Wally, our K5, morphed again. This time in response to a bent and
twisted front axle housing, a desire for better side clearance,
a bunch of bent up metal and of course a desire to improve
Here it is on
the trail in Poteau:
Here are some
shop pics of the recent changes. Here you can see the stripped
chassis with the new tube work in the previously open door areas
and the raised nose.
This is the
repaired t-case crossmember with the rear suspension mounting
brackets. It was bent up to the point the crossmember was
hitting the 205 so now it's beefed up and trussed to prevent
the new "boatside" job on the rocker area. Up to this point, the
nerf bars were in the same location as they had been with the
full body, now they fit the rest of the truggy much better.
Here are a
couple of pics of the configuration before summer '05. After the
rolls in Farmington we ran the truck a couple more times and
then started on the rebuild. The front was converted to a full
tube structure and the original body panels were beat to fit.
The factory core support that was used in the original taper job
was pretty mangled so custom radiator and cooler mounts were
built into the new tube structure. The winch was also integrated
on a new lighter weight mount and some headlight/blinker
housings were added so we would at least have DOT legal
headlights and signals. These pics are all from our Rubicon trip
the first of July '03.
As for performance, the truck is a whole new beast since the
body was removed. It still weighs in around 5200# but is about
1000# lighter, somewhere around a foot narrower and the ends
taper in from there. We used to ask if we could fit on trails,
at this point, we don't bother. All restrictions have been
removed. There's still room to carry the kids in the back
(luckily they're still small) and/or enough gear to spend a long
day on the trail. It's a very fun truck to drive.
below is the only photo we have of the truck after the original
taper job. It really was a clean looking vehicle for about 2
days. Some advice: take pics at every oportunity if you care to
remember what your rig looked like, it may not stay nice very
long. If anyone has pics they took at the Supercrawl check in
that they would like to share, we'd sure like to see them.
as of 10/8/02, we tubed out the rear of the K5, mounted a fuel
cell, changed the cage design, tapered the nose, and mounted bed
skins in the rear. Then took it to the UROC Supercrawl and
rolled it. Oops.
as of 8/24/02, we linked up the rear suspension and put the
coils over the shocks. We also went with triple rate springs all
around. We'll be adding some shop pics of the system but here
are some action shots from Upper Helldorado and Pritchett Canyon
You can see the lower arms for the triangle
for the lateral location and the upper arms run parallel to the
frame. The lower arms also start above the axle tube in the rear
for maximum ground clearance and to keep the arms flat for best
torque control and to minimize axle steer under articulation.
Here's a shot of the mock up in the shop:
info on the rest of the truck and the older leaf spring rear
suspension that we ran from June'01 to Aug. '02.
contains a lot of pretty large pictures. This means there's lots
of cool details but it takes a long time to load over a phone
line. Have patience, it will be worth it.
attending and competing (as a spotter) in Fourwheeler's Top
Truck Challenge in 2000, we were hooked and basically decided to
build our shop K5 into a serious competitor for the title of
"TOP TRUCK". After competing in TTC2000, we knew that a truck
built to do well in this competition would be a good vehicle for
just about any type of off road use, so we didn't feel we would
be too specialized for real world use after the event.
We had a few criteria that we felt were important after watching
and competing in TTC. We really felt that there was no way to
win without a 40" or bigger tire, wanted big block power just to
make sure we could spin the tires and knew that it would take a
well engineered, built and maintained rig to do well. Our
components were chosen from the ground up specifically to do
TSL Swampers were the choice as the best balance of a truly huge
tire without a lot of width or added rotating mass. The TTC
rocks are big and the mud is deep and the only way to get true
ground clearance is with big tires. We grooved them to get more
biting edges and increase the flex in the carcass of the tire
for better grip. The wheel choice came down to the last minute,
but Trail Ready came through with a set of prototype 16.5"
beadlock wheels that worked out really well. We were able to use
5" of backspacing on the wheels to keep the track width
reasonable, and keep the majority of the tire in the fender
without having to run flares. The steering also works well with
the tires centered over the knuckle. The tires pretty much set
how the drivetrain was built due to the torque and power
required to make them work.
We knew that
stout axles were a must (that's pretty much a no-brainer) so the
14 bolt full floater went back into the rear, and a D60 was
built for the front. The Corp 14 bolt full floater had already
been in the truck for several years and had just lost it's place
to a lighter axle when we were running smaller tires, so it was
ready to bolt it. We had disc brakes and a Detroit locker
installed already, so we changed the gears to 5.13's and shaved
the diff to get it ready to thrash. Here are some shots of the
14 bolt shaved and the custom cover we built for it.
