 | In the last
installment of the build up the Original Unlimited project the main
focus was how the different components of the drive train were bolted
together and then mounted on the rolling chassis. Months and months of
work have gone into the project since the last article was posted but
like any other frame up over all systems are often not completed until
close to the completion of the project. This time around the focus will
be on the steering, braking system, drive shafts/parking brake and the
fueling system. |
| This Original Unlimited
might be a 1970 CJ-6 but there are very few original items left. The
engine is a 305 TPI Chevy V8 from a 91 Camaro, the transmission was a
Mantrans, LLC supplied NV4500 and this was mated to the original Dana
18 transfer case with Teralow gears via some Advance Adapters magic.
The axles are a later model Dana 30 front axle and the original Dana 44
rear axle. Both axles were stuffed with 4:88 gears and the rear was
treated to a Detroit Soflocker. While all of the main drive train
components were in place the rig still needed to be able to get power
to the ground. |
 | The first name
that comes to mind when thinking of a place to get custom drive shafts
made is Tom Wood's Custom Drive Shafts. After a few questions were
answered Tom gave easy to follow instructions on how to figure out the
measurement of the drive shafts. After the measurements were provided
front and rear drive shafts were built using the high quality
components that Tom Wood's shop is known for. Both drive shafts were
built with longer slip splines to allow the shaft to accommodate more
axle travel. The rear shaft was built as a CV model to help eliminate
any drive shaft vibrations. Once the shafts were built they were left
with the natural metal finish and then clear coated to ensure that the
shafts did not rust. | |
 | Past experience had
shown that the transfer case mounted drum brake was not adequate to use
as a parking brake on this trail Jeep. It was usually not adequate on
even stock Jeeps as it would often fill with oil and grime and simply
cease working. A decision was made when the transfer case was rebuilt
that the original drum brake would be replaced by a disc brake. Tom
Wood came to the rescue in this department as well. Tom Wood's outfit
offers a kit that bolted a disc brake onto the new companion flange
that was required to run with the new CV drive shaft. This rotor is
slotted and bolts behind the companion flange. The kit also includes a
lever operated mechanical disc brake caliper and a universal bracket. |
 | The only difficulty encountered
in mounting the rotor was that the supplied bolts would not clear the
rear out put housing. After some hex cap machine screws were ground a
bit everything cleared fine. Once the rotor was in place the caliper
and bracket were held in their location to determine where the best
mounting location would be. For the Dana 18 transfer case the bolts
that hold the rear PTO cover proved to be a very convenient location to
bolt our bracket to. A flange was cut from plate steel and then welded
to the universal bracket that came with the kit. Conveniently this
universal bracket proved to be just the right height to
be welded to our new crescent moon shaped flange. |
 | To provide enough
rigidity a triangular gusset was cut and welded in place. After the
paint was sprayed and dry the new assembly was bolted in place. The
current plan is to use a NOS parking brake lever from an M151 military
vehicle. This handle was obtained from Nelson's Surplus Jeep Parts
(330-482-5191) in Columbiana, OH. The handle is very similar to the
type used on tow motors if finding NOS Mutt levers proves to be too
difficult. |
 | Once the drive
shafts were in place and power could be sent to the ground the braking
system needed to be addressed. A used YJ power brake system was
purchased from JU Vendor DAVEY who owns DaveysJeeps.com
and deals in used Jeep parts. From the original proportioning valve out
to the wheels stainless steel brake lines were provided by Classic
Tube. Because of the unique nature of the project and the year of the
Jeep pre-bent lines were not available. Classic Tube sent plenty of
fittings and a coil of 3/16" stainless tubing from which custom brake
lines were fashioned. |
| Be careful in choosing
a flaring kit to flare stainless lines. Most kits are not up to the
task and it is easy to destroy a flaring kit in the process. Once all
of the stainless lines were in place the braided stainless hoses that
Classic tube built to the specified length were bolted in place. The
end result is a high quality stainless brake system that sends power
from a YJ power brake set up out to the large 6 bolt caliper bracket
type disc brakes in the front and the stock 10x2 inch drum brakes in
the rear.
|
 | In addition to
bending tubing for the brake system stainless lines had to be routed
for the fuel injection system. Tuned Port Injection motors are a high
pressure fuel system that requires a high pressure electric pump. The
core of the fueling system was provided by Howell Engine Developments
in the form of an externally mounted electric fuel pump. Once this pump
was bolted down to the frame custom lines were made. Using fuel line
repair kits from Napa the stainless lines were mated to the original
flexible lines that ran from the motor to the frame rail in the Camaro. |
 |
These factory flexible hoses were in good shape but they used an o-ring
type fitting that would be difficult to duplicate. Using compression
fittings that came in the fuel line repair kits the proper ends were
attached to the new stainless line. Using a combination of special fuel
injection rubber hose, bulk stainless line from 4wd Hardware and a
couple of adaptor fittings the lines were able to be run from the front
to the back and the stock style CJ sending unit was able to be
retained. |
 | Howell Engine Developments
was a valuable source of both parts and information in this swap. Many
of the miscellaneous components such as the air filter, coil,
distributor cap, O2 sensor, fuel pump, fuel filter and even a new
computer chip were all available from Howell and it certainly made the
swap easier. In addition to the piece parts Howell can furnish wiring
harnesses or even complete fuel injection systems to make a reliable
EFI system a possibility in any Jeep. |
 | With the fueling
system complete the steering system needed to be addressed. The TPI V8
already had a good power steering pump installed. Matt Peters of Peters
Off Road fabricated a frame mount to attach our Mullins built Saginaw
800 series box to. |
 | This steering box has a variable ratio and is used
in many large cars and pick up trucks. Many people do not know that
Mullins is the steering box division of Borgeson Universal Company. |
 | Borgeson has been in the u-joint business for 90 years and have long
been a staple in performance steering components whether in a hot rod
or 4x4. A Borgeson steering shaft was used to mate the Comanche pickup
steering column to the Mullins built steering box. The new steering
shaft uses high quality needle bearings
that offer unprecedented performance and endurance. |
 | Power flows to the
box via a stock 80-86 6 cylinder CJ hose that was obtained from 4wd
Hardware. The return line proved to be a bit tougher because of the
custom frame cross member and the fact that the new steering box used
two metric fittings while the CJ return line was standard measurement
(the CJ return line fitting used an 18mm wrench but the threads were
standard measurement). |
| A return fitting was kindly provided by a
coworker who had ended up with some extra fittings from the new rack
and pinion system he was putting in his hotrod. A 45 degree flare was
put into the line and a rubber hose was clamped on since the return
line is not under pressure. This is very similar to how the stock return
line was built. A steering box brace keeps the box from over stressing
the frame and a super beefy steering linkage from Bid Daddy Off Road
was used. To help protect the steering linkage the tie rod and drag
link were flipped on top of the steering arms by reaming the top of the
holes and using tappets to fill in the bottom. Because of this
modification a stock CJ power steering pitman arm was able to be used
rather than a drop model despite the 4.5 inches of suspension lift. The
pitman arm, HD tie rod kit and steering box brace were all sourced from
4wd Hardware. |
 | With the drive
shafts bolted in place, the brake and fueling systems routed and the
steering system ready to go the body work, paint and interior were next
on the list of things to do. Be sure to tune in for the next
installment of this build up as paint and bed liner are sprayed, body
armor is applied, the body parts are bolted in place and this Original
Unlimited CJ-6 begins to take shape.
|
