Solid Axle Swap on a ’98
This write-up is provided solely for reference purposes.
Any modification or maintenance that you do to your vehicle is not the
responsibility of All-Terrain Armor. Work done to your vehicle is done AT
YOUR OWN RISK!
In offroading, there are a
numerous different types of suspensions and drivetrains
that you can find underneath different rigs.
For the type of wheeling that I mostly do here in
The axle that I used for the swap was a Dana 44 that came
out of an ’88 Jeep Grand Wagoneer because it has a
matching lug pattern and WMS to WMS axle width to my Toyota rear axle, it has a
driver side differential, and it is a cheap and easy to find axle. Some people
prefer to use a Toyota axle for their swap to keep everything in their truck
one manufacturer, but since the Tacoma is wider than the earlier Pickup, I
would need to find an FJ80 axle which is a little harder to come by and it
would require modification of my transfer case setup since it has a passenger
side differential and the Tacoma has a driver side transfer case. I bought the
axle from a fellow club member who regeared it to
4.10s which I already had in my rear axle, and he replaced the bearings and
seals so it was all set to go. I also decided to use the leaf springs that came
from the factory on the Wagoneer since they were
included with the axle and looked to be in decent condition. Along with all
these parts, I was also given a set of flat top knuckles that would fit on the
axle for high steer.
- The project started long before any
cutting ever took place. There was a lot of planning, parts collecting,
and fabricating/machining involved before the truck saw any work. First I
decided that I would use the flat top knuckles I had to run only a
passenger side high steer arm for the drag link, and I would keep the low
steer arms for the tie rod since this setup would be much less expensive,
easier, and slightly stronger than running a complete high steer setup.
After receiving a used high steer arm, I brought the passenger side
knuckle into work to sandblast it, mill the top flat, then drill and tap
the top surface for the steering arm. See this helpful article about
knuckle milling http://web.acsalaska.net/~cvandor/wilhelm/flattop.html
Here is the finished passenger side knuckle
compared to the driver’s side which was not used.
Here is it installed on the axle with the high
steer arm attached using a stud kit and ball joints from www.harshterrain.com which is a vendor
I have had very good experiences with.
- The next item to fabricate was the
steering box mounting plates. I cut these by hand out of ¼” steel plate
and drilled ¾” holes so that I could weld in sleeves between both plates
and the frame of the vehicle
I ordered the sleeves from www.weldtab.com along with other small tabs and
gussets. This is another good vendor that I would recommend for various small
items like this. Here is my
- Next I made the front spring hangers out
of 3x2x1/4” steel tube, ¼” angle, and ¼” flat steel. I built in a gusset
that would give the hanger more contact area to weld to the frame.
- After welding the front spring hangers
onto the frame of the truck, it was time to disconnect everything and chop
off the IFS. Here is the IFS sitting next to the new solid axle.
- After grinding everything down to bear
frame, it was time to start the fun part of building the truck. I first
drilled the frame for the steering box so that two bolts would go through
the frame and the sleeve for the third would sit directly atop the frame.
This gave me the most amount of material to weld to the frame. I also had
to trim away some of the sheet metal in order to fit the steering box.
- As soon as it arrived, I installed my
2wd T100 oil pan and oil pickup. This is necessary to make clearance for
the differential on the new axle. I
ordered the parts through
T100 2wd
oil pan # 12101-65030
T100 2wd oil pan pickup tube # 15104-62060
T100 2wd pickup tube gasket # 15147-62020
T100 2wd dipstick # 15301-62060
T100 2wd dipstick guide tube # 11452-62060
T100 2wd union # 90405-10033
(Don’t forget to grab some
gasket-maker!)
7. With the axle assembled and the front
spring hangers welded on, I could mock up the axle and figure out where I
needed to weld on my spring shackle hangers. I received my new spring perches
from www.summitracing.com and I
ordered 6” shackles and shackle hangers from www.ruffstuffspecialties.com
Dan at Ruff Stuff is a great
guy to work with and I would order from him any day of the week. After setting
up the suspension and resting the truck on the axle, it was apparent that the
axle had been moved way too far forward.
Although
I wanted my axle forward, this was too much so I redrilled
my spring perches and u-bolt plates 1.5” forward, thereby moving the axle 1.5”
back. This is where I have left, and am happy with, the placement of the axle.
I also trimmed the fenders to extend the wheel well as far forward as possible
- My
next task was to fabricate a new steering shaft. First I had to modify the
shaft to convert it from double u-joint to single. Then I used
.75x.75x.125” and 1x1x.125” to make a collapsible square tube shaft. This
must be collapsible or else it would spear the driver through the chest in
the event of a high speed head-on accident which I would like to try and
avoid. I did tack weld the joint together once it was in the truck to get
rid of any slop but only enough that it would still break if it needed to.
In
this picture you can also see the frame support plate that I made and welded
rear of the steering box to help handle the steering stresses not intended for
by this frame
I
also had to modify my firewall plate to seal up the new steering shaft since it
now comes out of the cab at a different angle. I whipped up something using an
old shock boot, the old firewall seal, and lots of silicone sealant. I also siliconed on a PVC cap to seal up where the shaft
previously left the firewall.
- At
this point I had a mobile truck that I could back straight out of the
garage only. I was still waiting on
10. My steering and brake lines finally showed up so I
threw them in only to find out I needed to ream out the hole in my high steer
arm for the drag link end. I had to order a new reamer so that set me back a
few days but everything worked out.
11. After
taking a test drive, the steering wheel felt like it wanted to follow any dips
in the road. This is when I realized that I had welded on my spring perches
with only 1* of castor, so I ordered steel 4* pinion shims from www.bluetorchfab.com . This took care
of my steering issue and brought my truck back to daily driver status after a
month and a half of building. Shortly afterwards I repainted the truck since
the old camo job was getting worn out so I tried
redoing it using the roll on paint method. You can see my paintjob write-up
here http://www.atarmor.com/writeups/paintwriteup.htm
12. To get my 4WD back, I ordered a
13. Go wheelin’
The end product is a truck that
rides great on the road, great on the trail, and performs better than ever offroad. I could not be happier with the finished product
and it is a very rewarding feeling to be able to improve the vehicle’s offroad performance so much while still retaining streetability.
Working 99% by myself and ordering/fabricating parts as I went, this
project took about a month and a half from the first cut of the IFS to a driveable vehicle. Obviously I did not go into extraordinary
detail simply because there is physically too much information to cover and if
you feel competent to tackle such a project by yourself, you should have the mechanical
inclination required to figure the little stuff out.
This project is very involved,
time consuming, and expensive. If you decide to attempt a project like this,
just remember that your life will be riding on it so do not cut any corners.
See you on the trails,
Eric Amato
ATArmor.com
This write-up is provided solely for reference purposes.
Any modification or maintenance that you do to your vehicle is not the
responsibility of All-Terrain Armor. Work done to your vehicle is done AT
YOUR OWN RISK!