QA1 RDK52626 Rear Lowering Kit Instruction Manual

: June 14, 2024
: QA1

Table of Contents

PRE INSTALLATION NOTES:
DISASSEMBLY
ASSEMBLY
SHACKLE ASSEMBLY
SHACKLE INSTALLATION
DISCLAIMER / WARRANTY
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QA1 RDK52626 Rear Lowering Kit Instruction Manual

PRE INSTALLATION NOTES:

This installation will require the axle to be installed on top of the leaf springs, which will require removing the axle and repositioning it from its factory position under the leaf springs.

Confirm that all of the hardware listed on page 5 is present before beginning the installation.

DISASSEMBLY

Chock the front tires with the truck in gear (manual transmission) or park (automatic transmission).
Raise and support the rear of the vehicle and support using jack stands at the manufacturers specified locations. NEVER work on or go underneath a vehicle supported only by a jack.
Remove the rear shocks.
Mark the phasing of the driveshaft and remove it from the truck.
Support the rear axle using a jack to take pressure off the leaf springs. Do not apply enough force to raise the truck.
Remove the brake lines, e-brake cables, and ABS sensors from the axle.
While supporting the axle, evenly remove the u-bolts holding the axle to the leaf springs. Retain the u-bolts and hardware to be re-used with this suspension.
With the axle removed from the truck, remove the rear leaf spring shackle to leaf spring mounting bolt from each side of the truck. (Figure 1 , point A)
Remove the shackle to chassis bracket mounting bolt and remove the shackle from the truck. (Figure 1 , point B)
Remove the welds of the factory bump stop boxes and discard. Use caution as to not remove any more material from the frame than necessary. (Figure 2)
Cut both brake line mounting tabs off of the axle. (Figure 3)
Remove the six bolts holding the hitch receiver to the frame. This will allow access to the rear leaf mount that will need to be removed in the following step.
Remove the mounting bolts holding the rear shackle brackets to the frame. (Figure 4)

The rear-most upper bolt on each side of the truck will need to be reused for the new bracket. (Figure 5)
One small weld and a rivet will need to be removed to fully remove the mount. (Figure 6)

ASSEMBLY

Drill and tap a hole around the center where the factory bump stop boxes were located to 3/8”-16 before threading in the included bump stop. (Figure 7)
Unbolt the centering pin of the leaf springs and mount it reverse of the factory location. The centering pin should now protrude on the top side of the leaf spring with the securing nut on the bottom side of the leaf. (Figure 8)
Move the rear axle into position on the top of the leaf springs.
Place the axle mount with the brake line tab towards the rear of the truck under the axle before setting the axle on top of the leaf springs. (Figure 9)

Do not install the factory block between the axle and the leaf springs. All three QA1 mounts are not left/right specific and can be used on either side of the truck.
Place the narrow plate on top of the axle pad with the small hole towards the rear of the truck. (Figure 10)
Install the larger plate to the bottom side of the leaf springs with the large hole in the plate towards the front of the truck and locating on the leaf spring centering pin. Secure the mounts re-using the factory U-bolts. (Figure 8) Evenly torque all U-bolt nuts to 74 lb. ft.

BALLOON #| ITEM #| DESCRIPTION| QTY.
---|---|---|---
1| 9637-687| WELDMENT, SPRING SHACKLE| 2
2| 9032-439| BUSHING, POLY 2-PIECE, BLACK| 4
3| 9033-520| SLEEVE, .875″ OD X .563″ ID X 3.00″ L| 2
4| 9023-116| CAP, GREASE ZERK| 2
5| 9023-119| FITTING, ZERK 1/4-28, STRAIGHT| 2
6| 9033-518| SPACER, 14MM ID X .75″ OD X .86″| 8

SHACKLE ASSEMBLY

A. Push one bushing half (#2) into each end of the QA1 spring shackle (#1).
B. Lightly grease the metal sleeve using marine grease (#3) before inserting it through the bushings.
C. Thread the included grease fitting (#5) into the end of the bushing can with a 7mm socket. Tighten to 37 lb. in.
D. Use 1-2 pumps of marine grease before installing the red grease cap (#4). Do not over grease this part as it will bulge
the bushing halves out of the assembly.

SHACKLE INSTALLATION

Install the new rear leaf hanger in the correct position for the desired drop. (Figure 11)

The rear upper-most hole of the new hanger bracket should be secured with the factory bolt that came out of this location and torqued to 37 lb. ft. The remaining three holes of the bracket should be secured using the included M10x1.5 bolts, 25mm long, with two washers and one nyloc nut per connection. Additional mounting holes can be used for a 4.5” and 5.5” drop. Torque each bracket connection to 53 lb. ft.
Mount the shackle to the frame mount, (narrow end up) using M14x2.0 bolts, 110mm long, with two washers and one nyloc nut per connection. (Figure 12)
Mount the leaf spring to the upper or lower hole of the shackle dependent on the desired drop. (Figure 11) Mount the leaf spring to the shackle using M14x2.0, 25mm long bolts, with two washers and one nyloc nut per connection. Torque both shackle bolts to 70 lb. ft.
Reinstall and bleed the brake lines, e-brake cables, and ABS sensors. The e-brake mounts can be adjusted so the cables do not make contact with the leaf springs.
Re-install the driveshaft and double check all work.
Remove the included metal sleeves in the shock bushings and install the included shock spacers into both ends of the shocks (Figure 13).

Each shock will use four spacers per shock before installing them into the factory mounts reusing the factory hardware. Torque to 85 lb. ft.

