How to Swap a Solid Front Axle
into a First Generation S-10
First off, I want to present this in as simple as a
manner as I can. If a project of this magnitude scares you, I want to get rid of
those fears. My swap took just over a year to complete. Planning, parts
gathering, and more planning consumed 90% of my time. Did I mention planning?
Patience is key here, so make sure you have lots of it. With that said, let's
The S-10 comes from the factory with an independent front suspension (IFS)
manufactured by American Axle Manufacturing. No years of production ever offered
a solid axle, although we all wish they did! This configuration is prone to
accelerated wear and breakage when used off-highway. CV axles, ball joints, and
idler arms are the most frequently replaced components. The rear suspension is a
leaf sprung solid axle, with the axle residing on top of the springs. The GM
10-Bolt in the S-10's comes with either a 7.5" ring gear and 26 spline axle
shafts, or a 7.625" ring gear and 28 spline axle shafts. This axle is comparable
to the Dana 35 / 35c and 8.25 Chrysler Corporate unit.
II. Preliminary Planning
When you decide to start cranking the SFA gears, there are a few things that you
need to decide before you start. The first is the obvious "Leaves vs. Coils"
debate. While coils will yield lots of articulation, keep in mind that coil
suspensions are much more complicated than leaf springs and have more
axle-to-frame linkages. Also keep in mind the sometimes common "death-wobble"
associated with coil sprung Jeep Cherokees, or "torque-steer" in Jeep TJ's.
After you decide the type of suspension, now the gears shift into how much lift
you want. Leaf springers need to ask if they want spring over or under, flat
springs or arched springs, etc etc. Coil springers will need to figure out how
long control arms need to be and what coils to use (progressive rate or
standard). Each decision you make at this stage can put you anywhere on the map,
so give these serious thought.
III. Searching for Parts
This is another stage where good planning comes into play. Be honest when
assessing your needs at this stage, as it will save you from headache later and
keep some of your wallet intact. When searching for a front axle, you want to
find something with the differential on the left-hand side, otherwise your
transfer case wont match up (assuming you have the stock NP 231.) Try to get the
tie-rod and draglink with it as well.
If you use a Reverse Cut Dana 30 from an '87 - '95 Jeep Wrangler, it makes life
a lot easier. For instance, the pinion yoke and transfer case yokes are the
same, brake lines adapt without hitch, and best of all, steering is a direct
bolt on. Any Jeep Wrangler pitman arm will bolt on to the S-10's Saginaw
steering box. Spring perches are also at a perfect distance apart, at 31". This
allows the springs to sit inside of the frame rails just as the stage west kit
was designed, while spring perches do not require modification. This unit is
very adaptable, and can survive 35" tires without a hitch. The Dana 44 is also a
great choice for an axle. Almost all of the parts are available at Pep Boys,
Auto Zone, Advance Auto, etc. These axles can be built from mild to wild or
anything in between. Best picks to swap into an S-10 would be from '66 - '77
Ford Broncos and late '70s and early '80's Wagoneers. Note that when swapping
the Wagoneer axle, it has a 6-lug pattern that must be either converted to match
the rear, or the rear must have the same lug pattern. Bronco axles will have the
5 on 5.5" lug pattern, making adaptation quite easy to other axles. Some came
with the Spicer 1310 series pinion yoke, while others may have had the Spicer
1330. The Dana 60 is the obvious choice for ultimate strength. Used in many
applications over the years, unfortunately none came in an appropriate width for
the S-10. If you did want to go full width, take into consideration that your
tires will not be under any part of the vehicle. This is illegal in some states,
so make sure you know the details before making a purchase. The Dana 60 is an
8-lug axle that came on just about any 1-ton pickup. Ford Dana 60's have the
driver's side drop required by the S-10. Like the Dana 44, many axle-shaft,
u-joint and ring and pinion upgrades are available. Any axle listed here would
be a good choice, yet if cost is a limiting factor, the Dana 30 alone is a great
axle. Of course the hardcore guys will tell ya it is a weak axle, it really is
appropriate to the size and weight of the S-10. So unless you are into some
hardcore rock crawling, the Dana 30 or 44 will prove to be a great bang for the
B. Rear Axles
GM 10-Bolt, Dana 35 / 35C, and some Chrysler Corporate axles all share the same
relative strength. They are considered "safe" up to 33" tires, but after that,
look out. Axle shafts will snap, axle tubes will spin, and wheel bearings will
be eaten up. They are adequate for one who goes off-roading on occasion, or
those with medium to mild trail tastes.
