IHC suspension GM 1500 User manual

2007-2018 GM 1500
5” rear drop- reverse hanger
Applies to all 2wd and 4WD. All cabs.
IF your IHC Suspension product has a damaged or missing part,
please contact customer service directly and a new replacement
part will be sent to you immediately. For warranty issues, please
return to the place of installation and contact IHC Suspension.
[phone]
Monday-Friday 8AM-6PM CST
Or
EMAIL: [e-mail]
WEBSITE: www.ihcsuspension.com
LIMITED LIFETIME WARRANTY
This unique product warranty proves our commitment to the quality and reliability of every product that IHC Suspension
manufactures. The IHC Suspension product warranty only extends to the original purchaser of any IHC Suspension
product, if it breaks, we will give you a new part. Warranty does not apply to discontinued parts.
Our Limited Lifetime Warranty excludes the following IHC Suspension items, bushings, bump stops, ball joints, and shock
absorbers. These parts are subject to wear and are not considered defective when worn. They are warranted for 12
months from the date of purchase for defects in workmanship.
This product warranty is voided if the vehicle is not aligned after kit installation and proper maintenance is routinely
done.
Product purchased directly from IHC Suspension has a 30-day return policy on uninstalled products from the date of
purchase (may be subject to restocking fee). Uninstalled product returns must be in the original IHC Suspension
packaging. Please call 956-424-6901 to get an RMA# for any return. Customer is responsible for shipping costs back to
IHC Suspension. Returns without RMA# will be refused. Contact IHC Suspension directly about any potentially defective
parts prior to removal from vehicle.
IHC Suspension products are NOT intended for off-road abuse. Any damage or failure as a result of abuse voids the
warranty of the IHC Suspension product. IHC Suspension is NOT responsible for any subsequent damages to any related
vehicle parts due to misuse, abuse, improper installation, or lack of maintenance. Furthermore, IHC Suspension reserves
the right to change, modify or cancel this warranty without prior notice.

READ INSTRUCTIONS THOROUGHLY AND COMPLETELY BEFORE BEGINNING INSTALLATION.
INSTALLATION BY A CERTIFIED PROFESSIONAL TECHNICIAN IS HIGHLY RECOMMENDED.
IHC Suspension IS NOT RESPONSIBLE FOR ANY DAMAGE OR FAILURE RESULTING FROM IMPROPER INSTALLATION.
Safety Warning
MISUSE OF THIS PRODUCT COULD LEAD TO INJURY OR DEATH.
Suspension systems or components that enhance the on and off-road performance of your vehicle may cause it to handle differently
than it did from the factory. Extreme care must be used to prevent loss of control during abrupt maneuvers.
Always operate your vehicle at reduced speeds to ensure your ability to control your vehicle under all driving conditions. Failure to
drive safely may result in serious injury or death to driver and passengers.
Driver and passengers must ALWAYS wear your seat belts, avoid quick sharp turns and other sudden maneuvers. IHC Suspension
does not recommend the combined use of suspension drop spindles, drop struts, drop springs or other lowering devices.
You should never operate your vehicle under the influence of alcohol or drugs.
Constant maintenance is required to keep your vehicle safe. Thoroughly inspect your vehicle before and after every drag race/race
use.
It is the responsibility of the retailer and/or the installer to review all state and local laws, with the end user of this product, related
to bumper height laws and the lowering of their vehicle before the purchase and installation of any IHC Suspension products.
It is the responsibility of the driver/s to check their surrounding area for obstructions, people, and animals before moving the
vehicle.
All lowered vehicles may have increased blind spots; damage, injury and/or death can occur if these instructions are not followed.
Installation Warning
All steps and procedures described in these instructions were performed while the vehicle was properly supported on a two-post
vehicle lift with safety jacks.
Use caution during all disassembly and assembly steps to ensure suspension components are not over extended causing damage to
any vehicle components and parts included in this kit.
Included instructions are guidelines only for recommended procedures and are not meant to be definitive. Installer is responsible to
insure a safe and controllable vehicle after performing modifications.
IHC Suspension recommends the use of an OE Service Manual for model/year of vehicle when disassembly and assembly of factory
and related components. Unless otherwise specified, tighten all bolts and fasteners to standard torque specifications listed within
the OE Service Manual.
Suspension components that use rubber or urethane bushings should be tightened with the vehicle at normal ride height. This will
prevent premature wear or failure of the bushing and maintain ride comfort.
Larger tire and wheel combinations may increase leverage on suspension, steering, and related components. Due to payload options
and initial ride height variances, the amount of drop is a base figure. Final ride height dimensions may vary in accordance with
original vehicle ride height. Always measure the vehicle ride height prior to beginning installation.

