SBGK Steering Box Gusset Kit Instructions
Those of you that have '73 to '87 Chevy or GMC full-size pickups or up to 1992 Blazers and Suburbans, are probably fully aware of the steering box problems these rigs typically have. It's not the box itself but the way it is mounted to the frame lends itself to major flexing caused by bigger tires, wheels, and especially lockers.
The frame rail can crack and loosen the bolts, and then the box falls off at the most inopportune time. The 4wd company offers a band-aid type frame repair kit and using it is not recommended or needed because it spaces the box out for the thickness of the repair, and does not attack the flexing problem itself. Also, the holes in the repair band-aid are large and not accurate. Welding the repair band-aid on creates another problem with too much weld on the side of the mounting area which can lead to stress cracks next to the weld area.
This is a good example of too much weld not being the good thing. Autofab SBGK brackets go to the source of the problem and triangulate the mounting of the steering box to the front cross-member to effectively stop the flexing which causes the frame to crack in the first place! If the repairs are done properly and the SBGK kit is installed correctly you will not have any problems in the future. If you have any questions or problems with your repair please call Autofab for good practical advice BEFORE you start welding. A few questions and the right advice will save you much grief.
The brace kit consists of a long brace that attaches to the inner frame rail with new grade 8 bolts that go through the bracket and thread into the steering box. The other end of the bracket attaches to the center of the front cross-member after a hole is drilled. NOTE! 82 and newer vehicles have a factory corner bracket. Our smaller bracket will bolt in behind it using original hardware. Some filing of the bumper brace holes may be necessary to bolt the corner bracket back into place. On 73 to 81 models an existing 5/8 hole is used to mount the smaller bracket to the cross-member with a 5/8 bolt and locknut.
Behind the cross-member and on the frame rail are numerous brake and fuel lines. The 5/8 bolt has a line behind it but can be pulled down slightly to move it out of the way. The large Autofab bracket clears the proportioning valve and has cutouts to clear the other lines, but verify on installation that none of the lines will be pinched accidentally by either bracket! The two inner frame rail bolts are fairly easy to remove, but sometimes the power steering hoses will need to be moved slightly for clearance of the wrenches. Normal installation should only take about 1 1/2 hours with standard hand tools and a drill. With the two rearward bolts removed, insert the two new bolts supplied by the bracket bosses and if the bolts are long enough, the stock washers as well. Place the brace in position and thread the new bolts through the gussets bosses, then the frame, and into the steering box.
Look on the outside of the steering box and verify that the bolts go all the way into the threads on the box for security. If they are the correct length, remove them and coat the threads with red locktite and reinstall them, to ensure that they won't work loose during service. Note: it is a good idea to periodically check these. DO IT! The one problem area we found was the frame fix kit previously installed on the well-tweaked frame. The plate was installed and welded to the frame which moved the steering box outward by a 1/4". This resulted in the new bolts provided being to short. We bought new bolts a 1/2" longer and fit them to get the correct length.
Make sure you buy Grade 8 or stronger bolts! After the long bracket is secured to the frame, a hole is drilled into the cross-member for the other end of the bracket to be bolted to. An existing hole used for a small clamp is drilled out to 1/2” from the front with a regular drill. The bracket is then secured to the cross-member with the bolt and locknut provided. Depending on the condition and tweakage of your frame the end of the bracket may not line up perfectly with the small hole, and any brake or fuel lines should be moved to the drilling process or the bracket won't harm the lines.
Once installed the steering box gusset will strengthen the frame and box mounting location. Notice how the steel lines run behind the bracket through a notch. Autofab even offers a kit for the two-wheel drive trucks that accomplishes the same strengthening as the 4X4 model. For 2wd trucks the steering box gusset brace bolts to the front side of the cross-member below the radiator. It will bolt to the first 2 holes of the gearbox.
You will need to drill the cross-member out to 5/8 inch for the big bolt. Start the gearbox bolts first then snug them up to locate the 5/8 hole. Sometimes there is frame misalignment and the gusset will not sit flat on the cross-member. Use washers behind the gusset if this is the problem. It is better to have the bracket relaxed as you tighten it up to the gearbox. We have two additional recommendations for you.
The first is; you should drill out the rivets in the front cross member and replace them with Grade 8 bolts. Rivets loosen up with age and stress and allow the frame to move. Torquing the bolts will eliminate this problem. The other solution is to replace your motor mounts with our competition style motor mounts. They are made with a urethane bushing assembly and are much stronger than stock. By design when bolted together you are, in effect, making your engine a cross-member and your frame even stronger. Also you mechanic types will appreciate getting to the bolts easier as they are more open.
These mounts have been used extensively in offroad racing and they Work! Also, they are made from a softer compound urethane so engine vibrations will not be noticed as in solid type drag racing motor mounts. These old design Chevy frames can use all the help they can get in this general area and if your truck is important to you please consider these recommendations.
10996 NORTH WOODSIDE AVE. SANTEE CALIFORNIA 92071 619/562-1740 FAX 619/562-6151