| Saturday, April 2nd, I was milling around the junkyard looking for a
dipstick and tube for the 350 and happened across a stripped half ton
Chevy 10 van. There was no engine to salvage a dipstick from; in
fact the only thing left was a side shifted transmission and it looked
real familiar except for one thing. The shift levers were quite
different from those on my Saginaw 4 speed. Because the the
levers were actuated by long shift rods that had to be routed around the
engine (a three on the tree setup), they were stouter and set off to the side of the transmission.
An oblique view showing the levers can be seen
HERE. I
purchased the levers and installed
them on the converted and now recently painted green four speed.
However, after thinking about the pros and cons
of keeping the four speed I returned the next day to pull the entire 3
speed and gamble that the conversion kit would fit. The Saginaw
four speed would have been a fine transmission to use except for the
fact that I was unable to devise an easy way to get connect the shifters
3 linkages. The only easy way would have been to cut a large hole
in the floor of the drivers floor and that looked pretty if-y. |
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| I opened the 3 speed before I took it
out of the yard. All the teeth look fine and the synchronizer
rings were in good shape too. It wasn't practical to take the
whole thing apart to look at every thing so I purchased it as is for
$86.02. Turns out that the part of the input shaft that slides
into the pilot bearing was a little rusty, the
needle bearings between
the input and output shafts were shot, as well as the rear clutch ring
and the reverse gear. Luckily for me all of these parts are interchangeable with
the four speed parts except for the bad 3 speed reverse gear which I
found a used
replacement from Napa for $45. |
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| Once the side cover is off, the tail shaft housing will pull out just enough to expose this snap ring.
Remove the tail shaft by squeezing the tabs together with a pair of needle nose
pliers while
pulling the tail shaft off the bearing. |
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| Condition of the original output shaft doesn't matter as it will be
discarded. You will likely find that the shaft is stuck in this
position and will not pull out farther. To remove the shaft
completely, slide the rear clutch ring into the first gear position and
use a standard screwdriver to remove the
E-clip that holds the reverse idler gear in place.
After the E-clip is removed the gears can be moved back and fourth
providing just enough room to remove the output shaft as an assembly. |
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| Since the 4wd conversion kit has already been installed in the four
speed, I had to remove the kit from the four speed before installing it into the
new three speed. The clutch hubs are the tightest fitting parts on the
shaft, so removal may sometimes prove difficult. Don't forget to
remove the snap rings first! The front clutch hub came off easily enough by pounding the
shaft on a piece of wood (the clutch hub's own inertia acts to remove
it). The conversion shaft was
removed from the twin bearings in the adapter by hitting the end of
it with a shot filled mallet. The rear clutch hub however was a
different story. A hammer and brass drift were not sufficient to
remove, so it had to be pressed off. |
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| Despite being removed fairly easily, the front clutch hub had to be
pressed back on. After that,
reassembly of the conversion shaft with the 3 speed gear set was a
simple matter of sliding everything back in the correct order. |
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| Use the shot-filled mallet to install the conversion shaft into the
forward bearing in the adapter plate. A
spacer is inserted between the two
bearings. Once the spacer is in, the optional second bearing can
be installed followed by the D-20's
input gear, washer, and nut. |
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| This whole assembly can now be wiggled into the case. The gears will have to be finessed around
the reverse idler gear just as was done during disassembly, but with the
added difficulty of having to insert the front of the output shaft into
the rear of the input shaft without knocking the needle bearings out of
position in
the rear of the input shaft.
Use small pieces of tape to hold the gasket in place as it is very loose
on the adapter. |
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| Once the adapter is bolted up, and you're satisfied that everything
is in its proper place, the input shaft bearing can be inserted (easier
if snap ring is already installed on outside of bearing).
Next replace the smaller snap ring on the input shaft and cover it
with the bearing retainer. The completed assembly at right. |
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| Mounting the Saginaw required a little modification to the stock
cross member. Specifically I ground off one of the original T-90
mounting brackets and drilled a couple of holes to bolt the adapter to
the cross member. Saginaw mounted and painted at right. |
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