67 Spare Tire Tub washer size
I took my original spare tire tub out for a rear chassis Resto. While removing the fasteners from the tub I did not pay attention to the size of the washers until I was removing the fasteners and washers from the Evap O Rust. What I found and reconciled while reassembling, on my car the rear most washers are larger in diameter than the forward most washers. Per the AIM it looks like all the washers should be the same size. Maybe when my car was assembled the workers used different washers? You can see from the washer imprints on the original tub that these different size washers were used initially.
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Last edited by Lawrence S.; July 21, 2022, 08:48 AM. -
Re: 67 Spare Tire Tub washer size
I do not see any fastners, meaning washers that you say are different sizes.
And you need to think standardization.
Why would a guy on the line stick his hand into One Box of fasteners and come up with exactly two small and two larger ones?
Not happening, not then, not now.
If you are looking at rust marks and making an asumption on size, there is only one pic with the size clearly defined.
Look in your aim and chase the part number indicated
not sure of PN's...earlier aims had the pn blurry:
3748358 washer
9420825 bolt
Someone here about 15 years ago shared the washer specs... can't find that print just yet, but sure it was shown... -
Re: 67 Spare Tire Tub washer size
From the picture, the larger washer looks to have a different finish on it than the smaller one.Mike Doty
Intermountain Chapter Judging Chairman
Region VIII DirectorComment
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Re: 67 Spare Tire Tub washer size
Lawrence,
Are you the original owner of your car? It appears that the one hole you show in your pictures is a bit wallowed out thus requiring a larger washer so that the bolt head wouldn't pull through. If that's the case, then maybe they simply matched the washer to the other side. Just a thought.Leif
'67 Coupe L79, M21, C60, N14, N40, J50, A31, U69, A01, QB1
Top Flight 2017 Lone Star RegionalComment
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Re: 67 Spare Tire Tub washer size
Hi Lawrence,
I've dug as deep as I could to find your answer about Spare Tire Tub Washer Size. Ronald showed the correct part numbers for both the screws and washers found in the AIM. Very tough to read in my '65 and '66 AIM but they're the same for the '67. I found a couple of the threads that he may have been referring to about this subject. Check out these two excellent threads:
- "67 Spare Tire Tub Bolts and Washers" by Gary Seymour Jan 2012
- "67 Spare Tire Tub Mounting Bolts" by Kirk McHugh Oct 2010
I'm attaching an excellent photo posted by John Hinckley that shows the bolt and washer that is part of Kirk's thread.
Here are some dimensions that are listed in the GM Engineering Standards for screw #9420825 on pg. D-3.751:
5/16 - 18 x 9/16" phosphate plated, recessed hex head, Type C (tapered end - no tooth).
However, both my '65 and '66 had 5/16 - 24 x 1/2" recessed hex head screws installed. Pretty sure they had either no head marks or had 3 dots there. Other folks are reporting E, RBW, and D as common head marks. Surely others exist. What are yours?
John Hinckley's "D" head marked screws in his photo appear to be fine thread as well. Read Scott Smith's post to Gary Seymour's thread. He also mentions fine thread screws.
Now for your washer question. Washer #3748358 is not listed in my GM Engineering Standards book. Luckily I've got very old '67 AIM data that was put together by friends as they disassembled their '67s. Here's what was found for this plain washer listed as item #2 on UPC 10 sheet A2:
11/32" ID x 7/8" OD x .070" black oxide or unplated. If someone out there has an actual GM reference for this washer and could share it here it would be great. A good cross reference for this washer is found on the fan shroud mounting page in your AIM. Check out the upper center mounting bolt and washers found there on UPC 11-13 sheet A5 item #30. That's the same washer as the one on your spare tire tub. Take a peek at what yours looks like there?
Hope this helped. Mike
Gary Seymour '67 Spare Tire Tub Thread.jpg
Kirk McHugh '67 Spare Tire Tub Thread.jpg
John Hinckley Spare Tire Tub Screws & Washer.jpgComment
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Re: 67 Spare Tire Tub washer size
I am looking at the fact the tire tub likely has never been removed from the car. The impressions in the tire tub tells the story.
I am the third owner since 2012, second owner from 1972 - 2012. One repaint never wrecked.Comment
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Re: 67 Spare Tire Tub washer size
Mike,
The larger washer cleaned up better after soaking in Evap O Rust. Same finish.Comment
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Re: 67 Spare Tire Tub washer size
Hi Leif,
No those are the washers per the AIM, and visually look identical to the pictures that Mike posted. I do need to measure them but I am certain those are the washers per the AIM and the same washers in Gary Seymour’s post Mike shared.
The smaller washers shown in the pictures are the ones I wanted to point and mention that it appears those were installed when the car was new but differed from the other two that are known OEM. Just an anomaly I would guess and was curious if others had found the same?
LawrenceLast edited by Lawrence S.; July 25, 2022, 07:38 PM.Comment
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Re: 67 Spare Tire Tub washer size
Or take a look at -
https://www.forums.ncrs.org/showthre...Mounting+Bolts
The example I've shown are original parts.
The washers above with the black and those shown by Wayne with black paint both seem to have a cad like finish ?Comment
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Re: 67 Spare Tire Tub washer size
This is one of the original spare tire tub washers from my late production '65. I know you are asking about then for a '67, but I'd have to say they were probably the same size as mine. The washers on mine are all the same size.
JamesComment
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