JSPEC1303 3 Inch 3.5 Inch Front Rear Suspension System User Manual
- June 13, 2024
- JSPEC
Table of Contents
- GETTING STARTED
- PRE-INSTALLATION
- REAR DISASSEMBLY
- REAR INSTALLATION
- FRONT DISASSEMBLY
- FRONT BUMP STOP & COIL SPRING INSTALLATION
- QUICKER DISCONNECT INSTALLATION
- FRONT CAM LOCK INSTALLATION
- FRONT ADJUSTABLE TRACK BAR
- FINAL FRONT INSTALLATION STEP
- STICKER INSTALLATION
- References
- Read User Manual Online (PDF format)
- Download This Manual (PDF format)
1303 3 Inch 3.5 Inch Front Rear Suspension System
User Manual
GETTING STARTED
Read all warnings, instructions, notes and cautions before you begin the
installation.
WHO SHOULD INSTALL THIS?
We recommend that this system be installed by a professional mechanic. The
installer will need professional knowledge of special tools required for
installation as well as assembly and disassembly procedures.
STAYING SAFE AND LEGAL
- If you fail to drive your lifted and modified vehicle safely it may result in serious injury or death.
- Exercise caution: A lifted vehicle is at greater risk for rollovers or loss of control, especially during abrupt maneuvers.
- Always wear your seat belt, reduce your speed and avoid sharp turns.
- Never operate your vehicle under the influence of drugs or alcohol.
- Consult local and state laws for the legality of your ride height.
BEFORE YOU BEGIN INSTALLATION
- Needed items: OE service manual for your vehicle, safety glasses, and any special tools as indicated in these instructions as well as the following tools: assorted metric and standard wrenches, hammer, hydraulic floor jack and a set of jack stands.
- Ride Height: Measure the initial ride height of your vehicle prior to installation. Final ride height may vary depending on the factory height of your vehicle.
- Tires and rims: Larger tire and rim combinations can increase leverage and cause additional stress to suspension, steering, and related components. When installing larger than OE tires and rims, the following components should be inspected for wear every 2500-5000 miles: ball joints, tie rod ends, wheel bearings, track bar bushings, pitman arm.
- Drive line vibrations: Some vehicles may experience drive line vibration after installation of this suspension system. Possible remedies for this include: tuning angles, replacement of slider on shaft, lengthening or truing of shaft, and/or replacing u-joints.
- Installation without a hoist: We recommend completing the rear alterations first if no hoist is available.
TRACTION CONTROL COMPLIANT
In an effort to reduce the risk of rollover crashes the National Highway
Traffic Safety Administration (NHTSA) established the Federal Motor Vehicle
Safety Standard (FMVSS) No.
126 requiring all new passenger vehicles under 10,000 lbs GVWR include an
electronic stability control (ESC) system as standard equipment. Effective
August 2012 this law requires aftermarket products to be compliant with these
same standards.
VISIT 560PLUS.COM FOR MORE INFORMATION!
THANK YOU FOR CHOOSING JSPEC SUSPENSION
TIRE FITMENT
SPORT MODELS
- 3.5″ LIFT – 33×12.50 on 17×8 with 4.5-5″ backspacing no rubbing
- – 35×12.50 on 17×8 with 4.5-5” backspacing rubbing under articulation will occur
- 3.5″ LIFT – 35×12.50 on 17×8 with 4.5-5″ backspacing no rubbing
RUBICON MODELS
- 3.0” LIFT – 37×12.50 on 17×8 with 4.5-5” backspacing will rub under extreme articulation
- 3.0” LIFT – 37×12.50 with stock wheels will not rub fender.
SPECIAL TOOLS REQUIRED
Torque Wrench Die Grinder with carbide bur (LCA cam install)
INSTALLATION TIME
Approximately 5-6 hours
BEFORE YOU BEGIN
The kit comes standard with front shocks intended for use with the factory
front driveshaft. If an aftermarket dual cardan front shaft is used, front
shocks up to 28” (2.5”) or 29” (3.5”) extended can be used.
PRE-INSTALLATION
a. Measure from the center of the wheel up to the bottom edge of the wheel opening.
| Drv| Pass
---|---|---
Front| |
Rear| |
REAR DISASSEMBLY
a. Disconnect the track bar at the axle with the vehicle still on the ground
using a 21mm socket. Save bolt and nut tab.
b. Raise and support the vehicle with jack stands positioned in front of the
lower suspension arm brackets. Remove the tires.
c. Remove the sway bar links from the axle and sway bar (18mm)
d. Support the axle with a jack under the center of the differential and
remove the shocks from the frame and axle (18mm), save hardware .
