in different
ways, depending on what parts you have to offer and what
they have laying around. I usually try to find a shaft with
the correct ends on it, that only needs to be shortened to
work in what I'm building. I'd recommend using the 153
style ujoints and tranny yoke, then you will have a
driveshaft that is easy to find parts for.
I generally put the yoke into the tranny all the way, then
pull it out about 3/4 to one inch, and measure the length of
the required driveshaft (center-center distance between the
tranny ujoint and the rearend ujoint). But this assumes the
truck is sitting in it's "normal" ride height, ie. the cab
and bed and other heavy things are installed on the frame.
If you are just working on the bare chassis, it might be
worth waiting till you get some weight on it to measure the
driveshaft length.
--
Jim
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