GM 12 Bolts Ford 9"s, and Dana 44's are and awesome compromise between strength
and expense of parts and ground clearance. Availability of parts its great,
where you can get bearings seals, etc at almost any parts store, and gear/locker
choices are innumerable while still not totally breaking the bank. Ford 9" and
Dana 44's are available in appropriate widths, coming from '66 - '77 Broncos, or
late model International Harvester Scouts. The 12-Bolt was most common in
trucks, so finding one in the right width may be tricky. GM 14-Bolts, Dana 60's,
70's, 80's, and Rockwell 2.5's are all you need to know for ultimate strength.
These axles were used in 1-ton pickups, Ford F-250's and up, M1009's and M715's
and other military vehicles came with these axles. 14-Bolts are the most common
wrecking yard find, with prices ranging from 75 to 200 dollars. Military
14-Bolts came stock with Detroit Lockers and more acceptable gear ratios.
Dana 60's are another common find, but hope that no one has taken out the good
stuff. A Dana 60 in good condition should run about 200-300 dollars. 70's, 80's
and Rockwells come in UPS trucks, Step Vans, U haul trucks, F-450's, 550's,
650's and 750's.
Many people have used all kinds of springs for their projects. The most popular
choices are springs from Wranglers, CJ's, full-size vans, Dodge Dakotas, and
S-10's. In my own project, I used Dakota springs, with a CJ add-a-leaf. In the
near future, I plan on adding another main leaf from some Dodge Dakota springs.
D. Steel / Misc.
When fabricating my mounts for springs, I used 3/16ths Box tubing for my cross
member and other brackets. You can use 1/4", but in my opinion, i would rather
save weight and use the 3/16ths. It is strong enough to carry the weight of the
vehicle, while not burdening the rest of the vehicle with excess weight. When
designing a leaf spring suspension for an S-10, the trend is to make a cross
member with a drop to it that is welded to the bottom of the frame in the front.
The Stage West kit is designed like this. Especially important in the front, to
prevent unnecessary negative arch to the springs, is to have the straight line
connecting the endpoints of the spring to be almost if not exactly parallel to
the ground plane. If you look at the Stage West kit, the drop bracket and where
the end of the shackle is, is a parallel line.
IV. Pre-Swap Fabrication
Before you swap, it is important to know that you can weld on cross members and
test fit springs before chopping any bit of IFS off. Also, be sure to drill a
3/4 " dia. Hole through the frame exactly 3 inches back from the original hole
that Stage West used for mounting the shackle bolts. Be sure to sleeve this hole
with some .75" tubing. If you plan on doing a Stage West style swap, note that
Dakota springs are the closest match to the springs that they supply with the
now-discontinued kit. When fabricating your cross member, assuming that you have
leaf springs, make sure that you are absolutely sure of your welding skills. If
not, have someone else do it. Remember, the weight of your front end will be on
these springs, so you don't want any shoddy welds breaking in the
V. IFS Removal
This can be taken care of with an acetylene torch, plasma cutter, or in its
simplest form, unbolting as much as you can, then using a 4.5" angle grinder and
a cutoff wheel to eliminate any offending IFS brackets. Retain the shock mounts
as they can be used with relative ease on the new axle. Take extra care not to
knick the brake lines (rubber or steel) and make sure to disconnect every
connection to the center section before letting it drop. This includes breather
hoses, electrical connections, CAD cables, drive shaft, etc. This is the most
time consuming process in the whole swap, taking up 1- 3 "average persons" days.
