I got to really looking today at the hub assemblies
and the axles I have in the 3/4 ton, and in the 1 ton.
Turns out that the only real difference in the
hub and axle is the length of the assembly from thebacking plate out.
Of course the 1 ton has its leaf springs mounted
closer to the frame, and has its shocks mounted inside the frame rails.
All that I am assuming is to get the load
bearing stuff closer in to allow more capacity.
The 1 ton hub is longer to have a better load
position for the bearings, but for what I'm doing with the COE,
it would be of little importance to have that
longer hub. I may do some towing that would mean some pulling loads,
but definitely would never have a load on the
bed of any significance.
So......... I got to measuring and decided why
not......... I grabbed a pair of the 1 Ton wheels and tires,
removed the single tire from the 3/4 ton, and
tried to mount them. The studs of course matched... I knew that going
in,
but alas the brake drums were too large for the
wheels. Then I had another idea.
The G30 bus axle is essentially the same
hub setup, but being a few years later in vintage (80 vs 73)
the wheels turned out to be different.
And .... they fit!! Obviously the studs will have to be changed,
but with two complete axle assemblies I think
I have enough stuff to take care of that issue.
It does take studs about 1 inch longer, but otherwise,
it is a done deal.
I can't believe I never thought of trying all
this before.
No axle changing, no welding , no cutting, no
new brake setup, no shock mount changing,
no gas tank repositioning, no spring mount changing,
no rerouting of the fuel lines, and brake lines.....
..... nothing but some stud changes. That
whole deal probably saved at least two weeks of refab work. Whew!!!
I have included the photos of how it all works.
The first one is of the rear with the duals obviously
in place on the drivers side, andthe single still there on the passenger
side. 
The next photo is of the spacing of the duals
on that 3/4 ton setup,
and the third photo is of the spacing for the
rear tire on the 1 ton.
It will actually be a better deal to have the
duals on the 3/4 ton axle than on the 1 ton.
It gives an axle overall width with tires of
86", while the 1Ton was 84", so the 3/4 ton will actually be more stable.
The spacing away from the springs is a better
setup too.
If a flat would ever occur on the inside tire
for the 1 ton, I would be a little leery of that happening as there
is only about 15/16" space between the tire sidewall
and the spring.
I could just see a flat coming undone and shredding
itself while beating up that side of a custom built bed and fender arrangement.
The 3/4 ton ends up with right at 2" of space
there, and that I like better.
I have
had for some time 3 chassis to consider using, one being a 80 3/4
ton suburban 4x4 with engine and all.
The second is a 73 C30 1 ton dually
flatbed chassis , and the third is a 77 G30 (bus) dually chassis with
engine & trans too. The
C30 had some frame damage .... it had been in a wreck.... plus the
typical steering fractures of the left front frame rail. That
meant a lot of work to fix, so that went to the end of the list quickly.
The G30 chassis is the typical unibody setup
for small buses, and oddly enough is several inches wider than the
C30, and
doesn't really fit well for the Chev COE
fender width. It does fit a 48-52 Ford COE though.
My 51 Ford COE will get most of that chassis
under it eventually. So... by process of simple elimination
the 3/4
ton frame became the choice.
The use of duals on the rear was an absolute
I felt .... I like the look. So ... what to do?
Adapters are available that do the job, but
a full package to make that happen would have been around a $1000.
The products are good, but I just
didn't want to spend that kind of money if I could figure out a different
way.
I tried the wheels from the C30 .... they wouldn't
fit at all .... they hit the drums.
I then tried the wheels from the G30, and
was very surprised to see that with just a little work,
they would likely fit. Most factory duals
are what are called "hub centered",
so just hogging away at the centers was a little
iffy, but once some measuring showed that only
about .018" was all that needed to be removed,
I tried one wheel that I knew would be a spare anyway,
and found that it would finally work with just
some careful grinding.
I used a small angle grinder and a 4 1/2 x 1/4
wheel. The tolerance for out of round on most wheels is .040"
to .060".
You just have to do an accurate and
on center job while grinding. The unexpected bonus of
the duals
on that suburban rear axle was that there is
more clearance between the tires and the springs,
so fatter tires can be a reality easily
later on. I did change the studs out for the necessary long
ones.
A large hammer and a good brass drift punch did
that whole thing. So duals are now on the 3/4 ton suburban chassis.
I will TIG weld some pads in place on the
hubs to extend the centering part of the hub to properly fit the
dual wheels.
I'll add photos to Bill's web site when
that gets done. Basically it is just adding material beyond
where the centering part exists on the hub, and then do some judicious
grinding or machining to make it all fit well.
The centering part of the hub on the 3/4 ton
is too narrow as is, since the hub was made for a single wheel,
and actually was made to be used with "lug
centered" wheels. Easy to fix though.
One trick there I learned from a friend
that has 40 years in the metal trades...... if you use stainless
welding rod with a TIG welder, the welds are
easily machined, and there is virtually no porosity.
It is important to clean the area well
first.
The front end of the suburban was of course that
for a 4x4, and not what I wanted.
The frame looked suspiciously similar to the
C30, so I did a full measure up, and found that it should work.
I removed the 4x4 front axle... springs
and all, and positioned the C30 1 ton independent
suspension with its steering box in place,
and it fit right in. Some drilling, a bit of crossmember modification,
and the whole frame and suspension setup
will have converted the suburban chassis to a dually arrangement.
Tools used were simple: wrenches,
torch, grinder, and drills. As said earlier, a little
welding will be needed finally,
but all in all the whole process turned out to
be mostly just wrench work, and some typical hot rodder trial and
fit stuff.
One other bonus for the 3/4 ton frame is
that it is flat behind where the cab fits, and allows the placement of
a
sleeper cab with much greater ease. Behind
that will go a flatbed with a hoist setup. I do plan on boxing a
good
part of the frame from the front suspension back
to the rear axle area to add strength.
It is kind of amazing how flexible these frames
are, and indeed that is a design intent, but once you start changing
everything, some added strength is a good
idea I think. The fuel tank is one other feature that I like
with the suburban chassis. It is located behind the rear axle
and gives added safety to the whole setup.
All the fuel lines are there, the filler tube
is easily adapted to a flatbed or pickup style box, and there are even
aftermarket stainless tanks of larger size
readily available. Nifty!
Anyway..... hope all this provides at least
some added options in what you use for a frame and suspension.
It was fun to work through the design and
get what I wanted with little extra cost. I figure the $1400
I have in total for all the three chassis was
well worth the price. I will have two chassis under two COE
trucks,
and a lot of extra parts left over.
I have an extra Chevy 350 engine out of the deal too.