Have
you ever asked yourself why manufacturers have always equipped trucks
with such stupid-looking wheel and tire packages? Yes, there are some
decent-looking wheels that are available, but why do the tires have
to be so small? Don't the Big Three realize that it's kind of
ridiculous to make a bad-ass looking truck only to throw a set of
pizza-cutter wheels and tires under it and call it good? Yeah, they
understand. But they have some good reasons behind this ironic
behavior.
Here
are just a few: Big tires make the truck harder to stop. Stopping
ability affects the hauling capacity. Big tires are more difficult to
get rolling. This increased resistance negatively affects fuel
economy and hauling capacity. Big tires add weight, resistance, and
greater force against suspension and steering components, which will
reduce the life of parts like bushings, ball joints, tie rod ends,
steering gear. So rather than fight against physics, it seems the
automakers have some secret agreement that they will not be
competitive in the wheel and tire area of their offering to the
market. This allows them to keep costs down and vehicle performance
numbers up. But don't worry. All of this doesn't mean you have
kiss your solid steering and good tow rating goodbye if you want
good-looking wheels and tires. We've installed and have been
testing what we think is the ultimate steering upgrade.
Chrysler
started using a larger steering gear in 2010 that has improved the
steering stability of their HD trucks. Still, after adding a 2.5-inch
leveling kit, 20-inch wheels, and 325/60 20R tires, our steering had
significant wobble after hitting things like pot holes or diagonal
cracks in the road. It wasn't a death wobble by any means, but it
would only be a matter of time before our steering components were
worn enough to become a death wobble. So we set out to find the best
solution we could to eliminate wobble. If our wheels don't wobble,
the amount of wear that will occur to our steering components is
minimal. If your truck has any steering wobble, it's best to stop
it in its tracks. It's possible to round out the holes where the
track bar mounts to the frame and axle if steering wobble is allowed
to go unchecked.
In
order to eliminate our steering wobble symptoms, we first installed a
steering box stabilizer bracket that we ordered from PSC Motorsports.
This bracket captures the end of the pitman arm in a bearing under
the steering gear and ties the steering gear to both the passenger
and driver side of the truck's frame. This helps isolate the
steering gear from any movement or wobble that may feed back from
wheels when hitting bumps or cracks.
The
steering bracket kit comes with a new pitman arm retaining nut that
has a shaft on the end which the bearing will go around.
This
heavy bearing for the pitman arm has a grease fitting that should be
greased when the rest of the truck gets lubed.
The
new steering bracket will prevent any lateral movement of the
steering gear, which will prevent steering gear wear by limiting
wobble that translates from the wheels, through the steering linkage
and to the gear.
In
an effort to eliminate steering wobble near the source (at the
wheels), we installed a hydraulic steering assist kit that we also
ordered from PSC. We're going to remove the factory steering
stabilizer shock and mount a hydraulic ram in its place. This
location is perfect because it limits the lateral motion of steering
travel from side to side, which is where steering wobble begins. The
PSC kit comes with everything we needed: a steering gear that's
been ported for left and right pressure hydraulic lines, hydraulic
hoses and connectors, a hydraulic ram that is the correct length for
our application, and steel tabs to mount the ram.
The
hydraulic ram assists the steering gear by using hydraulic pressure
to push the ram left when the gear is turned left and vice versa.
This works well because the ram works more efficiently with the
hydraulic fluid pushed by the pump because of its design and because
of where the ram is positioned in line with the wheels. Because there
is hydraulic pressure on the left and right side of the ram and the
fluid inputs are different, the ram acts as a barrier to wobble from
the wheels. The ram doesn't want to move unless the fluid from the
steering gear dictates the action with fluid being pushed either to
the left or right side of the ram. The power steering system on the
truck will take about an extra quart of fluid, which keeps the system
cooler. And the ram takes a significant amount of load off of the
mechanical portion of the steering gear, which will help prolong the
life of the gear.
The
new steering gear has hydraulic ports that the factory gear doesn't.
It's a good idea to keep these caps in the truck in case of a leak
or broken hydraulic hose. Should that occur, we would just cap the
ports like this photo shows and the steering system would perform
like a stock factory steering system.
We
removed both the steering stabilizer shock and its mounting bracket
in order to make room for the hydraulic ram. The new mounts are
nearly in the same location as the stabilizer.
We
determined the mounting location for the ram by measuring the amount
of throw travel that the ram has to the left and right. The ram has 8
inches of travel when fully extended, so we knew that the ram is at
center when it's extended 4 inches. With the ram centered, and the
truck wheels straight, we were able to choose a mounting location on
the axle and tie rod.
We
grinded the paint off of the tie rod and the axle where we needed to
weld the mount tabs for the ram.
It's
important to mount the tabs in a location where we've determined so
that the ram won't contact the axle or pumpkin during any part of
its range of motion. The tabs on the driver's side are welded to
the mount for the OEM steering stabilizer. After the tabs are welded
into place, we primed the bare metal with an acid etch primer and
RustOleum paint to prevent rust.
After
the paint dried, we mounted the ram with grade eight bolts provided
in the kit and attached the hydraulic lines. When mounting the lines
we were careful that the lines weren't going to be pinched by the
track bar or tie rod as the steering moves and the axle moves up and
down. Then we secured the lines with heavy zip ties.
After
all of the plumbing is done, we followed the standard procedure for
bleeding a new power steering gear and pump to purge the system of
any air.
The
final result is a steering wheel that you can turn from lock to lock
while parked on dry pavement by effortlessly using only one finger.
On the road, the steering is solid and wobble-free. Some feed back is
felt on really large potholes, but there's no lingering wobble like
we experienced with the stock steering system. Now the only
noticeable difference between the large 34.5-inch tires and stock
tires is a slight increase in road wander at freeway speeds, which we
attribute to the open tread design of our mud/snow all terrain tires.
In
order to keep our Ram's tow rating, fuel economy, and gear load in
line with what the factory intended, we ordered our Ram with 4:10
gears in the axles. We did this because at the end of the day, we
wanted this truck to drive and perform like it was riding on stock
wheels and tires with 3:73 gears in the axles. After adding a
34.5-inch tire, the 4:10 gears compensate for the taller tires, which
makes our final drive gear ratio almost the same as it would be if we
had 3:73 gears with stock tires. The only thing we haven't
addressed is added effort that the brakes require to stop the truck.
However, the brakes on the fourth generation Ram are pretty solid and
with the factory exhaust brake, it's even less of an issue.
PSC
Motorsports
http://www.pscmotorsports.com
817-270-0102
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