My swap took about a week and a half working at a leisurely pace after work in
the weekday, and all day on Saturdays and Sundays.
VI. Assembly (Front)
By this time I am assuming that you have checked and double-checked you
measurements of your cross member and shackle boltholes. In my situation, I had
a cart that you move furniture with. It's about 3 inches off the ground, has
some heavy-duty casters on it, and has a wooden deck on it. I bolted the springs
to the axle, along with all of the steering components, and placed it on the
cart. From there, I just wheeled it under the vehicle and bolted the front of
the springs on first (the end that doesn't have the shackle.) Next, attach the
steering, brakes, and electrical connections (4wd light switch). Do the drive
shafts last, since this requires the skills of a driveline shop.
VII. Assembly (Rear)
The rear is fairly straightforward and doesn't require that much thought.
Basically, it involves removing the old axle, retaining the old hard brake
lines, and preparing the drive shaft for adapting with Neapco PN 3-3130. After
removal of the axle, attach the springs to the shackles, wheel the new axle
under and set the spring pads onto the axle. Now set the pinion angle, making
sure that the angles at the transfer case and at the pinion cancel each other
out. This will eliminate any driveline vibrations. In my case with a simple
spring over in the rear, I didn't need a new drive shaft. It's a little short,
but it still has enough room to do its job. When welding spring perches, make
sure you only do about 1" at a time on opposite corners of the spring perch.
This will reduce warping created by the welding process. Be sure not to
test-drive the vehicle with just tack welds on the spring perches. I made that
mistake and caught myself just before I drove off. As soon as I put it in drive,
the initial lurch of the vehicle snapped the welds and sent the pinion vertical,
almost destroying the U-joint and pulling the drive shaft out of the transfer
case. Emergency brakes aren't tough, but do require probably the most effort,
due to adapting cables and getting them to hold just right. In my project, I
took out the E-brake stuff, and will install a line lock soon.
VIII. Test Drive Preparation
Before getting all antsy and wanting to drive it around the block or over your
neighbors landscape, make sure that you will be safe when you ride in it. Here
is a checklist:
- Are the tires inflated to recommended pressure?
- Are the brakes bled thoroughly?
- Do the tires have adequate clearance?
- Does the steering move freely?
- Is the drive shaft secured to the transfer case and
- Are all suspension bolts / nuts and lug nuts properly
- Are the axles filled with the appropriate amount of
- Have the wheel bearings been packed with grease?
This is just a basic checklist, and there are probably
more things to look over. Remember, it is the owner/operator's responsibility to
make sure that the vehicle is safe to drive.
IX. Test Drive
On the initial test drive, I recommend taking the vehicle for a short test drive
in your neighborhood, away from heavy traffic, and not to stray too far incase
you need to be towed back home. Take careful note of the handling
characteristics, braking distances, whether or not you have bad axle wrap under
acceleration, etc, etc. Fix each problem, and then take it out for another test
drive. By doing this, you will keep
uncovering problems until you are ready to take it off road. Remember that when
you have a lifted truck, your center of gravity will be raised, your braking
distance will be increased, requiring a more alert driver. Be sure to adjust
your driving style accordingly.
X. Final Thoughts
This project is easy to do unless you psyche yourself into it being a difficult
one. Here are three pieces of advice I would like to pass on.
- First get good at welding, or shell out to have it done
- Second, don't be afraid of the project. There are many
who have done this conversion and can offer help if you really mess up.
- Finally, do not start this project until you have
absolutely every piece that you will
need. Do your homework, and plan well. It pays off.
I spent a whole year planning, and when it came time to do everything, I ran
into fewer snags than most people, and completed the project in less overall
time. Don't get yourself down about "not having the fabrication skills needed."
Anyone with half of a brain and who likes to do some work on their car/truck
will be able to do this project.
Writeup by Darrell Krueger (fullreversal)
First posted by ruff ryda 420
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