Tuff Country 14721 - GM 73-87 3/4 ton 4 box kit (systems with rear springs) - Manual (Page 4)

on the passenger side.
9. Locate the new front leaf springs. Working on the front
and rear eyelet’s of the front springs, remove the new
sleeves and bushings from each end and set a side for
later re-installation.
10. Locate the new polyurethane lube packs. Spread the
new polyurethane over the new bushings that were
removed from step # 9 and re-install them back into the
new front spring assembly. Make sure to re-install the
new sleeves. Special Note: Make sure to use the new
polyurethane lube packs prior to inserting the new
bushings back into the new front springs. This will
increase the life of the bushing, prevent squeaking
and help with ride quality.
11. Locate the new front spring eye hardware. Working
on the driver side, install the new front spring into the
stock location and secure using the new spring eye
hardware. Make sure to use thread locker or locktite
on these bolts. Torque the front spring eye hanger
hardware to 120 ft lbs. Special Note: Do not torque
the front spring eye shackle hardware at this time.
Once the vehicle is lowered to the ground, the front
spring eye shackle will be torque to 40 ft lbs. Repeat
procedure on the passenger side.
See Illustration # 2 / Front Spring Hanger
See Illustration # 3 / Front Spring Shackle
12. Carefully raise up on both hydraulic floor jacks at the
same time until the newly installed front springs seat
properly to the stock front spring perches.
13. Locate (2) new 5/8” x 3” x 7 5/8” Round U-bolts, (4)
5/8” U-bolt High Nuts and (4) 5/8” U-bolt Washers.
Working on the driver side, install the new U-bolts into
the stock location and secure using the new U-bolt high
nuts and washers. Torque to 130 ft lbs.
See Illustration # 4
14. Locate (1) new 5/8” x 3” x 7 5/8” Round U-bolt, (1)
new 5/8” x 3 1/2” x 9 5/8” Round U-bolt, (4) 5/8” U-bolt
High Nuts and (4) 5/8” U-bolt Washers. Working on the
passenger side, install the new 5/8” x 3 1/2” x 9 5/8”
round U-bolt into the stock location around the stock
front differential inside location. Secure using the new U-
bolt high nuts and washers. Secure the new 5/8” x 3” x 7
5/8” round U-bolt into the stock outside location. Secure
using the new U-bolt high nuts and washers. Torque to
130 ft lbs.
See Illustration # 5
15. Working on the driver side, re-install the stock drag
link back into the stock steering arm. Secure using the
stock caster nut and cotter pin that was removed from
step # 4. Special Note: If you are installing a 2” or 3”
suspension system, you may skip this step.
16. Carefully remove both hydraulic floor jacks from
under the front differential.
17. Locate (2) larger brake line relocation brackets, (2)
5/16” x 1” bolts, (4) 5/16” flat washers and (2) 5/16”
unitorque nuts. Working on the driver side, secure the
new brake line extending bracket to the stock location
and secure using the new 5/16” x 1” bolt and hardware.
Torque to 18 ft lbs. Make sure to use thread locker or
locktite on these bolts. Repeat procedure on the
passenger side.
18. Working on the driver side, move the stock hard
brake line located in the inner part of the frame rail under
the stock frame. Reconnect the hard line and the soft line
back together around the new brake line extending
bracket that was installed in step # 17. Repeat procedure
on the passenger side.
See Illustration # 6
19. Working on the driver side, install the new front
shocks absorbers using the stock hardware removed
from step # 2 . Special Note: Shocks are not included
with this suspension system, shocks need to be
ordered as a separate part number, Tuff Country
recommends using a 20” fully extended nitrogen gas
shock when installing a 2” suspension system and a
23” fully extended nitrogen gas shock when
installing a 3” or 4” suspension system. If the
vehicle that you are working on has the dual shock
option, Tuff Country recommends using a 23” fully
extended cellular gas shock for the auxiliary shock
when installing a 2” suspension system and a 26”
fully extended cellular gas shock for the auxiliary
shock when installing a 3” or 4” suspension system.
Repeat procedure on passenger side.
See Illustration # 6
20. Install the tires and wheels and carefully lower the
vehicle to the ground.
21. With the weight of the vehicle on the ground, torque
the top and bottom spring eye shackle bolts on the driver
and passenger side to 40 ft lbs.
Front End Installation Complete
Rear End Installation
22. To begin installation, block the front tires of the
vehicle so that the vehicle is stable and can’t roll forward.
Safely lift the rear of the vehicle and support the frame
with a pair of jack stands. Place a jack stand on both the
driver and passenger side. Next remove the wheels and
tires from both sides.
23. Locate (1) rear brake line extending bracket, (1)
5/16” x 1” bolt, (2) 5/16” flat washers, (1) 5/16” unitorque
nut and (1) 5/16” lock washer. Remove the stock brake
line bracket from the rear differential and save stock bolt
for later re-installation. Secure the new brake line bracket