We air-arc'd (electric gouging process) the lip off and ground
the rest smooth. This was determined to be the best clearance
gain for the time invested. More could be had by actually
cutting out the bottom of the housing and plating it in, but the
time involved vs. extra clearance gained wasn't nearly as good
as just removing the lip. Plus the external grinding could be
done with the gears installed in a driveway.
We plated the factory cover with 1/4 and 3/16" plate to rock
proof it. You can also see our dual braided lines dropping down
to the axle. One line controls each brake via a cutting brake
We knew we needed a Dana 60 front axle but the final form took a
little while to materialize. We eventually came to the
conclusion that it would be reasonably economical to use a
Tera60R diff housing and build it to use all GM axles and outer
parts. Even though the diff is on the left side, it uses GM
inner shafts and outer hubs, etc so it's easy to find parts. The
high pinion was necessary to keep the driveshaft angles good
through the entire suspension travel we had planned. By starting
with a brand new housing and tubes we were able to point the
pinion right at the driveshaft like it needed to be, and rotate
the knuckles to retain perfect steering castor. The Tera60R diff
was filled with reverse cut 5.13 gears which gives a nice
strength bonus to the gearset. An ARB air locker was the choice
for the front due to previous good luck with them and the fact
that the truck handles really well with the front unlocked but
needs full spool traction in some of the terrain we play in. 35
spline outer shafts were added along with a drive flange in
place of the locking hub to make sure we didn't break parts.
We knew our
Doubler kit was ideal to handle the tires and the torque
necessary to drive them, so that was set up next. A unique
Doubler was designed using the GM NP203 rotated 90 degrees and a
Ford 205 rotated flat. This let us use a driver's side front
driveshaft for more clearance past the transmission and left
nothing hanging below the frame rails. The 203 and 205 were both
rebuilt and the 205 was modified to use a twin stick shifter
enabling the front wheel drive only position. This helps tighten
the turn radius in tough terrain. The front and rear use 32
spline output shafts with Tom Wood's Custom Driveshaft flanges
for their 1350 high angularity CV driveshafts. Not much to see
here of the Doubler, it's all kind of hidden which is exactly
the point! You can see the top of the NP205 disappearing through
transmission choice was pretty tough. We've always run a TH700
in the truck with no problems, but with increased power and
torque, a TH400 was strongly considered. An beefed up TH700
finally made the cut, mostly due to the availability of an
overdrive, and the lower first gear. We have the ability to run
a 37-38" radial tire at highway speeds, and have a deeper 1st
gear for crawling. They say it's good for 700HP so I think we'll
be OK. It's fitted with a manual valvebody to allow us to run in
any gear any time we want, and about every conceivable beef up
trick you can do to a TH700. We retained our marine type gate
shifter since it works just like we want it.
was a pretty simple choice.We felt that big block torque was
necessary to spin the 42's in the acceleration and the mud and
any other situation that needs pure power. The old 383 may have
been OK with the added gearing of the Doubler, but we wanted
every edge. There was a nicely built 468ci big block in our snow
plow truck that dropped right into the K5. It had been assembled
with 9.5:1 pistons, a balanced rotating assembly and some well
ported factory heads. We did install an Edelbrock multi point
EFI system, JBA headers and a new Comp cam, but overall it was a
pretty easy swap compared to a ground up build. The Edelbrock
EFI was chosen because it controls the fuel and the timing, is
an efficient and powerful multipoint design, and is tunable
using a small handheld computer furnished with the kit. No
laptop is necessary to change any of the operating parameters so
we can make it do anything we want at any time. The headers are
JBA shorties designed for a late model Vortec truck and were
basically chosen for ground clearance. Frame rail mods were
required to make them fit but they allow everything to be tucked
up and away from the big rocks.
The airbox was custom built by a local sheet metal shop with a
5" diameter neck for the snorkel hose or for a conical air
There's not a lot of room for the motor left here! Passenger
side view above, Driver's Side of the motor is below. It's
pretty easy to take the pictures since there are no inner
were a major criteria in the design of the supension and layout
of the drivetrain. We knew that reliability is the A#1 priority
so strength of the components and attention to the angularity
throughout the travel were VERY important. We used Tom Wood's
Custom Driveshafts' special 1350 high angle CV jointed shafts to
make sure there were no problems. They're good to 30+ degrees of
motion at the CV and we got 36 degrees with some custom
handwork. Both diffs use 1350 yokes and ujoints also. We lucked
out on the length of the driveshafts in that both front and rear
can use the same length shaft. That's really convenient since it
allows us to carry one spare, or interchange them if need be.
suspension is where the true engineering came in. Our overall
goal was 14-15" of vertical wheel travel, the best handling
possible, quality fade free damping, and enough strength to live
through some minor "crashes" while still staying tucked up
enough to give the truck good overall ground clearance. We're
not asking too much here are we?