REAR INSTALLATION
COIL SPRINGS, SWAY BAR LINKS, BUMP STOPS
Rear bump stop spacers will require bolt pack J106
a. Lower the axle enough to remove the factory springs. Note the orientation
of the upper spring isolotors. Make sure there is adequate slack on all brake
lines.
Note: Before installation be sure to transfer the coil wrap from the factory
coils onto the upper windings of the new coils.
b. Install the shorter pair of JSPEC coils springs with the larger windings on
top into the rear of the vehicle with the orientation similar to stock. The
upper isolators have a locating pin that fits into a hole in the frame. Raise
the axle to compress the springs enough to hold them in place.
c. Set the length of the provided rear sway bar links with the booted joints
to 11-3/4” between the ball stud centers and install to the outside of the
sway bar and axle mount [1,2].
Note: Sway bar hole willl be tight, it may require being enlarged just
slightly to get the stud to push through. A round file or rotary bit can be
used.d. Install the rear bump
stop spacers on the axle. Fasten the bump stop spacer to the axle with the
5/16” x 7/8” bolts, nuts and washers. Torque bolts to 20 ft-lbs. (1/2”) [3 –
3” extension shown]e. The shocks come with the
bushings and upper spacers pre-installed. Install the shocks body down with
the wide upper mount at the frame. Slide the shock up into the mount.
Tip: The bushings will have to compress slightly to get the shock in the
mount, try walking the shock into place by tilting the shock back and forth
against the spacers while pushing the shock up into place.
f. Attach the shock to the frame and axle mount with the original hardware.
Torque bolts to 60 ft-lbs. Re-install inner fender liners.
FRONT DISASSEMBLY
a. Disconnect the front track bar (21mm) from the axle. Save bolt and nut tab.
b. Raise the vehicle and support the frame with jack stands behind the front
lower control arm pockets.
c. Remove the wheels.
d. Disconnect the front brake line brackets from the frame rails (10mm)
[4].e. Rubicon models:
Disconnect the front locker wires from the differential.
f. Disconnect the front axle disconnect wiring harness and pull out the (2)
push pins that mount the harness to the axle [5]. g. Disconnect the sway bar links from the axle and sway bar
(18mm). Discard links, save lower hardware [6,7].h. Support the front axle with a hydraulic jack.
Remove the front shocks from the vehicle using a 18mm socket for the top and
18mm socket and wrench on the bottom. Save lower hardware.
i. Lower the front axle and remove the coil springs. As the axle is lowered,
verify all brake and electrical wires have enough slack and the driveshaft
doesn’t bind.
FRONT BUMP STOP & COIL SPRING INSTALLATION
2” Front bump stops will require bolt pack J130, 3” bump stops will require
bolt pack J131
j. Place the provided bump stop extension inside one of the JSPEC front coil
springs. Install the front springs with the bump top extension [8]. Make sure
the spring is seated properly in the axle mount and the top isolator hasn’t
moved from the stock position.k. Attach the bump stop extension to the axle through the
hole in the center of the spring perch. Acces to the nut can be obtained from
the front of the spring perch. Another option is to remove the brake line
bracket temoporarily to gain access to attach the nut from the rear of the
spring perch Torque to approximately 25 ft-lbs.
l. Repeat the spring and bump stop installation on the other side of the
vehicle.
m. Install the new shocks with the factory hardware. The shocks will be
installed with the wide spacers up top and the bushing and sleeve in the
bottom similar to the rear. Torque the bolts to 60 ft-lbs
QUICKER DISCONNECT INSTALLATION
Quicker Disconnects will require bolt pack J127
ALL MODELS
n. Adjust the length of the quicker disconnects to 9” center to center. This
is a good starting point and can be fine tuned once the vehicle is on the
ground if needed.
o. Insert the longer sleeves into the upper bushing and slide the polyurethane
spacer onto the upper sleeve so it will mount towards the swaybar.
