|
|
Product Reviews
Extended Shock
Mounts with Rancho Shocks
In order to take full advantage of our leaf spring articulation,
something had to be done with the factory shock mount locations that
were severely limiting travel. We had seen a number of 4x4's of
different makes and models using 1980 Ford F-250 front shock towers
simply cut to the length needed and bolted in place. With a price around
30 dollars for the set and a simple bolt on installation, the Ford
towers were a logical choice.
Because our project Blazer is currently a daily driver, we needed a
shock that would allow a fair amount of travel for off-road use, yet be
able to soak up everyday on-pavement bumps and pot-holes. With
13-1/4" of shock travel and the ability to adjust the desired performance
curve: firm for off-road; soft for street, and mid-range for highway use,
the RS9012's were just what we were looking for.
| Ford F-250 Shock Towers |
Old RS5000 - New RS9012 |
|
|
The Ford F-250 towers are almost 15" long, so they will have to be cut down to fit
properly depending on the amount of lift. The first thing that has
to be done is to remove the front wheel and securely place a jack-stand
under the front axle, it is important to place a jack-stand under the
axle and not to lift the vehicle by the bumper, doing so will flex the
springs and result in an inaccurate shock measurement. If you have the
factory quad shock setup the lower mount will have to be removed, we
simply drilled out the factory rivets and pounded out the shanks so we
had a clear frame to work with. Also note that if your truck originally
came with a 10-bolt front axle as ours did, an extra bump stop bracket
located on the passenger side will have to be removed. With a clear
frame to work with and the old shock removed we began by installing the
new RS9012 in our new shock tower and lower axle mount. This way we
could move the tower and shock around to check for clearance and proper
placement. The towers will have to be angled back a bit to allow proper
movement of the shock from compression to full extension. We decided to
mount the shocks with 6-1/2" of the chrome rod showing, almost dead
center of the 13-1/4" of total shock travel, keep in mind we have
5" of suspension lift, placement of the shocks will vary depending
on amount of lift each vehicle has.
| 10-bolt Bump Stop |
Old Shock Mount
Removed |
Inner Fender Cut |
Fuel Lines in frame
Rail |
|
|
|
 |
We decided to use the
two existing rivet holes in the frame by enlarging them to 1/2" and
then marking and drilling matching holes in the shock tower itself. For
the third bolt, we drilled a small pilot hole through the tower and
frame followed by a 1/2" hole. Before drilling an extra hole to
mount the tower - one word of caution - on the passenger side, the fuel
lines run on the inside of the frame rail. After all three 1/2"
bolts were secure it was time to trim the excess length from the tower.
We found it easier to just trim the tower while it was installed on the
frame, so out came the saws-all and off came about 4" of shock
tower. We also decided to bevel the sides of the tower for a little more
room when the shock fully compresses, it also gave it that finished
look. After all three bolts were tightened with lock-tight we cut a
small area of inner fender just above the shock tower to make sure there
were not going to be any clearance problems. At this point the RS9012
shocks can be installed.
| Shock Tower Installed |
Drilling Pilot Hole |
Cutting Extra Length |
 |
 |
|
| Angle Cut |
Shock Installed |
Shock Compressed |
 |
 |
 |
Because custom fabrication and welding were needed to install the extra
long RS9012 shocks in the rear as well as exhaust modifications, we decided to have
Off Road Ltd.
in Aurora Colorado perform this upgrade. Without a major body lift the
only real way to extend the shock mounts in the rear is to either extend
them through the floor or angle them in towards the center of the
vehicle using a custom brace. Installing shocks through the floor was
not considered for obvious reasons so we went with the custom brace
welded in between the frame rails which ended up working real well. Off
Road Ltd. put a small upward bend on each side of the brace made from
1-1/2" OD tube to extend the mount as close as possible to the
body. On the axle, the new mounts were pushed out as far as possible to
maximize stability while keeping them level with the bottom of the axle
tube to minimize over hang. This setup works very well, the idea is to
angle the shocks in towards the center allowing taller shocks to be
installed which will provide additional travel, but keep in mind, if
they are angled in to far the shocks will start to loose their
functionality as well as their stability.
| Rear Shocks
Installed |
Top View |
Custom Top Mounts |
|
|
 |
| Custom Bottom Mounts |
Top View |
Shock Compressed |
 |
 |
 |
Before the
extended shocks were installed our project Blazer was run up a 25 degree
RTI ramp scoring a 817, next it was driven up the ramp backwards scoring
a 867, in both directions the short RS5000 shocks in the stock location
were severely limiting our articulation. After the extended mounts and
RS9012 shocks were installed it scored a 930 forward and 977 backwards.
Needless to say we were quite happy that a full-size 4x4 with common
leaf springs and no trick suspension parts with extended shocks could
score in the mid 900's on a 25 degree ramp.
| 977 RTI Backward |
930 RTI Forward |
Front Droop |
|
 |
 |
The RS9012
shocks are working out quite well and we love the ability to adjust them
from soft to firm for all types of on and off-road use. Look for an
upcoming "Extended Shock Mounts II" article where we will
review Rancho's duel in-cab remote system that will allow us to choose
between five different ride settings from within the comfort of the cab.
- Steve Fox
|
Five settings adjust both compression and rebound damping for precise ride
control.
