Tuff Country 16730 - GM 88-91 1/2 ton Blazer / Sub 6 box kit User Manual
Page 3
 
3. Working on the driver side, disconnect the stock brake 
line at the frame mount. Let the stock brake line hang. 
Special Note: Brake fluid is going to leak out, it is a 
good idea to place a bucket under the vehicle to 
catch the brake fluid that will leak out. After the 
installation is complete, the brake lines will need to 
be bleed. Repeat procedure on the passenger side. 
See Illustration # 1
4. Working on the driver side of the vehicle, remove the 
stock sway bar from the stock frame mount. The stock 
hardware may be discarded. Let the stock sway bar 
hang. Special Note: If the vehicle that you are 
working on does not have a stock front sway bar, 
please discard this step. Repeat procedure on the 
passenger side.
5. Working on the driver side, remove the stock cotter pin 
and caster nut that connects the stock drag link ball joint 
to the stock steering arm. If you are not going to replace 
the stock steering arm with a raised steering arm, save 
the stock cotter pin and caster nut for later re-installation. 
Remove the stock drag link from the stock steering arm 
and let the stock drag link hang. Special Note: Tuff 
Country EZ-Ride Suspension highly recommends 
installing a raised steering arm once a 6” 
suspension system has been installed. If you have 
not already ordered your raised steering, please 
contact Tuff Country or your local Tuff Country 
dealer and order part # 70100.  
 
6. Place a pair of hydraulic floor jacks under the front 
axle. Place one hydraulic floor jack on the driver side and 
one on the passenger side. 
 
7. Working on the driver side, remove the stock U-bolts 
from the stock location. The stock U-bolts and hardware 
may be discarded. Repeat procedure on the passenger 
side. 
 
8. Carefully lower down on both hydraulic floor jacks at 
the same time approximately 6”. This will allow enough 
room for the new front springs to be installed into the 
stock location. 
 
9. Working on the driver side, remove the stock spring 
from the stock location. The stock front spring, stock 
front spring hanger hardware and stock front spring 
shackle hardware may be discarded. Repeat procedure 
on the passenger side. 
 
10. 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 the 
front eyelet bushings and sleeves a side for later re-
installation. The rear eyelet bushings and sleeves may 
be discarded. 
 
11. Locate the new polyurethane lube packs, (4) 
MO2360 spring eye bushings and (2) S10006 spring eye  
 
sleeves. Spread the new polyurethane over the new 
bushings 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. 
 
12. 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
 
13. 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. 
 
14. 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
15. 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
16. 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 # 5. 
 
17. Carefully remove both hydraulic floor jacks from 
under the front differential. 
 
18. 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.