PRE-INSTALLATION MEASUREMENTS
It is imperative that you record the following measurements and factory components in the
tables below. IHC Suspension tests and records as much data from each application as
available at the time of product development. Vehicle manufacturers may change components
or add models with different options. Recording and not exceeding the fender-to-hub-center
IHC Suspension calls out will ensure the drop on the vehicle is correct.
These measurements will affect the performance of this lowering kit. Failure to ensure proper
stock conditions may result in over lowering, causing premature failure on ball joints, if 4wd,
axles, CV boots and drivetrain. Over lowering a vehicle will also result in an incorrect wheel
alignment. This will wear tires incorrectly. Incorrect alignment will cause poor vehicle handling
issues including but not limited to under steer. Over lowering the vehicle will also cause
incorrect suspension geometry resulting in poor ride quality accompanied by pops and clunks
which are symptoms of prematurely wearing components.
Failure to adjust head lamps may cause dangerous driving conditions for you and other drivers
on the road. Record the head lamp position before the installation of this lowering kit and
adjust to original factory position after the completion to ensure a safe and enjoyable
experience. Refer to Owner’s Manual.
VEHICLE HEIGHT MEASURMENTS
DRIVER BEFORE
DRIVER AFTER
PASS BEFORE
PASS AFTER
FRONT
REAR
**MEASUREMENT IS TO BE PERFORMED FROM CENTER OF HUB TO FENDER EDGE STRAIGHT
UP FROM HUB **
•Make sure vehicle is on leveled pavement.
•All 4 tires are same size (if running stagger fitment measurement will
vary)
•All 4 tires have corrected air pressure.

INSTALLATION WARNING
IHC Suspension recommends all steps and procedures described in these instructions be performed while the
vehicle is properly supported on a two-post vehicle lift with safety jacks.
Otherwise, park vehicle on a clean flat surface and block the rear wheels for safety. Engage the parking brake.
Disconnect the vehicle power source at the ground terminal on the battery. Lock the steering wheel in the
straightforward position with the column lock or steering wheel locking device.
Raise the front of the vehicle and support with safety jack stands at each frame rail behind the lower control
arms.
Before starting installation
IHC Suspension highly recommends that the installation of this product be performed by a professional technician
with experience working on and installing suspension products. Professional knowledge and skill will typically
yield the best installation results. If you need an installer in your area, please contact IHC Suspension Customer
Service to find one of our IHC Suspension Authorized dealers.
INSTALLATION BY A PROFESSIONAL IS HIGHLY RECOMMENDED
•A Factory Service Manual for your specific Year / Make / Model is highly recommended for reference
during installation.
•All lifted vehicles may require additional driveline modifications and / or balancing.
•A vehicle alignment is REQUIRED after installation of this product.
•Speedometer / Computer recalibration is required if changing +/- 10% from factory tire diameter.
•A vehicle lift or hoist greatly reduces installation time.
•Installation time estimates are based on an available vehicle hoist.
Vehicle must be in excellent operating condition. Repair or replace any and all worn or damaged components
prior to installation of lowering kit

1. Disconnect the negative terminal on the battery. Jack up the front end of the truck and support the frame rails
with jack stands.
2. Install jack stand in front to properly secure vehicle. NEVER WORK UNDER AN UNSUPPORTED VEHICLE!
3. Remove the rear tires and Support rear differential with jack. Refer to pic.
4. Disconnect ABS wiring on Passenger NOTE: DO NOT damage RED safety clip.
Support rear axle
Unclip ABS clip
Disconnect ABS connector

5. Disconnect ABS wiring clip and connector on DRIVER side. NOTE: DO NOT damage red safety clip.
6. Disconnect BRAKE line clip and wiring harness on DRIVER side
Unclip ABS clip
Disconnect ABS connector
Disconnect brake clip
Unclip wiring from frame

7. Remove BRAKE bracket. Refer to pic.
8. Remove PARKING BRAKE hanger and bracket. Refer to pic
Remove brake bracket
Bracket removed
Remove
Remove
Remove

9. Remove U bolts and lower DIFF down several inches while checking ABS wiring and brake line. NOTE do not over
extend any lines. Refer to PIC
10. The TOW hitch must be removed. Refer to pics.
Remove U bolts
Lower DIFF down
Remove
Remove

11. Remove 13mm behind license plate. There are 2. One on each side. Refer to pic.
12. Carefully with the help of 2 person. REMOVE TOW HITCH
Remove
Remove
Hitch Removed
Tow Hitch

13. Unclip rear exhaust hanger. Refer to pic
14. Remove rear shackles from hanger on both sides. Refer to pic
Unclip hanger
Remove shackles
Remove shackles