HARDWARE KIT, REAR DROP KIT, 4-6″|
---|---
07-18 SILVERADO
DESCRIPTION| QTY/KIT| LOCATION
HEX HEAD BOLT, M14-2.0 X 110MM, CLASS 10.9 ZINC| 4| SHACKLE BOLT
NYLOCK NUT, M14-2.0, 16MM HT, CLASS 10, ZINC| 4| SHACKLE NUT
WASHER, M14, 28MM OD, ZINC| 8| SHACKLE WASHER
HEX HEAD BOLT, M10-1.5 X 25MM, CLASS 10.9, ZINC| 6| SHACKLE MOUNT BOLT
NYLOCK NUT, M10-1.5, CLASS 10, ZINC| 6| SHACKLE MOUNT NUT
WASHER, M10, 20MM OD, ZINC| 12| SHACKLE MOUNT WASHER
HEAD HEAD BOLT, M8-1.25 X 20MM, CLASS 8.8, ZINC| 2| BRAKE TAB BOLT
HEX NUT, M8-1.25, CLASS 8, ZINC| 2| BRAKE LINE NUT
WASHER, M8, 16MM OD, ZINC| 2| BRAKE LINE WASHER
SPLIT LOCK WASHER STANDARD, M8, ZINC| 2| BRAKE LINE LOCK WASHER

Rear Shock Valving Adjustments

Shocks with one adjuster knob:

Shocks with two adjuster knobs:

| | Compression| Rebound
---|---|---|---
Drag Racing:| 4-10 clicks| 7-12 clicks| 2-8 clicks
Nice ride and handling:| 0-6 clicks| 0-6 clicks| 2-8 clicks
Firm ride & improved handling:| 6-12 clicks| 6-12 clicks| 6-12 clicks
Aggressive handling:| 13-18 clicks| 13+ clicks| 14-18 clicks

Important Notice Regarding ADAS: This product may affect the operation of your vehicle’s ADAS, such as lane departure warning systems, automatic emergency braking systems, and adaptive cruise control systems. It is the responsibility of the installer to ensure that the ADAS systems are properly recalibrated after installation. Failure to do so may result in the ADAS systems not operating as intended and could potentially lead to a collision or other safety hazards. By purchasing and installing this product, you acknowledge and accept the risks associated with modifying your vehicle’s suspension and potentially affecting its ADAS systems.

Technical Support Line:952-985-5675 Email: sales@QA1.net

READ ALL INSTRUCTIONS CAREFULLY AND THOROUGHLY PRIOR TO STARTING INSTALLATION. PRODUCTS THAT HAVE BEEN INSTALLED ARE NOT ELIGIBLE FOR RETURN. USE THE PROPER JACKING LOCATIONS. DEATH OR SERIOUS INJURY CAN RESULT IF INSTRUCTIONS ARE NOT CORRECTLY FOLLOWED. A GOOD CHASSIS MANUAL, AVAILABLE AT YOUR LOCAL PARTS STORE, MAY ALSO AID IN YOUR INSTALLATION.

DISCLAIMER / WARRANTY

QA1 WARRANTS THAT THE PRODUCTS WILL BE FREE FROM DEFECTS IN MATERIAL AND WORKMANSHIP FOR ONE YEAR FROM DATE OF SALE TO THE ORIGINAL PURCHASER. QA1 MAKES NO OTHER WARRANTY OF ANY KIND, EXPRESS OR IMPLIED. QA1 SHALL HAVE NO OBLIGATION UNDER THE FOREGOING WARRANTY WHERE THE DEFECT IS THE RESULT OF IMPROPER OR ABNORMAL USE, YOUR NEGLIGENCE, VEHICLE ACCIDENT, IMPROPER OR INCORRECT INSTALLATION OR MAINTENANCE, NOR WHEN THE PRODUCT HAS BEEN REPAIRED OR ALTERED IN ANY WAY. QA1’S LIABILITY IN THE CASE OF DEFECTIVE PRODUCTS SUBJECT TO

THE FOREGOING WARRANTY SHALL BE LIMITED TO THE REPAIR OR REPLACEMENT, AT QA1’S OPTION, OF THE DEFECTIVE PRODUCTS. THE USER UNDERSTANDS AND RECOGNIZES THAT RACING PARTS, SPECIALIZED STREET ROD EQUIPMENT, AND ALL PARTS AND SERVICES SOLD BY QA1 ARE EXPOSED TO MANY AND VARIED CONDITIONS DUE TO THE MANNER IN WHICH THEY ARE INSTALLED AND USED. QA1 SHALL BEAR NO LIABILITY FOR ANY LOSS, DAMAGE OR INJURY, EITHER TO A PERSON OR TO PROPERTY, RESULTING FROM THE INSTALLATION, DIRECT OR INDIRECT USE OF ANY QA1 PRODUCTS OR INABILITY BY THE BUYER TO DETERMINE PROPER USE OR APPLICATION OF QA1 PRODUCTS. WITH THE EXCEPTION OF THE LIMITED LIABILITY WARRANTY SET FORTH ABOVE, QA1 SHALL NOT BE LIABLE FOR ANY CLAIMS, DEMANDS, INJURIES, DAMAGES, ACTIONS, OR CAUSES OF ACTIONWHATSOEVER TO BUYER ARISING OUT OF OR CONNECTED WITH THE USE OF ANY QA1 PRODUCTS. MOTORSPORTS ARE DANGEROUS; AS SUCH, NO WARRANTY OR REPRESENTATION IS MADE AS TO THE PRODUCT’S ABILITY TO PROTECT THE USER FROM INJURY OR DEATH. THE USER ASSUMES THAT RIS

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