Squeezing more wheel travel out of twin traction beam
The ‘80-96 Ford Bronco is arguably one of the greatest
platforms ever built for all types of wheeling. They’re not too big and
cumbersome, yet have enough room to store all your gear with plenty of room for
passengers even during long road trips through the middle of nowhere. The short
wheelbase makes them highly maneuverable in the dirt in almost any situation.
Much of the Bronco’s off-road prowess can be attributed to the versatility of
the Twin Traction Beam front suspension. While some will tell you TTB is
absolute garbage and is the greatest shortcoming of Ford 4x4s of the ’80s and
’90s, we’re hoping to set the record straight and show you just how awesome a
TTB suspension can be in the dirt.
We will concede that you really can’t expect TTB to
withstand hardcore off-road abuse with massive 40-inch tires at wide open
throttle. That will usually end with broken U-joints or, worse yet, broken
axleshafts. While massive rubber and big horsepower might be out the window, a
long travel TTB suspension can turn an otherwise unassuming 4x4 into a go-fast,
whoop-eating monster that is still able to crawl and flex its way through a
trail like a champ.
The ‘80-96 Ford
Bronco is arguably one of the greatest platforms ever built for all types of
wheeling.
So now you’re probably wondering how a suspension that
seemingly can’t survive the abuse of 40-inch tires could possibly survive life
in a hostile desert environment at blazing speeds. Follow along as we show you
how we reworked our Bronco’s old suspension to soak up some serious terrain
while still delivering decent road manners.
1. Our Bronco has seen its share of suspension kits (it even
had Project Juice’s old Skyjacker kit at one point) but once we decided we
wanted to leave all our friends in the dust when bombing around the desert, we
realized that a Cut and Turned TTB setup was the only way to go. What is a cut
and turned beam? There’s more than a few ways to skin this cat but the gist of
it is that the beams are modified and plated to the point where if you ran a
4-inch lift coil, you would not have to use a drop bracket to correct the
camber. This results in more ground clearance as well as a bit more wheel
travel when done right. Notice how the tie-rod ends are kept pretty close in
alignment to the axleshafts. This is dictated by the pitman arm that you choose
to run on your truck.
2. While a Cut and Turned Twin Traction Beam suspension can
work with a stock pitman arm, Solo Motorsports recommends the use of a 4-inch
drop-pitman arm (most aftermarket lift kit companies sell it as PN FD400) to
correct the angle on the steering links. The drop-pitman arm will align the
steering links with the axleshafts while the suspension cycles, which helps
keep bumpsteer to a minimum.
3. No long travel truck is complete without a set of custom
coilover mounts. While you can run a cut and turned beam setup with the factory
coil buckets, you’ll be missing out on much more wheel travel and better shock
choices without going to a fabricated mount. Solo Motorsports designed their
coilover mounts to work on both Bronco and F Series trucks that were equipped
with TTB. They’ve really done their homework to get the shock angle just right
not interfering with anything in the engine bay. While our Bronco is setup with
single coilovers right over the beams, the Solo Motorsports coilover mounts
also feature integrated bypass shock mounting tabs in case we decide to run a
set of bypass shocks to chase down race trucks in the future.
4. Solo Motorsports ties in their coilover mounts with a
crossbar that stiffens up the front end and keeps the frame rails from moving
around while hitting major whoops at high speeds. We ordered our Bilstein 9100
coilovers with 90-degree fittings and remote reservoir hoses in 14 inches to
get them to tuck up over the crossbar without interfering with under-hood
components.
Solo Motorsports
ties in their coilover mounts with a crossbar that stiffens up the front end
and keeps the frame rails from moving around while hitting major whoops at high
speeds.
5. One of the key ingredients to getting some serious wheel
travel numbers out of a TTB suspension involves the radius arms. While they
seem simple in design, Solo Motorsports has done lots of research and
development to get the caster angle right throughout the range of suspension arc.
Too much or too little could have adverse effects especially at high speeds.
6. Strong pivot brackets can make the difference when going
fast in the dirt especially when you consider the fact that Heim joints allow
the suspension to cycle to full droop without much resistance when bombing
around rougher sections of desert. Solo Motorsports uses ¼-inch steel for their
radius arm pivot brackets and a big beefy 1¼-inch Aurora Heim joint to
withstand the abuse that comes with the go-fast territory.
7. While the factory rubber snubber/bumpstop is fine for a
stock suspension, they simply don’t hold a candle to what hydraulic bumpstops
can do when hitting deep G-outs at speed. We ordered a set of 3-inch stroke FOX
2.0 hydraulic bumpstops to help soak up deep holes, and we can honestly tell
you they’ve kept the ride quality smoother than butter.
8. To keep the shocks from pulling themselves apart when
airing out the suspension, Solo Motorsports added a set of 12-inch Kartek limit
straps. Keep in mind that a limit strap will stretch 1 inch for every foot of
limit strap so make sure to factor that into your limit strap placement. We
didn’t need to modify our brake lines since our Bronco was already equipped
with a set of longer Pro Comp braided steel brake lines but Solo Motorsports
did have to build a mount for the line since the stock coil buckets are used to
retain them.
9. One area that needs to be addressed when going for bigger
wheel travel numbers on a TTB suspension is the center U-joint on the
passenger-side axleshaft. Most people shave down the center U-joint until it
can safely rotate at full droop. Keep in mind that limit straps will stretch
about an inch for every foot of limit strap so be sure to take this into
account when shaving down your center U-joint.
10. The passenger side beam needs to be clearance a bit so
that the axleshaft can spin freely without binding when the beam cycles through
its travel. It’s nothing a grinder can’t take care of. 11. Without question,
one of the most important aspects of any serious long travel suspension is
shocks. They can make or break the way a truck soaks up the whoops at high
speeds, and it’s not really an area you want to pinch pennies on. We’ve had
great success running Bilstein 9100 coilovers on The Juice project Bronco so we
decided to go with a set of 12-inch stroke Bilstein 9100 remote reservoir
coilovers for our go fast build. We called up Mirage Racing Products in Santee,
California, and ordered a set of dual 12-inch Hypercoil springs to hold up the
frontend of our Bronco. We chose to go with a spring rate of 350 pounds over
450 pounds per Solo Motorsports’ recommendation and now that we’ve had the
opportunity to raise some hell in the dirt with all our newfound wheel-travel,
we’re glad we listened to their advice. On-road driving manners are great but
the best part is we can scoot through sections of whoops at much higher speeds
than we ever could before in the kind of terrain that would force other
off-road vehicles to slow down.
They can make or
break the way a truck soaks up the whoops at high speeds, and it’s not really
an area you want to pinch pennies on. We’ve had great success running Bilstein
9100 coilovers on The Juice project Bronco so we decided to go with a set of
12-inch stroke Bilstein 9100 remote reservoir coilovers for our go fast build.
