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Rusty Tailgate Hinge Repair

Tech Article

  1. Mudzer
    Article/photo's courtesy of:
    Neil Pickett
    Rusty Tailgate Hinge Repair
    The '73-'91 Blazer/Jimmy is, in my book, one of the best off-road vehicles - bar none. However they are prone to rust if you live in areas where salt and brine are used to keep roads clear in winter months. I opened my tailgate one day and found it would not shut quite right afterwards. After some brainstorming, My Father and I devised this brace to replace the rear hinge mounting area on my 1978 K5 Blazer. After getting much attention from the 'Boards we decided to make this a tech tip.

    I started out by removing the rusted areas. You may want to record some measurements before hacking away at your Blazer. The section I removed from the bed floor was approximately 2" from the edge of the floor pan. Be careful not to disturb the body mounts at this time. You will notice when removing the bed floor, there is a thick piece of metal under there, that is the body mounting points. I removed 2" (from rear edge) of this also, see fig 3. I then started with a piece if 2"x2" 1/4" wall square tubing and cut it the width of the frame. The piece that goes in place where you removed part of the body mount is where the 2"x2" tubing goes. The outer portions of this brace is made if 2"x3" 1/4" wall tubing. I used this because of the hinge mounting points being approximately 3" long. The 2"x3" tubing was beveled on the outside to clear existing body bolts which are located under the bedside pillar.

    After measuring for an overall length (I made mine long enough to support under the bedside pillars), I cut and welded the pieces together, see fig 1 and 2. Next I test fitted the piece and trimmed any excess floor pan and body mount. Be sure to make the piece a tight fit to the existing sheet metal so you do not have to fill large gaps when welding.

    While test fitting I marked the hinge mounting holes onto the brace. It was then, I noticed I would have to fab some shims approximately 3/8" thick to make the tailgate hinges mount correctly (factory alignment) see fig 1. I believe I planned to use 3/8" bolts so I located the proper drill bit and tap & die set. I drilled out the existing hinges (they are threaded so make them a little oversize) and drilled and tapped the brace (8 holes total). I then drilled my shim plates with same size as I did the hinges (a little bigger than 3/8"). You then can place the brace back into place.

    The way mine went in is I had to slightly raise each bedside (they may sag somewhat when removing rusty parts) then put in the brace. I again lined up the brace and test fitted the tailgate. After careful aligning, I tack welded the brace to the body mount. I tested the hinge shims and put in all the bolts and tightened it down. It shut so great!!!!! I then welded the brace to the bedside pillars and everywhere were the low spots in the corrugated bed pan contacted the brace.

    I then seam sealed the brace and bed pan. Remove tailgate and install the Tail Pan - ordered from LMC truck part # 38-7980. This part is not that great and it required much trimming. After re-installing the tailgate I spot welded the part onto the back of the brace (in the factory location). By the way did I mention the Blazer tailgate weighs a ton!!!! Buy some replacement sheetmetal (corrugated like factory) to patch over the brace and paint to your desired color.

    This job took me about 4 hours from start (thinking the idea up) to finish. I would recommend keeping your hard top in place to help keep the bedsides lined up. The brace may be built using 2"x2" tubing and possibly 3 1/2"x2 1/2" for the outer portions to eliminate the 3/8" thick plate shim. This would require some precise measurements to insure a proper fit of the tailgate hinges. This brace worked for me and made my Blazer about 100% stronger in the rear tailgate area. My tailgate shuts with ease and my bedsides are stiffer. With all custom fabrication, remember this is "Custom", meaning not all Blazer/Jimmy's are the exact same dimensions. Be sure to measure, re-check, and re-check again. Good luck.

    rearview.gif
    Rear View (fig. 1)

    bottomview.gif
    Bottom View (fig. 2)

    sideview.gif
    Side View (fig. 3)

    closeupsideview.gif
    Close Up Side View (fig. 4)

    This brace worked for me and made my Blazer about 100% stronger in the rear tailgate area.​