Did 67 front bumper brackets use serrated washers on rear bolt?

[Mike S]

 Would one of you '67 owners be so kind as to check your chassis mounted front bumper brackets and let me know if you have the serrated washers on the rear bolt? I installed the front bumper (AMD '67 only front....fits perfect) and I followed the AIM. I noticed this morning I had two serrated washers left over. I looked at the '67 LOS survivor and it uses 4 washers total (2 front and 2 rear of the brackets) but the AIM clearly shows only the front bolts get it. When I refinished the brackets I smoothed the tooth marks but that was almost 2 years ago and honestly I don't remember if the rear holes had marks. I know LOS did things slightly different but I have a feeling this is one of those few AIM mistakes.
  Oh.....the rear J-nut on the bracket (AIM item #1) is now sold by AMK but is listed as a GTO item though using the same GM number.
The shape of the captive nut is slightly rounder compared to an original.

Thank You,
Mike

[x77-69z28]

Mike, let me dig out the restoration pics of my car. I will let you know.
Buddy

[Mike S]

Hi Buddy,

     I appreciate it. I see the washers are in the '68 AIM so I have a feeling it was used in the '67 model run at some point and the documentation updated later. The fact that I have 2 left over makes me wonder if they were originally on there, or they are extras I took from my 'bolt box' for which I usually take several fasteners from to phosphate and have on hand in case I need them.

Mike

[Petes L48]

I take it you have the later style sub frame, with the round holes on the inner sides horns, and doesn't use item #1 nut assembly as shown in the AIM sheet above?

[Mike S]

Hi Pete,

  I have the round hole in the front end of the frame rail and it does have the square cutout and slight indentation for the J-nut at the rear bolt. I removed one original J-nut and the other rotted so I replaced it with the AMK J-nut.

Mike

[x77-69z28]

Mike, I just went through all my pics. I don't have one pic with the brackets back on! I sold the car to a friend of 40+ years. Let me see where he has it stored and will take a look. I'm thinking they were not used on the rear bolt. There should be marks on the brkt from the serrated washer I would think?
Buddy

[Mike S]

Hi Buddy,
  The funny thing is.....when I stripped the bracket I filled in the washer scars with lead and sanded them smooth. It's been a while now and I don't remember if the rear portion of the bracket had any markings. I guess I could take a bracket off and strip the epoxy on that area.

Thanks!
Mike

[69Z28-RS]

Mike,

Is there some (any?) *reason* you are aware of that the front bolts would get the friction washer and the rear ones wouldn't ...?

[Mike S]

Hi Gary,
   No. I was going by the '67 AIM when assembling the car. The AIM doesn't list rear ones, but in '68 it does. Either the AIM is completely wrong or the rear washers were put into production somewhere in the 67 run and the AIM not updated. Just speculation at this point. The '67 LOS has them so that's sort of the wrench in the works.

Mike

[Sauron327]

67 LOS 11B. Serrated only on front. Original brackets with no teeth marks on the rear.

[Mike S]

67 LOS 11B. Serrated only on front. Original brackets with no teeth marks on the rear.

  Interesting.....my 67 04B LOS has serrated on front and rear bolts and also the later design chassis with the large front hole Pete was referring to. I wonder if originally one washer was used and field reports showed another was needed? Maybe customer complaints of the bumper position changing when using the jack, so the second washer was a fix?

Mike

[Petes L48]

Maybe the washer under the rear bolt was changed from lock to serrated when they did away with the j-nut?  Odd there are no revisions shown in the AIM for that change.  But I think someone said the AIM version we all use today may be missing all the updated pages that would have been present at the end of the model year. 

[Mike S]

 After reading what Pete mentioned about chassis sure got me thinking.
So I dug into this more and found:

• A CRG article about chassis changes: http://www.camaros.org/TopicsofResearch.shtml#1967Topics
• Looking at the unrestored 04B LOS coupe and found no J-nut, instead was using a bolt, nut and serrated washers on both sides, making it 2 washers per bolt.
• Looking at the 05B NOR convertible where the J-nut resides there is a large square cutout and stamped recess for the nut to mount through. This square cutout and recess is not on the 04B LOS chassis.

Both chassis on my cars have only 2 holes in the frame top near the 'horns'. The CRG article shows 2 top holes for early and 3 holes for late chassis with the latter having the large hole punched into the side 'horn'. So this is looking like Chevy used different style chassis from inventory that got the large round hole punched into it. I can see the LOS chassis needing the larger access hole for securing the separate nuts and washers during assembly, but the later production run 05B convertible, with what should be an earlier style chassis as evident by a square opening and recess for the captive J-nut, also has the large hole punched though not really needed when using the J-nut.
  Confused? I sure am!

Mike

[x77-69z28]

Senior moment Mike. Where on the Island are you. Maybe I can get together with my friend and we can both take a look. Going by memory, there was not a serrated washer in the rear.
Buddy

[Mike S]

Hi Buddy,

  I live in Manorville. But, anyplace on LI is considered close to me 

Mike