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Need info on rear seat mounting and lap belts

Discussion in '1969-1972 K5 Blazer | Truck | Suburban' started by homemadesin, Sep 12, 2002.

  1. homemadesin

    homemadesin 1/2 ton status

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    I just got the '72 and it had a "non-original" back seat that hasn't been mounted in quite some time. I don't have the hold down bolts, the lap belts or anything. Just a brown seat for my black interior.

    The LMC book has been ordered, but another week or two off I guess. Can anyone give the bolt specs and suggest where I can get the lap belts (that work!)? Should I go diggin' at the Junkyard?
     
  2. chevyracing

    chevyracing 1/2 ton status

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    It uses bolts and clamps. After I have my coffee I will go look and see what mine has. The lap belts I have on mine are bolted to the seat frame, poor design........ I would consider mounting them through the floor if I were you.

    John
     
  3. Greg72

    Greg72 "Might As Well..." Staff Member Super Moderator

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    Troy,

    The "original" seat used a total of 4 bolts across the back of the seat to anchor to the floor. If you pull the carpet back you will see 4 re-inforcement plates approximately lined up with the wheel tubs. Each one has a welded nut on the underside of the cab that a bolt goes into. The stock seat has 4 angled brackets that sit over these plates and bolt down.

    In the front of the seat there are only 2 bolt holes total, one on each side. The seat frame is made out of round tube and there is a bracket shaped like a "question mark" (?) that curls around that tube and provides a flat area with a hole to put the bolt through.....easier to understand in person, than to describe!

    As far as the seatbelts....my stock seat has 3 sets of belts that are bolted to those rear mounting brackets. They are standard GM lap belts. I have no particular concerns about this factory mounting location vs. a floor mount. I think that's a matter of personal preference or opinion. /forums/images/icons/smile.gif

    Hope that helps. Are you going to start looking for a black 'factory' seat to replace that brown one?
     
  4. TONYP

    TONYP 1/2 ton status

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    Troy,
    I just mounted my back seat, I had to make up the front bracket to hold the seat down, I re-tap the holes to clean out the years of crud in them, the back are 1/2"-13 holes and the front are 7/16"-14 holes. My front holes were rusted so I drilled and tap them out to 1/2"-13 holes.
    If your putting hole through your carpet for the screws, I found a little trick not to run the loops in the carpet....I heated up a screw with a small tourch then kind of melted the carpet away form the hole, You then have a clean hole with no loose threads to wind around the screw.
    Good luck!
     
  5. Blazer1970

    Blazer1970 1/2 ton status

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    Pretty sure the holes were originally 1/2-20 fine thread.
     
  6. TONYP

    TONYP 1/2 ton status

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    your right, the org. size was 1/2-20 bolt.I had to tap mine out larger to get clean threads. /forums/images/icons/confused.gif
     
  7. homemadesin

    homemadesin 1/2 ton status

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    Its the damnedest thing....I took a look under the Blazer today and there are only three mounting locations for the rear seat. I'm not kidding! I took a look on the top side too (or felt under the carpet rather) and there was no hole on the passenger rear side corresponding to where the driver rear side hole was. Is that messed up or what?

    I think I'll just modify the seat to be like the Jeep rear if possible. for some reason there it a hole in the center of the bed, about where the back of the rear bench would be. I could land the seat belts there I guess. What's weird is that the car had the rear seat as original. What am I missing?
     
  8. TONYP

    TONYP 1/2 ton status

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    do you think someone replaced a pannel?
    you should see (if they haven't fell off) a thin like nut thing, like a cap for the screw to keep it clean. Mine had them where the screw would come through the bed, they were pinched on the nut that was welded to the bed....
     
  9. homemadesin

    homemadesin 1/2 ton status

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    I'm starting to think that the panel was replaced. I can't imagine a car from the factory with back seat having only 3 bolt locations. Also, the 3 nuts on the underside look the same size, but are not 1/2-20. I have a 1/2-20 bolt and couldn't even get thread to thread, so I'm thinking it is actually 7/16-20. It definately looks like fine thread. As of yet, I can't find a source for the bolts. LMC didn't have any helpful description on the bucket seat hold down bolts, but Idon't think they are the same.
     
  10. bouncytruck

    bouncytruck 1/2 ton status

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    Pick up a Factory Assembly Manual. They're pretty useful for things like this. Unfortunatly, they don't say what size bolts or label things too well, but the illustrations are useful.

    I just bought a seat from Kilomonjaro and it only had two rear mounting brackets. He said that he has seen them with two and four rear brackets before. My truck has four spots and so did my '72. Consistancy wasn't high on Chevy's list when they were building them, so maybe, for some strange reason, yours really did only have three. You could run with only two rear brackets.
     
  11. bouncytruck

    bouncytruck 1/2 ton status

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    This was Kilomanjaro's response to me when I asked him how to bolt the seat belts up with only two brakets

    ...on the way to bolt up the seat belts. There were two different styles of seat belts for the rear seat of blazers, the kind that just had two mounting brackets on the back had just one really long belt that stretched across the entire seat, so it only had one buckle. The other style which i am guessing you have is the one that has 3 individual seat belts for the rear. there are 4 places to bolt them down on the 4 brackets that stretch across the back. there is no rhyme or reason for which blazer got what, it is not designated on the buildsheet and it was not part of the CST package because i have has CST's with both syles. Just one of those funny little differences.
     
  12. Ressurection

    Ressurection 1/2 ton status

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    Troy,
    ****WORD OF CAUTION!!!!!**** For safety purposes the anchor nuts under the rear of the back seat are all welded to a THICK STEEL BAR that is in turn welded to the UNDERSIDE of the floor. DO NOT simply use small washers, etc. 'cause in case of an accident the back seat could probably rip right out. I searched high and low and finally found a '72 carcass to cut these components out of. If I can get my hands on a dig. cam I'll send pics if you want. Also, the seatbelts should come with the seat. Good luck!
     
  13. TONYP

    TONYP 1/2 ton status

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    Ok, when you say 3 holes only on the back side of the back seat...are they on the outside or do you have one on the outside and two in the middle? Now remember that there are holes for the spare tire back there too. /forums/images/graemlins/k5.gif
     
  14. homemadesin

    homemadesin 1/2 ton status

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    Thanks for the info. I tried to line up the holes in the seat feet, but they don't! This seat just doesn't belong in this vehicle. I can see three bolts/chanel welded to the underside of the bed, but they are about 2" in from the fender wells and and each end - nowhere near the seat holes. I guess I'm gonna have to look at another Blazer to figure this out....
     
  15. TONYP

    TONYP 1/2 ton status

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    Ok, just looked it up in the book...It says "Optional Rear Seat" your truck must of be a 2 seater /forums/images/graemlins/k5.gif
     
  16. homemadesin

    homemadesin 1/2 ton status

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    That's just it though, check out the original manifest... [​IMG]
    It clearly shows rear seat. I got the engine & tranny back in my project car ('74 914) so I can move it and park the Blazer in the garage to some serious looking. That's the only way to figure this out.
     
  17. bouncytruck

    bouncytruck 1/2 ton status

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    here is a photo that I found of a back seat. This is how the four rear mounting points on the seat should look.

    [​IMG]
     
  18. homemadesin

    homemadesin 1/2 ton status

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    Wow, 4 rear mounting points. The seat I have only has two, which have the same spacing as the two outer ones in your photo.

    I plan to pull the top off this weekend when I get the truck in the garage. Then I'll remove the rollbar and carpet to get a good look. Can you give me a distance from the rear of the bed to the rear mounting locations?
     

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