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68 - 73 rear bumper mounting

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Old Oct 27, 2007 | 03:58 PM
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Default 68 - 73 rear bumper mounting

Does the outside bumper bolt, that bolts through the quarter panel, do anything?

I removed my bumpers and took them to be replated. On the rear bumper, it looks to me like the only thing that the outer bolt does is break the quarter panel fiberglass.



I don't see any brackets or reinforcements behind it.



Has anybody left this bolt off? Will it matter?

I'm thinking that I should not replace it if it doesn't really hold anything?

Dave
Old Oct 27, 2007 | 05:59 PM
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It doesn't have any bracket, so just barely tight enough to keep it from falling off while you drive. Mine are 'finger tight'.
Regards
Alan
Old Oct 27, 2007 | 06:12 PM
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Sure should have a bracket. Mine is a rod about 1/4 inch in diameter that goes from the frame to the bolt. There is defintly some support that should be there.

If you have an assembly manual you can see it.
Old Oct 27, 2007 | 06:18 PM
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Originally Posted by Alan 71
It doesn't have any bracket, so just barely tight enough to keep it from falling off while you drive. Mine are 'finger tight'.
Regards
Alan
So, then why put it in at all?

Dave
Old Oct 27, 2007 | 08:40 PM
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Default Horrible Weak Spot

We just repaired a 64 and a 68. Both had damage in this area. We reinforced each side with metal inside and out and fiber-glassed them in. We fabricated exact shape metal cups to cover the area and then glassed them in. Actually the whole rear bumper set up is the same type. Bumpers through glass. We went across the whole rear with the 64 and made it stronger with the steel glassed in. The 68 didn`t need as complicated repair as the 64.
Old Oct 27, 2007 | 09:17 PM
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On original cars their was a rubber spacer in the hole that may have helped them not break out on 73's
Old Oct 27, 2007 | 09:21 PM
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Originally Posted by Gordonm
Sure should have a bracket. Mine is a rod about 1/4 inch in diameter that goes from the frame to the bolt.
But the rod is for the inner bolt on the bumper. The outter is a "Bracket"
See pic
Old Oct 27, 2007 | 09:34 PM
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Originally Posted by Jclgodale3
But the rod is for the inner bolt on the bumper. The outter is a "Bracket"
See pic
I don't know what year that picture is from but my 72 assembly manual shows a rod going to the outside bolt. That is different than my setup. I have a rod going from the frame to the outer bolt. I also have a rod going to the inner bolt on the bumper also.

The assembly also does show what they call a bushing I assume it is rubber between the bumper and the fiberglass body, but the bolt comes from the inside through the rod bracket and bolts into the bumper.

Interesting, I also have a 69 assembly manual and it does not show the rod bracket I have in my 72. There must be a change somewhere between 69 and 72.

Last edited by Gordonm; Oct 27, 2007 at 09:39 PM.
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Old Oct 27, 2007 | 09:39 PM
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Originally Posted by Gordonm
I don't know what year that picture is from but my 72 assembly manual shows a rod going to the outside bolt. That is different than my setup. I have a rod going from the frame to the outer bolt. I also have a rod going to the inner bolt on the bumper also.

The assembly also does show what they call a bushing I assume it is rubber between the bumper and the fiberglass body, but the bolt comes from the inside through the rod bracket and bolts into the bumper.
it's from a 71 assembly manual. I'm fairly sure 68-72's were close to the same. Not sure why they would change from 71 to 72 but who knows. When shopping for one, they state "68-72 outter bumper bracket"
edit...I see now that there is "NO" bracket or rod. The bracket goes to the outter "REAR" not outter "SIDE" Only the bushing, rigid I'm sure, would go where he shows his damage

Last edited by Jclgodale3; Oct 27, 2007 at 09:43 PM.
Old Oct 27, 2007 | 09:44 PM
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I do also have the outer bumper bracket but there is also a rod that goes from the frame out. Maybe it was from 72-73

Here is a scan of the 72 manual. Hope you can see this.


Last edited by Gordonm; Oct 27, 2007 at 09:51 PM.
Old Oct 27, 2007 | 09:56 PM
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Originally Posted by Gordonm
I do also have the outer bumper bracket but there is also a rod that goes from the frame out. Maybe it was from 72-73

Here is a scan of the 72 manual. Hope you can see this.



Yup. See it clearly...Who the heck knows. They had to have fired the 68 engineers after that fiasco Maybe they fired em each and every year

Last edited by Jclgodale3; Oct 27, 2007 at 09:58 PM.
Old Oct 27, 2007 | 09:59 PM
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Originally Posted by Jclgodale3
Yup. See it clearly...Who the heck knows. They had to have fired the 68 engineers after that fiasco Maybe they fired em each and every year
I just figure they had a lot of broken fiberglass from minor bumps with no support. Who knows?
Old Oct 27, 2007 | 10:19 PM
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The hole in the fiberglass is about 3/4'' and the bolts are 7/16 so their is a little give but not much before the glass breaks. Any little tap broke the fiberglass. I would say the bumpers were for show only no 5mph.
Old Oct 28, 2007 | 04:33 PM
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No bracket on 71 #6589. The original round washer at the bolt's head breaks out the fiberglass just as your picture shows. I flattened out the bottom of the washer with a grinder so it fits up agaist the inner side of fiberglass in a less dangerous way. FINGER TIGHT!!!!
Regards,
Alan
Old Oct 28, 2007 | 05:22 PM
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Must be a 72 and up design with the bracket. Mine is a very early 72 #185 built in August of 71.
Old Oct 29, 2007 | 01:16 AM
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crazy inconsistent yearly decisions by the GM boys I guess
Old Oct 29, 2007 | 11:05 AM
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Originally Posted by Gordonm
I do also have the outer bumper bracket but there is also a rod that goes from the frame out. Maybe it was from 72-73

Here is a scan of the 72 manual. Hope you can see this.


Has anyone actually seen part # 22 (Bushing # 6263571) in this scan? If so what was it made from (rubber, plastic, steel)?
Thanks

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Old Oct 29, 2007 | 05:36 PM
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Look at the date of the revision...1-26-71..., you'd think #22 would be on some later 71s. The way the bushing is drawn (notice the dots) ,
I'd think it was a material other than metal. Nylon?
There is a spacer similar to that on the front bumper guard lower bolt, but a different part # and it's metal.
I'm actually no help, just wacko.
Regards,
Alan
Old Oct 29, 2007 | 06:30 PM
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The original's were rubber outside a metal sleeve or liner as I recall. I use a rubber hose I found that was the same size and cut it the length as needed.
Old Oct 30, 2007 | 07:07 PM
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Went to garage to look at my car. My 73 convert has the outer metal support rod shown in the illustration (Part No. 19). The bushing (part No. 22)appears to be the type Lyle refers to--rubber with a metal inner sleeve--but it is difficult to see.



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