Bolt-in Steering Box Brace Kit and Weld-in Frame Repair kit.

The straight axle GM trucks are notorious for frame cracks in the steering box mounting area.  This kit is designed to prevent that problem by eliminating the frame flex caused by increased steering loads like lifts, big tires and off-road use.  The bolt-on (OK you do have to drill one hole) brackets triangulate the mounting area to stiffen it up before it breaks.  If the frame is already broken, you will need a weld-on repair kit before you install the brace. 

For hard use applications, we recommend using both the weld in kit and the bolt in Brace Kit, especially in 1/2T trucks and Blazers. "Hard use" could be defined as 37" and up tires in rock crawling or other demanding use. The GU39001-E kit is shown here.  See Application List below.

      Reviews of the ORD steering box brace and weld in repair kit are online at www.coloradoK5.com.

Part No.

Application Price



Fits ’68 to ’72 GM Fullsize 4WD Trucks*
**This product has special fitment requirements, click here to make sure it will work for you**

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GU39001-2WD Fits '73 to '87 ('91) GM Fullsize 2WD Trucks $115

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Fits ’73 to ’80 GM Fullsize 4WD Trucks* $130

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Fits ’81 to ’87 (’91) GM Fullsize 4WD Trucks* $130

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Weld on repair kit: GU39002

Fits ’73 to ‘87(’91) GM Fullsize 4WD Trucks $79

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*Steering box brace is based on the frame of the truck, not the actual steering box

Here's a shot of the GU39002 weld in repair kit. It's contoured to fit the frame rail where the steering box mounts to reinforce it against cracking, or to repair damage that's already been done. Welding is required for installation.

Tech Notes:

  • Requires drilling one hole in the front crossmember, otherwise, this kit bolts on. Shown below are pictures of the GU39001-L kit installed on an '89 K5 Blazer:

          The main brace is shown above, the smaller brace is shown installed below.

  • The only difference between the "-L" and "-E" kits is the small clip that goes in front of the crossmember. Here's a photo of the '81-87 ('91) brace kit:


    Here's a shot of the 'pre-73 box brace kit:

    Here's the '73-'87 ('91) Chevy 2WD box brace kit:


  • The heavier duty trucks, ¾ ton and larger, have frames made of thicker material than the ½ tons and Blazers but this is not enough to prevent steering cracks. Large tires and even street or mild off-road driving can eventually crack the frames out. It’s much easier to prevent breakage now by installing the bolt in brace kit than it is to fix it later.


  • Later model trucks have a factory clip in front of the crossmember which can be retained with our brace, the small front clip just goes under it.


Notes on the 67-72 bolt-in steering box brace:

'72 and older with big block motor in the factory big block position may have interference between the crank pulley and box brace, you need approximately 3" from the crossmember to the pulley for the brace to fit.

There are several variations in the frame construction and in the front crossmember on the 67-72 Chevy trucks.  Our kit was designed around the frames that had an extra piece of metal riveted to the inside of the frame, like this:

If your frame does not have that extra piece of metal on the inside of the frame, our brace will work but you'll have to use spacers/washers:

There are two versions of the 67-72 crossmember at the front of the frame.  If you have this version, where the crossmember curves back towards the rear of the truck, our brace will work:

If you have this version, where the crossmember is straight, our brace will not work without modification:

Choose the category you would like more information on.

Doubler™ Dual Transfer Case
Swaybar Correction/Disconnect™ Kit
Shackle Flip™ Kit for ‘67-up GM trucks
Bolt-In Steering Box Brace Kit
1" Body Lift Kit
Competition Style Motor Mounts
Heavy Duty Front Shackles
Chrome Moly Front Axle Shafts
Drivetrain Upgrades
Blazer Soft Tops

Greasable Rear Suspension Bushings
Swaybar Bushing Kits
Body Mounts
Transfer case mounts
Spring Bushings
Competition Style Bumpstops
Bushing Assemblies
Tuff Country Suspension
Coming Soon...