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Project CJ-7 ~ Scout II
Dana 44 Axles Swap onto a CJ-7 Frame
Castor Adjustment
Options
This
option will not correct ZERO degree castor but will help
fine tune castor and correct minor Camber problems as well.
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With the swap of a set of 1976 Scout II Dana 44 axles, the
front axle's knuckles had a castor of 0° from factory.
The CJ-7 axles had a castor of 4° to 5° of positive castor
(meaning the wheels tilted rearward by 4-5°). Only the
last year of the Scout did IH put any castor (2°) in it's
front axles and I wasn't lucky enough to find a set from that
year. What castor does for the front axle is help it
self- center which basically means it will naturally lean
towards pointing straight ahead while turning. Without
any castor (0°) the steering would have a tendency to wander
even when pointing straight ahead and would not move towards
center while exiting a turn. |
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There are a few solutions to zero degrees of castor. First is to shim
the axle on the leaf springs causing the axle to lean rearward. A
side-effect of shims is that this also causes the pinion to point towards the
ground. The Dana 44 front axle's pinion from the Scout already points
slightly towards the ground so causing it to point further to the ground is not
a desirable thing. For one the drive shaft will be put on a harder angle and
two, pointing it towards the ground puts it further in harm's way while on the
trail. Because the spring pad on the passenger side of the Scout's Dana 44
front axle is part of the housing, you can't cut off the spring pads and rotate
just the pads as in some wider front solid axles. Another option is to rotate the inner knuckles rearward by
the desired amount of castor. This is not as easy as it
sounds. The inner knuckle is welded to the axle tube so
the weld needs to be ground off carefully and the knuckle has
to either be pressed off hydraulically or whacked off with a
hammer after the weld has been removed. Then the
knuckles need to be rotated evenly by the desired amount of
castor and re-welded. This is the best solution to the
castor problem but not the easiest to requiring some knowledge
of measuring castor and welding. Ultimately, this is the
option I will have to do for the Scout Axle. The castor
correctors here will help fine tune the castor and help adjust
the camber if needed.
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Another solution I found to gain some castor in the front
Dana 44 axle also happens to be the easiest to do. I
found something called Castor
Correctors though a company called "The
Scout Ranch" which require no serious modifications and can be
re-adjusted or even removed if need be. What the Castor
Correctors do is replace the upper ball joint guide that
screws down into the knuckle with one that looks the same on
the outside but has an angled hole on the inside (See
illustration A1). Using the Castor Correctors tilts the upper ball
joint up to 1.5 degrees in the desired direction and can be
used to make small corrections to castor down to 1/8th
degree. |
A1 - Guide on left
is stock. Guide on right is a Castor Corrector.
Notice the off center hole.
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Installation of Castor Correctors was not
difficult although a few things should be taken into
consideration. First thing to consider is that if
your upper and lower ball joints are old, now is the time to
replace them. The
Scout Ranch can supply a tool for removing the ball joint guide however the
tool (or any tool for that matter) can not handle the torque
it required to back out the guide off of the upper ball joint
without taking the tension off the guide. Possibly some
axles do not have the tension that my Dana 44 had but if they
did not have that tension, then there could be some possible
wear associated with the guide or ball joint stud. The
Guide that you will remove has a slot in it allowing it to
expand in the threads of the knuckle locking it in
place. In order to remove the tension, you have to
remove the bolt off of the upper ball joint. Under that
bolt is where the ball joint guide is. I decided to
replace both the upper and lower ball joints at this time so
installation of the Castor Correctors was just as easy as
putting the stock guide back on. At the bottom of this
page is some tips on replacing the upper and lower ball
joints. If you are planning to reuse your ball joints I
think that the easiest way to take the tension off of the
guide is to loosen the lower ball joint nut (if you can get to
it), and then remove the upper ball joint nut. Use a
ball joint tool to press down on the upper ball joint.
it probably won't pop out easy so a few good whacks with a
hammer onto the out steering knuckle should persuade it to
back out just enough to take the tension off the upper ball
joint guide. Once the tension is off the guide, you can
use the tool to back out the guide and replace it with the new
Castor Corrector. Next, tighten up your lower ball
joints again. Next you will insert the Castor
Correctors. The Castor Correctors, when being
turned in,
will appear to wobble the upper ball joint and outer steering
knuckle. This is how you will adjust your castor.
Here's another thing to remember so pay attention and you
won't make the same mistake I did. When turning in your Castor Correctors
keep in mind that you want the ball joint stud to lean forward
when looking at the top. This will cause the bottom of
the ball joint stud to be as rearward as possible. You
can gage it by the slot in the Castor Corrector which should
be towards the rear of the vehicle. This gives you
castor is the proper direction if your application is the same
as mine. Now here is the thing. While turning in
your Castor Correctors turn it in until you feel it get tight
BUT DO NOT TIGHTEN IT. If you can not turn the slot
easily to the rear most part of the knuckle's threads, you
should back up to the last time around. You may think
that you'll be able to turn it in far enough to get the slot
around again to lean the stud but it gets tight quick and if
you don't make it around to where you want the Castor
Corrector to stop you'll have to go though the whole process
again. The tool can not back out an over tightened
Castor Corrector. Don't try too hard if you tighten it
too much or you ruin the tool. You'll have to loosen the
lower ball joint again and use a ball joint remover tool to
press it down in order to be able to back out the Castor
Corrector. TRUST ME. I been there, done that. |
Once you have the Castor Corrector in place, put the
shimmed washer on the ball joint stud. This shim is to
give the bolt a flat place to seat. So depending on your
degree of needed castor you will put the shimmed washer so
that thinner side is towards the side that the stud is
leaning, opposite the slot in the Castor Corrector. All
that is left is to tighten down on the ball joint bolt to the
desired torque specs and put the cotter pin in. You may
have to hold the shimmed washer as you tighten the ball joint
nut or it may spin. I had to try a few times.
Overall that's it. It's not as hard as it sounds.
It only took a few hours and that included replacing the ball
joints and having to remove the tension twice on one
side but you won't have to worry about that, right? |
Upper and Lower Ball Joint ReplacementTo replace the ball joints I disassembled the hubs, removed the bearings and
the axles from the housing. With a clear view of the ball joints I removed
the nuts and used a ball joint remover to press out the lower ball joint from
the inner knuckle. The trick here was to put as much pressure on the lower
ball joint and then give the upper ball joint stud a whack with a hammer.
Both ball joint studs popped out. Then removal of the upper ball joint
stud guide was easy using the tool acquired from The
Scout Ranch.
Next step for my process was to replace the ball joints.
After removing the snap rings, I used a hammer to whack out the ball joints from
below the knuckle. For the upper ball joint I used a metal shaft and ran
it though the lower ball joint hole (after removing the lower ball joint).
I wrapped a rag around the shaft where it ran though the hole to protect it from
damage while hammering away at the upper ball joint. I then used a
bench vise and various pieces of metal to press the new ball joints into the
outer knuckle.
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