15. With the help of 2 person. Move transmission jack over to PASS side while flipping the leaf under DIFF. Repeat to
both sides. Refer to pic
NOTE: CAREFULL NOT TO PULL DIFF TO FAR BACK. DRIVESHAFT MAY FALL OUT OF TRANSMISSION!
16. Vehicle should have both leaf pack under DIFF. refer to pic
Move axle
Both leaf spring under DIFF
Move Leaf
Pack
Move axle
Move Leaf
Pack
Flipping axle DRIVER side
Flipping axle PASS side

17. Flip leaf pack center pin bolt. Clamp leaf pack and with vise grip hold head of bolt. Refer to pic below.
18. Rear bump stops must be completely removed. Remove bump stop grommet and cut bump stop flush with
frame. NOTE:
Remove bump stop grommet
Cut bump stop flush

19. IF truck is single cab skip to step 27. (single cab 5” rear drop includes IHC 1” lift shackles)
20. Remove rear OEM hanger. You will need to cut x on rivets and with air hammer remove. Refer to pic
21. Cut hanger re-enforcement off to completely remove OEM rear hanger.
Cut X into rivet
Hammer river out
Cut out hanger re-enforcement

22. Present IHC hanger to frame. Move hanger upward til meets bed pinch weld. Make a marking on both sides.
Refer to pic.
23. With cutting wheel cut upward to bend. With hammer bend pinch weld. Refer to pics
Mark hanger
CUT Here
Bend to make clearance

24. Install IHC reverse hanger to highest setting. Use IHC hardware that was included. TORQUE to 55FT-lbs
25. Trim OEM shackle bolt. Perform step 23. And 24 on PASS and DRIVER side. Refer to pic
Bolt up hanger
TORQUE to 55FT-LBS
Cut shackle bolt
Cut ¼”

26. Raise leaf pack and install OEM shackle on IHC reverse hanger. DO NOT tighten yet.
27. Install IHC flip kit saddle. Refer to pic on left.
28. Raise DIFF upward and install top plate and bottom plate. TORQUE U BOLTS to 110 FT-LBS.
29. Insert IHC inner sleeve to IHC shocks and install IHC shocks. TORQUE to 80 FT-LBS
Install saddle
Install top plate, bottom plate, and U bolts
Install inner sleeve
Install drop shocks

30. Re-install trailer hitch
31. Install the wheels and lower the vehicle to the ground.
32. TORQUE rear shackle to 100 FT-LBS
33. Torque the lug nuts to the wheel manufacturers specs. Jounce the vehicle to settle the suspension to the new
ride height. Reconnect the battery ground terminal.
FAILURE TO PERFORM THE POST INSPECTION CHECKS MAY RESULT IN VEHICLE COMPONENT DAMAGE
AND/OR PERSONAL INJURY OR DEATH TO THE DRIVER AND/OR OTHERS
Final Checks & Adjustments
Once the vehicle is lowered to the ground, check all parts which have rubber, Delrin or urethane components to
ensure proper torque. Torque lug nuts to the wheel manufacturer specs. Move vehicle backwards and forwards
a short distance to allow suspension components to adjust. Turn the front wheels completely left then right and
verify adequate tire, wheel, brake line, and ABS wire clearance. Test and inspect steering, brake and suspension
components for tightness and proper operation. Inspect brakes hoses and ABS lines for adequate slack at full
extension, adjust, as necessary.
MAINTENANCE
RECHECK ALL HARDWARE FOR PROPER TORQUE VALUES AFTER 500 MILES, AND THEN PERIODICALLY AT EACH
SERVICE INTERVAL THEREAFTER. RECOMMENDED TO PERFORM MAINTENANCE ON ALL BALL JOINTS AND
CONTROL ARMS. ADD GREASE EVERY 6 MONTHS OR EVERY 10K MILES. FAILURE TO PERFORM MAINTENANCE
WILL CAUSE PREMATURE WEAR ON BALL JOINTS AND BUSHING.
Vehicle Handling Warning
Lowering the height of your vehicle lowers the center of gravity and can affect stability and control. Use caution
on turns and when making steering corrections. Vehicles with larger tires and wheels will handle differently than
stock vehicles. Take time to familiarize yourself with the handling of your vehicle.
Wheel Alignment/Headlamp Adjustment
It is necessary to have a proper and professional wheel alignment performed by a certified alignment technician.
Align the vehicle to IHC Recommended specifications. It is recommended that your vehicle alignment be
checked after any race/drag race driving. In addition to your vehicle alignment, for your safety and others, it is
necessary to check and adjust your vehicle headlamps for proper aim and alignment. If the vehicle is equipped
with active or passive safety/collision monitoring and/or avoidance systems including, but not limited to,
camera- or radar-based systems, check and adjust your vehicle’s systems for proper aim and function.
Questions or concerns email [e-mail] or call 956-424-6901 M-F 8am-5pm PST