p. Using the provided 12mm x 75mm bolts, washers, and nuts loosely fasten the
sway bar links to the sway bar with the bolts going from the outside towards
the frame [9]. NON-RUBICON MODELS
q. The passenger side mount will need to be cut to provide access for the
disconnect post. Cut the mount off vertically just past the weld on the
bracket [10]. This should be about 1-1/4” from the center of the
hole.r. Install the shorter
passenger side post on the side of the track bar mount at the sway bar link
mount location with it pointing outboard [11]. Fasten with the 1/2” nylock nut
and tighten to 65 ft-lbs. s. Install the longer disconnect post on the driver side
axle sway bar link mount with it pointing inboard [12]. Fasten with the 1/2”
nylock nut and tighten to 65 ft-lbs. Tighten the post with the pin hole
parallel to the ground. Slide the polyurethane spacer on the pin up against
the axle tab.
Note: A small screwdriver or punch inserted into the pin hole will keep
the post from turning as you tighten it.t. The kit comes with disconnect retention brackets to
hold the links when the links are disconnected. Install the retention brackets
using the provided 5/16” bolts into the factory hole in the front of the coil
bucket [13]. These are designed to slightly interfere with the edge of the
coil bucket to hold them in place.u. Slide the ends of the disconnects over the retention
bracket posts. Insert click pins to secure. These quicker disconnects can be
more easily attached with the vehicle at ride height.
v. Torque the quicker disconnect to sway bar mounting bolts to 65 ft-lbs.
RUBICON MODELS
Rubicon models have a factory electronic disconnect system. Follow these steps
to solid mount your sway bar links. w. Set the sway bar into disconnect mode
for ease of installation of the links to the axle.
x. Locate the 1-1/4” sleeve and insert it into the passenger side disconnect
bushing.
y. Insert the 1/4” thick spacer and disconnect into the original sway bar link
location [14]. It may be necessary to slightly open up the link opening for
ease of assembly.
z. Fasten the link to the axle with the original hardware. Adjust the length
as necessary to ensure the links do not bind at full droop, depending on the
shocks being installed.aa. Install the remaning longer sleeve on the driver
side and slide the polyurethane spacer onto the sleeve so it will mount
towards the axle mount tab. Install the quicker disconnect to the inboard side
of the axle tab with the original sway bar link hardware.
Note: If the link length was adjusted for the passenger side, match the
length on the driver side link.
ab. Torque the upper and lower hardware to 65 ft-lbs
FRONT CAM LOCK INSTALLATION
If not installing optional JKS control arms or geometry correction brackets,
use the following steps to install the provided alignment cams.
a. With the front axle still supported with a jack, loosen all 4 lower control
arm bolts. Remove the passenger’s side lower ontrol arm bolt at the axle. The
lower control arm mounts are setup with cam stops so they can be changed to
slots for alignment cams.
b. Place the alignment cam between the stops on the axle so that the new bolt
hole is rearward. Mark the area that needs to be removed.
c. Using a die grinder with a carbide burr (preferred), remove the area marked
on both sides of each control arm axle mount. [15]d. Re-install the control arm to the axle with the
factory bolt with cam lock washers. Rotate the cam lock so that the bolt will
be as far back in the slot as possible (most rearward setting = max caster).
Snug the cam hardware so that the cams are retained within the stops. Final
torque will be completed with the weight of the vehicle on the suspension.
[16] Note: Use of a jack on the axle may help to align the cams. Wait for
final cam placement until the other side is complete.e. Repeat cam bolt installation on the driver’s
side.
FRONT ADJUSTABLE TRACK BAR
a. Adjust the length of the track bar to 34”. This is a starting point, final
adjustment can be made once the vehicle is on the ground.
b. Insert the non adjustable end of the track bar into the frame mount with
the clearance bend forward. Use factory hardware. Do not tighten at this time.
FINAL FRONT INSTALLATION STEP
a. Rubicon models: Reattach the locker wire harness to the differential.
b. Install the wheels and torque to the lug nuts to 130 ft-lbs.
c. Lower the vehicle to the ground and bounce the vehicle to settle the
suspension. Torque the front lower control arm bolts at the axle to 207 ft-
lbs. Make sure the cam locks are set so the control arm mounting bolt is in
the rear of the slot the the cams are within the axle tabs.
d. Attach the front track bar to the axle with the OE hardware. Have an
assistance turn the steering wheel to aid in aligning the track bar bolt. Take
measurements to check if the axle is centered. Make an adjustment to the track
bar equal to half of the distance the axle is shifted to one side. Torque the
frame and axle track bar bolts to 115 ft-lbs.
e. Install the rear track bar into the OE bracket with the factory bolt.
