Roadmaster Active Suspension Project

Ford’s Explorer Sport Trac has become a popular truck for people who are looking for
versatility. It can be used as a 4-door every day driver for transporting passengers and can
just as easily serve as a pickup for hauling cargo or pulling a trailer. Whether it is being used
as a “people carrier” or cargo hauler, many Sport Trac owners have found their Sport Trac
hauls and tows better after the rear suspension is stiffened up. However, nobody wants a
buckboard ride, so one of the best options is to install Roadmaster’s Active Suspension.
The Roadmaster Active Suspension is designed to improve handling, stability, and
load carrying ability, eliminate axle wrap and wheel hop, with or without a load, for vehicles
with rear leaf springs. It strengthens the rear leaf springs by absorbing the load, rather than
resisting it, thereby ensuring a much more comfortable ride. The kits are available for full size
pick-ups and vans and also for shorter wheelbase vehicles such as the Ford Explorer line and
other similar SUV’s. Roadmaster has designed the Active Suspension to be a complete bolt
on installation with NO welding or drilling and eliminates the need for additional leaf blades to
be added to the leaf springs, which sometimes harden the ride of the vehicle.
Following are the steps for installing the Roadmaster Active Suspension in a 2001 Ford
Explorer Sport Trac 4X4 with a completely stock suspension. If you plan to do your own
installation, read over the instructions included
with the kit before starting. Roadmaster also
offers a toll free technical support line, so you
can get answers to any specific questions you
have.
The differences in the rear suspension
of this Sport Trac after installation were
immediately noticeable. The rear feels more
stable, handles bumps/pot holes much better
and there is much less body roll during
cornering and lane changes. There is no
doubt that for people who load the bed or tow
a heavy trailer that it will be a big
improvement.
The part number for the Sport Trac is
MKI (XBF)-ST and can be bought from Martel
Bothers Performance and other suppliers.
As is the case whenever working
beneath a vehicle all the usual safety
precautions apply: make sure the vehicle is on
flat level ground before jacking it up, use good
strong jack stands, a good jack, chock the
wheels and wear appropriate hand and eye
protective gear.
I would recommend following the
directions that come with the kit and using this
project for information specific to the Sport
Trac.
Figure 1
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1. Figure 1 illustrates everything in the box; all parts are listed in the instructions also.
The Threaded Rod (E) and Lock Nuts (G) are already together but you will have to remove
the threaded rod from the Tension Spring (D) before installation because it is threaded into
the spring to far. I assume it is for shipping purposes to fit into the box. This is a good time to
acquaint yourself with the parts and read through the directions before getting started.
2. First chock the front wheels
and jack up the rear from the
center of the rear differential.
Not everyone will agree with
jacking from there but it works
for me and is also in the
directions. (This is also a good time
to check out the rear suspension and
brakes for wear.) The jack stands
were placed on the front of the
leaf springs, but can just as
easily be placed on the frame.
Jack
high
enough
for
suspension to hand down to its
fullest without hitting the ground.
3. The next step is to remove
the bottom bolt from the shock.
This can be done with an 18
mm socket on a ½” drive
ratchet for the nut and a 15
mm open end or box wrench
to hold back on the head of the
bolt. The shock can now be
moved a little to the side while
working on the U-bolts on the
rear diff.
4. Using an 18 mm socket (deep socket makes
it easier) on a ratchet remove the 4 nuts from
the U-bolts holding the rear diff. onto the leaf
springs. The rear diff. is sitting on the leaf
springs so it will not really move. You should
still have the jack ready under the center of the
rear diff. because you will be using it to raise
the rear off of the springs after removing the
nuts and sliding the U-bolts to the side. The
clamp plate will now drop off, and under it you
will see a nut on a bolt that is holding the pack
of leaf springs together.
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5. First jack the rear diff. off of the
springs about 4 or 5 inches. Then you
have to hold the spring leafs together
so they don’t move. Do this with a 6”
C-clamp as close to the center of the
leafs as possible. You can now see
there is a small stud sticking up which
is the top of the bolt that holds the
leafs together. The top of that bolt is
not a hex head it is round, hold it with
a vice-grip pliers and removed the nut
on the bottom with a 15 mm socket
on a ratchet. Refer to the three
illustrations below.