Lift height is about 6" in the suspension and we also have a 1"
body lift. It measures about 15" from the top of the front axle
to the bottom of the frame and is pretty adjustable given the
coilovers allow you to change ride height by several inches. We
picked this supension height because it allowed the suspension
room to work without the front diff hitting the motor while
still keeping a pretty low center of gravity.
We boxed the
frame from the front end to behind the transfer cases to add
strength and bracing to take the new loads of the link and coil
suspension. The roll cage has been frame mounted for several
years and a few new points were added to make the frame as rigid
Link and coil
suspension was chosen for the front to give the steering
response, wheel travel, and articulation needed for all around
use. Previous buildups using leaf springs with high quality
shocks and various steering setups indicated that the level of
performance we were after just wasn't there without the precise
axle location of a linked up suspension. We did consider
separate coils and shocks, but by the time you mount a 2.5"
shock with a separate spring, it's easier and cheaper to just
mount the coilover shock and be done. So King 2.5" coilovers got
the nod. This picture shows the construction of the suspension
and the installation of the AGR Rockram hydraulic assist
cylinder. The ram is mounted behind the axle to keep it out of
the way of the steering linkage and the rocks.
The photo below shows the routing of the brakeline, ARB Heavy
Duty air line and the breather hose from the axle. We used a
single flexible brakeline and a "T" at the axle instead of 2
The steering system seems pretty complex, and it definitely more
involved than a stock type or regular crossover setup. Steering
systems really only need to achieve 1 goal, turn the tires to
the stops all the time and not steer itself as the suspension
moves. We used the AGR Rock Ram system to get the power to move
the tires when it's bound up.
The linkage geometry came about for a couple of reasons. One is
the new link suspension allowed enough articulation and steering
to run the tire into the steering box on the outside of the
frame rail. So the box had to move inside the frame somewhere
and the easy place to snake the steering shaft to the box was
with the box in the front right corner of the frame. This
location also let us use an idler arm in the steering which made
it easier to set up the angles to eliminate bump and roll steer.
It's all very dense but works VERY well.
The above picture shows the steering box mount and linkage, the
photo below shows the mounts for the panhard bar and the idler
arm. Note the weld in frame repair kit from the previous
retained leaf springs for simplicity but the springs were
stretched to 63" and are a custom ORD pack. We moved the rear
axle back 3" to increase departure angle and lengthen the
wheelbase a little. The 2.5" King shocks were mounted to the
ubolt plates and run through the floor to custom upper mounts.
We haven't measured the rear wheel travel but it's pretty safe
to say we got our 15" of vertical. Traction bars were added to
keep the pinion in line since we now had the power and traction
to really rip stuff up. The bars work well for keeping the
driveshaft alive and don't compromise clearance by a lot but we
are looking into ways to streamline the mounts.
Here's the rear shackle, it was custom built longer and wider
than stock to have a good arc of motion and still be stable. Our
old shackle fllip bracket is still mounted backwards on the
frame from the previous suspension buildup.
ramp tested about 860 on a 30 degree test ramp at the event so
we know the suspension will move!
already had good bumpers and a nice cage, so the interior was
classed up with some racing buckets and some additional cage
bracing and that's about it. We did have to build a good sized
tunnel in the floor to accommodate the transfer cases and the
shifters were custom built to fit in with the cage. The door
panels were also swapped out to match the overall tan and green
color scheme. This shows the custom glovebox we built to have
lockable storage. It also houses the computer, fuses, and relays
for the EFI system to make them totally weatherproof. The
snorkel is pretty obvious too.
Below is the rear of the truck, shows the rear shock mounting
hoops and rear cage.
And here's the driver's side interior.
We stopped by
Moab on the way back from TTC and took some pics to show the
overall clearance under the truck.
TTC lineup at the acceleration event: Never thought my K5 on
42's would seems so short.
1st: Brian Waddell ('72 Suburban)
2nd: Stephen Watson ('82 K5)
3rd: Ferris McCullom ('30 Ford)
placing: (at least what we know at this point, June '01)
Engineering: ORD 82K5
Acceleration: ORD 82K5 or '72 'Burb (both were pretty quick)
Braking: Don't know
Tow Test: White F150 and the Burb were pretty close, along with
the Moeser Dozer (C30)
Mud Pit: the Burb had the only full run
Frame Twister: The hybrid S10 made a record setting run for the
Mini-Rubicon: ORD 82K5 set a new record, zero points, about 3
Hill climb: ORD 82K5
Obstacle course: ORD 82K5
Tank Trap: Hybrid S10 sets another record