Tip: Use an assistant to push on the body of the vehicle to help align
the track bar in the bracket.
f. Torque the track bar bolts to 110 ft-lb
g. Verify tire clearance, trim the front bumper side trim pieces as shown [17]
if necessary on your model.
STICKER INSTALLATION
Sticker installation should be performed when the temperature is above 60°
F.
a. Clean the areas thoroughly with rubbing alcohol to remove any buildup.
b. Carefully place the sticker in the desired location [18 recommended].
c. Rub gently to secure, then press firmly for 30 seconds.
KIT CONTENTS
JSPEC STD COIL SPRINGS
Part No. | Qty | Description |
---|---|---|
034332R | 2 | Front coil springs – Std |
032159R | 2 | Rear coil springs – Std |
JSPEC1303 3-3.5” MAIN BOX KIT
Front Adjustable Track Bar
Part No. | Qty | Description |
---|---|---|
3300 | 1 | Track Bar |
3309 | 1 | Track Bar End |
36274 | 1 | 1-1/4” Jam Nut |
MB01B701740 | 2 | Bushing |
Sway Bar Quicker Disconnects
Part No. | Qty | Description |
---|---|---|
3315 | 1 | Disconnect Retention Bracket – Drv |
3316 | 1 | Disconnect Retention Bracket – Pass |
3010 | 1 | Female |
3011 | 1 | Male |
M00475-BK-01 | 2 | Spherical Bushing |
7050R | 2 | Grease Zerk Cap |
7607 | 2 | Grease Zerk |
36264 | 1 | 5/8 Jam nut |
J127 | 1 | Bolt Pack – Quicker Disconnects |
2 | 12mm-1.75 x 75mm bolt | |
2 | 12mm-1.75 x 75mm prevailing torque nut | |
4 | 12mm flat washer | |
2 | 5/16”-18 x 3/4” bolt | |
2 | 5/16”-18 prevailing torque nut | |
4 | 5/16” SAE flat washer | |
3005 | 2 | Quick Pin (2001CP) |
M03212-BK-01 | 3 | Offset Polyurethane Spacer |
A1046 | 1 | 03013 Stud w/ nut |
A1045 | 1 | 03017 Stud w/ nut |
65 | 2 | 3/4” X 1.65” Sleeve |
Rubicon Fixed Mount Hardware
Part No. | Qty | Description |
---|---|---|
65 | 1 | 3/4” X 1.65” Sleeve |
162 | 1 | 3/4” x 1.25” Sleeve |
1499 | 1 | 1/4” Spacer |
JSPEC1303 3-3.5” MAIN BOX KIT (CONT.)
Front Alignment Cams
Part No. | Qty | Description |
---|---|---|
3326 | 4 | Front alignment cam washer |
Bump Stop Extensions
Part No. | Qty | Description |
---|---|---|
3178 | 2 | 2” Alum Bump Spacer – 2.5” only |
J130 | 1 | Bolt Pack – Front Bump Ext. 2.5” only |
2 3/8”-16 x 2-1/2” bolt | ||
2 3/8” USS washer | ||
2 3/8” flange lock nut | ||
J131 | 1 | Bolt Pack – Front Bump Ext. 3.5” only |
2 3/8”-16 x 3-1/2” bolt | ||
2 3/8” USS washer | ||
2 3/8” flange lock nut | ||
3374 | 2 2” Rear Bump Stop Block | |
J106 | 1 | Bolt Pack – Rear Bump Spacers |
4 5/16” x 3/4” bolt | ||
4 5/16” prevailing torque nut | ||
8 5/16” SAE washer |
Rear Sway Bar Links
Part No. | Qty | Description |
---|---|---|
TRE502 | 2 | Rod End with nut |
3065 | 2 | Connecting Rod |
N12FJ | 4 | 1/2” Jam Nut |
3064 | 2 | Shock Eylet Assm |
SB58BK | 2 | Bushing |
51792 | 2 | 5/8 x 1.375 “ Sleeve |
www.jksmfg.com
jks@ridefox.com
517-278-1226
References
- 5/60 Factory Protection Plus - 5/60 Factory Protection Plus
- Jeep Lift Kits, Leveling Kits and Suspension Parts – JKS Manufacturing
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