6. In the first illustration below is the original leaf bolt on the bottom and on top the new bolt Leaf
Bolt (I) and the Spacer (H). The new bolt is a little longer than the original bolt it is necessary to cut
off around 3/8”. Run the nut up the bolt and cut it with a hack saw then run the nut off to fix any
threads damaged while making the cut. With the spacer on top install the bolt back into the leaf
springs and tighten it up. Once tight you can remove the C-clamp.
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7. Put the Cup Bearing (B) on the Cap Screw (A) and
insert it through the hole in the Axle Anchor Bracket
(F) and tighten down a nut all the way. Put some
grease on the cup bearing where it touches the
bracket.
The (F) bracket has 2 holes, the hole closest to the 90
degree bend was used, refer to the illustration below
for more of an explanation. Place the bracket over the
spacer sticking out of the leaf spring and make sure it
is lined up straight with the leaf spring. Lower the rear
diff onto the head of the bolt making sure to get it lined
up correctly. There is a bracket welded to the diff that
has a hole in the bottom, that hole goes over the head
of the bolt holding the leaf’s together.
8. Once everything is seated
and lined up put the U-bolts
back in place and get the
clamp plate in position and put
the nuts back on the U-bolts.
Make sure nothing moved
before tightening them back up
all the way. You can also put
the shock back in position and
bolt that up too at this time.
(You can refer to steps 8 & 9 in
the Roadmaster instructions for
more information and a couple
illustrations of what it looks like
bolted back together with the (F)
bracket in place.)
9. This step can be done two different ways. Fit the two-piece Eye Bracket (C) together with the
3-allen head screws and the Nylock nuts and tighten them up. Remove the lower bolt on the
rear leaf spring shackle using a 13/16” socket and swing the shackle towards the back of the
truck out of the way. It may be necessary to lower the spare tire to pull the bolt out all the way.
Place the Eye Bracket (C) over the “eye” end of the leaf spring and replace the shackle bolt.
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If you don’t want to remove the shackle bolt then this can be done the way is says on the
Roadmaster instructions. Slide the eye section of the two-piece Eye Bracket (C) through the
opening between of eye of the leaf spring and the shackle. Refer to the three illustrations
below. That is easier than taking the shackle bolt off, but then you have to assemble the two
pieces of the Eye Bracket on top of the leaf spring while holding your head in the wheel well.
This puts you in a hard position to work in and is more time consuming, if you have some
extra time and don’t mind taking the shackle bolt off it is easier to assemble it outside the
truck and do it as stated above.
10. At this point put the
Threaded Rod (E), Cup Bearing
(B) & Lock Nuts (G) together
with the Eye Bracket and
tightened up the nuts at the end
and leave the other 2 nuts loose
about half way on the threaded
rod.
11. Thread the Tension Spring (D)
about 1” onto the Threaded Rod. Put
some grease on the cup bearing.
Later on you will screw the threaded
rod further into the tension spring.
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12. Thread the Cap Screw into the tension spring all the way up to the nut. Hold back on the
spring and tighten the nut to lock the cap screw and spring together. Like stated earlier since
the first hole was used in the Axle Anchor Bracket the head of the Cap Screw is a little close to
the rear diff. It is not really a problem, use a vice-grip pliers to hold the Cap Screw and tighten
the nut against the Tension Spring with an open-end wrench.
13. Using an open-end wrench
hold back on the lock nuts on
the Eye Bracket side and either
turn the cap screw with an Allen
wrench or grab the tension
spring and turn it by hand. Keep
turning in the direction that
makes the spring open up until
the openings are about 1 mm
apart or about the size of a
quarter. The instructions say a
dime, but the video of the
installation from the Roadmaster
web site said a quarter is fine.
Tighten the 2 lock nuts so the
spring cannot move.
That’s it you’re done! Below are a few illustrations of the finished product. If you like you could
paint the Lock Nuts, Cup Bearings and Threaded Rods and let them dry before installing to keep them
from rusting.
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Now go to the passenger side and
do the same.
Note: The only thing you need to
know is that there is a small
bracket bolted to the Clamp Plate.
That bracket holds the emergency
brake cable on the passenger
side only. Other than that the
install on the passenger side is
exactly the same as what you saw
above.
Links:
Roadmaster Active Suspension
Installation Video on the Roadmaster web site
www.MySportTrac.com
Martel Brothers Performance
John Brancaccio Jr.
Signature Not
Verified
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Digitally signed by John
Brancaccio Jr.
DN: cn=John Brancaccio Jr.
Date: 2002.07.15 16:10:35
-05'00'
Reason: I am the author of
this document