'35-'40 Ford Mustang II Front Air Spring Suspension
Note: A qualified welder should do all welding. A qualified mechanic should
do the wheel alignment and brake installation. During the final assembly
use a thread-locking compound such as Loctite 271.
These instructions are used in several kit forms and may include more
information than you need for your kit's installation. Please keep this
in mind.
1. PREPARING THE FRAME
Mark the location of the axle centerline of the frame
Unbolt all the old suspension and steering components
Tack weld two braces 4" forward of the axle center line to the top
and bottom of the frame. (This will keep the frame from moving when the
cross member is removed)
Remove the original cross member by drilling out the attaching rivets and
square up top and bottom up of frame
Tack weld in the boxing plates and make sure they are square and half of
boxing plates into the frame edge of frame lip
Weld in boxing plates
Grind the welds
2. INSTALLING THE LOWER CROSSMEMBER
Fit the cross member squarely against the bottom of the frame with the
rack & pinion mounts on the front. The centerline of the cross member
should be on the axle centerline
Tack weld the lower cross member to the frame with chassis set up a the
rake you want and lower arm pins parallel to the ground
3. INSTALLING THE SPRING MOUNTS
Position the spring towers on the top of the frame centered on the axle
centerline. The towers should be outboard of the frame and mounted such
that they slope down to the rear of the vehicle. (The angle of this slope
should not be changed, as it controls the amount of antidive)
Tack weld the spring towers in place
4. INSTALLING THE RETRO FIT KIT:
Locate the bump stop against the outside of the frame and the back side
of the spring tower. The bottom of the bracket should be 1/2" below
the frame
Tack weld the bracket to the frame. If you are using the bolt-on type, then
you can clamp them in place
Locate the upper shock mount 4 1/2" behind the spring hat, and 1/2"
below the top of the frame and tack weld in place. If you are using the
bolt-on type, then you can clamp them in place
Checking for alignment: when performing this operation only tighten the
fasteners enough to contain the parts and prevent them from moving, this
way the same fasteners may be used when you final assemble the parts to
the required torque
5. Install the lower control arms with the acorn nut in the front and the
nyloc nut in the rear. Do not tighten completely
Screw in the 90 degree air fitting so that it faces away from the center
and install the upper spring adaptor to the air spring using the 3/8-16x1"
bolts with the 7/16" head
Install the air spring on the lower control arm with regular 3/8-16x1"
bolts and washers. The slot in the spring adaptor should be leaning away
from the vehicle. If not swap side with the adapters
Slide the air spring adapter in the spring tower and fasten with 7/16-20x3"
bolts and cupped washers. The lower control arm has slots to allow the air
spring to be positioned so that the bottom of the spring moves up and down
directly below the top of the spring. Adjust the spring as necessary using
the slots
Install the front shocks with 7/16-20x3/5" bolt, flat washers, and
nyloc nut
Install the upper control arm using the "T" bolts, flat washers,
and nyloc nuts
Attach spindles
Install the rack & pinion
Raise the lower control arm until it is level (this is the ideal right height)
Align the front suspension
Check that the bump stop hits the lower control arm about 1/2" before
the air spring reaches full bottom (the spring should be 3.3 inches minimum
at this point), and that the shock limits the extension of the air spring
before the air spring is full extended (7.7 inches maximum). The air spring
has 4.9" of travel, from the 2.8" tall to 7.7 tall. The air spring
has no internal device to limit the amount of extension possible, and that
a bump stop is used to limit the compressed height of the air spring to
prevent any damage to the spring or vehicle
If any components need to be moved, move them and recheck the location of
the bump stop and shock absorber
Unbolt the spindles, shocks, air springs, control arms, and the rack &
pinion
6. FINAL ASSEMBLY
Final weld al the components in place. For the bolt-on shock brackets
and bolt-on bump stops, use a transfer punch mark the holes, the drill them
to 5/16. Be careful not to make the holes larger. Clean the chips away.
Do not install the brackets yet!
Remove the two temporary cross members in front of the new cross member
The chassis and suspension parts can now be painted and prepped for final
assembly,
Reattach the air spring with anti-roll-over plated on top and bottom, control
arms, shocks, spindles, and brakes. Make sure to use thread locking compound
where applicable. Fasten the bolt-on brackets using the 3/8 self-tapping
bolts and a thread locking compound such as Loctite 271. Once the self-tapping
bolts are in, they are not to be removed!
Re-align the front suspension and plumb the airlines. When routing the airlines,
keep them away from high heat sources and anything that might pinch or sever
them. Once the air and electric plumbing is finished, check for leaks around
the fittings using soapy water. Once you have determined there are no leaks,
you're new suspension is ready to cruise!
Alignment specifications:
Camber 0 degrees +- 1/4"
Caster +3 degrees -2degrees/+3degrees
Toe in 1/8" +- 1/16"
All measurements taken with the vehicle at ride height:
Torque: 3/8 self=tapping.... 30 ft=lbs
3/8=16 x 1" 20ft=lbs attaches air spring
7/16=20 x 3... 30ft=lbs
|