JSPEC1303 3 Inch 3.5 Inch Front Rear Suspension System User Manual

June 13, 2024
JSPEC

JSPEC - logo 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.JSPEC1303 3 Inch 3.5 Inch Front Rear Suspension System - round
filed. 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]JSPEC1303 3 Inch 3.5 Inch Front Rear Suspension System -
washerse. 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].JSPEC1303 3 Inch 3.5 Inch Front Rear Suspension System - frame
railse. 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]. JSPEC1303 3 Inch 3.5 Inch
Front Rear Suspension System - harnessg. Disconnect the sway bar links from the axle and sway bar (18mm). Discard links, save lower hardware [6,7].JSPEC1303 3 Inch 3.5 Inch
Front Rear Suspension System - sway bar linksh. 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.JSPEC1303 3 Inch 3.5 Inch Front Rear
Suspension System - sway bar linksk. 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].JSPEC1303 3 Inch 3.5 Inch Front Rear Suspension System -
outside towards 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.JSPEC1303 3 Inch 3.5 Inch Front Rear Suspension System - RUBICON
MODELSr. 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. JSPEC1303 3 Inch 3.5 Inch Front Rear Suspension
System - tightens. 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.JSPEC1303 3 Inch 3.5 Inch Front Rear
Suspension System - screwdrivert. 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.JSPEC1303 3 Inch 3.5 Inch Front Rear
Suspension System - coil bucketu. 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.JSPEC1303 3 Inch 3.5 Inch Front Rear Suspension
System - shocks beingaa. 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]JSPEC1303 3 Inch 3.5 Inch
Front Rear Suspension System - both sidesd. 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.JSPEC1303 3 Inch 3.5
Inch Front Rear Suspension System - shocks being 1e. 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.JSPEC1303 3 Inch 3.5 Inch Front Rear Suspension
System - bumper side

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.JSPEC1303 3 Inch
3.5 Inch Front Rear Suspension System - Rub gently

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

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www.jksmfg.com
 jks@ridefox.com 
517-278-1226

References

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