Cutting and Turning
Cutting and turning is probably
the most difficult and most “feared” aspect of a spring over. But
in reality, if done correctly, it is not that hard at all,
and I believe any rig lifted over 5” should have it done, regardless of
whether it is sprung over or under. It provides such a big advantage,
especially in the case of a spring over, and since you are already there
so you might as well do it right the first time.
If you think that you are
not up for the task of cutting and turning, several companies cut and turn
axles for people, including Cruiser
Outfitters and Proffitt's
Cruiser's. Proffitt's even offers a SOA kit. It is usually
about $150-$200 to buy a cut and turned axle + core charge.
**If you are thinking of
doing a Shackle reversal (see page 7
later in the article to read about them), do the shackle reversal BEFORE
you take measurements for your cut and turn.
A good, unofficial description
of cutting and turning is basically: "a way to correct your steering on
your front axle because you are rotating your pinion up toward your transfer
Because you are lifting your
rig so much, it will create fairly "extreme" front axle angles if you do
not cut and turn. Here is a photo of an axle before cutting and turning
- you will see the front pinion output is level - exiting at 90 degrees.
Because you are lifting the rig so high, you want to rotate the pinion
up, out of the way of rocks, and up, towards to the transfer case front
output, to get a better u-joint angle. Otherwise it can bind and
cause something to break.
A front axle, sprung over,
before cutting and turning, with the weight of the
vehicle sitting on the front
axle using jack stands:
First, take your measurements:
First, you want to take
your measurements of where you want your axle to point. Before you
weld on the front perches, you want to place the weight of the vehicle
on the front axle as seen in the photo above with u-bolts bolted up loosely,
mostly for safety. Then, using a floor jack, push the pinion up so
that it points at your transfer case output. Use an angle finder
to figure out how many degrees of difference you have changed it.
It does not matter where you take your angle, as long as you use the same
place for all measurements:
(Photo taken by Tien Do)
For Steering and Caster
The OEM caster (steering)
degree point are a good place to start and reference as "zero," whether
the angle finder reads that or not. Ideally, especially when going
to larger tires, you want to increase your steering arm angle (move the
end of the arm higher than it was before) about 4-6 degrees. This
makes steering easier and creates less wandering. Therefore, you
will need to add about 4-6 degrees to whatever your pinion angle is rotated
at. For example, if you rotate 14 degree up for pinion angle, you
will need to add another 4 degree so your total rotation will be 18-20
degrees. When you do the actual rotation this will all make sense....
C&T in a vise or
on the rig?
Cutting and turning can
be done in a vise or in a jig, or it can be done by simply bolting your
whole axle to the front springs tightly, and doing it while on the truck.
To cut and turn, first break
down the knuckles to their bare housings. When you rebuild it, you
should replace the seals and bearings while you are in there. You
want to break them down because it’s easier to “turn” the knuckles when
they are bare (those two large holes), and because of the heat your axle
will experience when being welded back up could potentially melt your inner
axle seal and cause it to leak, which will force you to have to tear it
down again later.
Next, cut the axle just a
hair inside of the OEM weld:
You want to cut about 1/4"
wide and you should visibly see the line between the outer and inner axle
sleeves. In the photo above, the inner sleeve is red, while the outer
is black. Do not cut too deep, the outer sleeve is exactly 6mm wide.
The trick is to cut consistently 1/4" (6mm) deep completely around the
outer perimeter which is why a pipe cutter does such a good job cutting
and turning. (actual cutaway photo courtesy Jack Rice)
Here is an example of good
leverage to turn the housing. Because a new front axle rebuilt kit
is recommended (and most come with new trunion/steering bearings), simply
use your old bearing races to protect the housing from damage while using
the pipe to turn.
Here you can see the bearing
races, kept in place to turn the housing. You can also see where
the axle was cut and turned:
Once down to the bare housing,
you can use a variety of devices to “cut.” The most popular one is
a large pipe cutter, but you have to grind down the old welds and bump
stops before you can use it. It does make the nicest and cleanest
cut, though. You can also use an angle grinder with a cutoff wheel,
and simply widen the cut later with a grinding wheel.
Another example of a good
cut with an angle grinder:
(Photo by Cruiser Ken)
You want to go about a hair
or two deeper than 1/4” because that is the thickness of the outer axle.
The knuckle housing is sleeved into the axle, so there is an inner and
outer layer, with the only thing keeping them together being the visible
OEM weld at the end of the housing.
Then weld it all up, bolt
it back under the truck, and put the axle back together!
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