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#1
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67-69 hood latch IQ
In order to help my fellow board members understand the difference in these latch's and what GM changed on them after the 67 model year here are pictures of each with an explanation. Over the past 5 or so years I have taken hundreds of these latch's apart in order to restore them.
This design hood latch was first used by Buick, Olds and Pontiac in 1963. There are many variations of it to fit different cars but basically they are all the same. The design was used by Buick and Olds thru 1972 and by Pontiac till 1981. All of these latch's have two steps for their complete release. There are two designs with the first being 63-67 and the second being 68-81 The 63-67 version... In order for this latch to release the lever at #5 is pulled out of the teeth in the main latch #4 by the release lever being pulled, this is the main latch and the first pop that you get. At this point the secondary or safety is still holding the hood closed. The second part of the pull releases the secondary or safety catch #3 . This is done by the heel of #5 pushing the safety into the latch body. At that time the hood is completely free of the latch. If the hood spring is strong and you pull the release fast enough the hood will seem to open with a single pull of the release but it is a two step process. In order for this latch to fail and fully release two things would need to happen. First the spring at #1 would need to fail and allow #5 to release from the main latch, but even with a broken spring it is HIGHLY unlikely that the lever would release as the upward movement of the hood actually puts more pressure on #5 against the main #4. Ok so lets say that it releases then the safety #3 would be the last line of defense and would catch the hood before it cleared the latch. In order for that to fail the spring at #2 would need to break. You can see that it is designed so that even if spring #2 were to break the weight of the safety catch keeps it in the extended position and in position to catch the hood. These GM engineers are some smart cookies that's for sure. All this doesn't mean it can't fail but I think it is highly unlikely. I can say that I have never seen a broken spring on one of these nor have I ever seen one fail. 1967 F Body ( missing a spring) In 1968 the latch had a redesign in which the safety part of it was changed. Is it a safer version? yes it is but that doesn't mean that the earlier version is unsafe after all it was used on millions of cars. Car makers are always looking for ways to improve on the existing product. All of the above applies to the 68-81 version so I will cover the redesign next. So GM engineers added the flag part to the safety catch #3 and also redesigned the receiver that is in the hood ( that's why you can't use the 68 and up on a 67 hood). Its propose is to physically force the safety catch closed. This is done by the redesigned receiver in the hood hitting it and forcing it to catch the hood. 1968-1969 F Body ( a 68 latch is a 69 with a 67 lever) The design was used on GM cars for 18 years so I am pretty certain that it is fool proof. Off course there are exceptions to every rule but like I said earlier I have NEVER seen either design fail. |
#2
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Excellent post, Norwood!
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John Wallace - johnta1 Pontiac Power RULES !!! www.wallaceracing.com Winner of Top Class at Pontiac Nationals, 2004 Cordova Winner of Quick 16 At Ames 2004 Pontiac Tripower Nats KRE's MR-1 - 1st 5 second Pontiac block ever! "Every man has a right to his own opinion, but no man has a right to be wrong in his facts." "People demand freedom of speech to make up for the freedom of thought which they avoid." – Socrates |
#3
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Good info. Keep learning new stuff each day ...
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67 Firebird Convert 455 +.060 TH400 74cc KRE d-ports piston dished 16cc H-beam rods Comp Cam 305-AH-8 cam 108* LSA 253/260 @.050 duration .577/.594 lift w/1.65 rockers Ford 9" 3.50 Detroit Locker M/T Sportsman Radials 31x18x15 on Convo Pro 15x15s |
#4
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How do the receivers differ?
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