[John V.]

Things that make me go crazy!

Found a group of '64 Tempest parts cars. Pulled off the skirt to frame bolts and special washers from one car and saw that one of the bolts was a coarse thread bolt.

I assumed that bolt was "wrong" so I pulled a bolt from the adjacent 2nd car and took home (2) bolts and 2 special washers, both bolts were fine thread, with the special thread cutting point.

After cleaning them up I saw that the 2 bolt heads had different manufacturer's marks. Had an opportunity to revisit the cars and decided to see if I couldn't find a bolt to get a matching pair of head markings. Just me being anal.

Pulled the remaining bolt off the 2nd car and was stunned to see that it was a coarse thread bolt.

So now I decided to pull the pair of bolts off the remaining 3rd car.

Lo and behold, it also had a coarse thread bolt and a thread cutting fine thread bolt.

In all 3 cases, the coarse thread bolt was installed on the driver side, the fine thread on the passenger side.

All 3 cars were Pontiac Plant builds. I only checked the Time Built on the one, it was a June build.

I can't say that the Pontiac Plant always did it this way in '64. But since all 3 in this yard used this combination of hardware, seems like that might be the typical usage for a Pontiac Plant build at least around the time these 3 were built.

I have 2-1/2 sets now. I looked around for the coarse thread bolt & washer that I left behind 2 weeks earlier. I had left it on a decklid, owner said the cars hadn't been touched since I was there but I didn't see it, else I would have 3 sets.

I won't know if my Fremont car used a coarse thread bolt or used the fine thread on both sides until I visit it in a couple weeks.

The pix are the set from the 3rd car but aside from head markings, no visible differences between cars. Notice the thread difference but also the difference in bolt length.

The coarse thread bolt I measure at 1-3/16" long, the fine thread is 3/4" long.

If anybody knows why the driver side bolt should be coarse thread and longer vs. the fine thread passenger side bolt, please enlighten me!

BTW, p/n 535114 was a PMD issued p/n, this part numbering was used prior to the introduction of the 7 digit 977xxxx series that began in '62.

535xxx numbers were issued circa 1959 intended for first use for the '60 Pontiacs. Not uncommon for early p/ns to have remained in use for '64 Pontiacs or beyond. After about 545xxx, PMD engineering switched to the 977xxxx series although for inexplicable reasons, some previously unissued 545xxx and 546xxx p/ns were issued in 1969 or so, some for the RAIV components, just prior to PMD switching to a new series of p/ns, this time 6 digits that began around 477xxx. This series lasted until about '77 at which time there seemed to be some overlap with the earlier 6 digit series such that some 525xxx p/ns may have been duplicates of p/ns from the early '50s. I believe that after that time, a new p/n format was introduced that was used throughout GM, eliminating the Div. specific p/n formats.

Circa 1964, Olds p/n were 6 digit but began with a 3 in those days. Buick was using a 7 digit numbering system that began with a 1. Chevy used a 7 digit system that began with a 3. All to the best of my knowledge.

[8LUG]

Originally Posted by Rich-Tripower

Okay, I guess I'm just dumb. Our inner fenders do have the holes and there are bolts in the proper holes though they do not have the proper washers on them. Any idea where I could find the washers?

Also, I'll add, that I do know that Chevelles do not have this inner fender to frame bolt and I think I know why but just one more difference in brands of a-bodies.

okay https://www.ebay.com/itm/1962-1963-1...97.m4902.l9144

[Rich-Tripower]

The pictures that John shared above shows the washers installed with the concave bump toward the bolt head, the opposite of how it was described earlier in this thread. This would make the washer compress on the skirt first, not the frame. Not sure which assembly version is correct, but if the washer is dished that deeply, it does make sense that the bolt head would go into the washer depression, not sit on top of it.

[John V.]

Originally Posted by Rich-Tripower

The pictures that John shared above shows the washers installed with the concave bump toward the bolt head, the opposite of how it was described earlier in this thread. This would make the washer compress on the skirt first, not the frame. Not sure which assembly version is correct, but if the washer is dished that deeply, it does make sense that the bolt head would go into the washer depression, not sit on top of it.

Rich, rereading the earlier posts, it does seem W.E. and Dick were saying the washer was flipped the other way.

But I can assure you, the pix I posted show the washer orientation just as I removed them and all 3 Pontiac built cars were the same!

As evidence of the washer orientation, the exposed bolt head and the raised side of the washer on the 2nd car were caked with tar. The passenger side set that I grabbed on the first trip, I used gas to remove the tar. But the driver side set that I grabbed this trip is still "as found" with the tar still caked on the raised side of the washer and the bolt head.

Just some rust, no tar on the depressed side of the washer. No doubt as to how the washer was oriented.

I don't know if the coarse thread bolts were supposed to be used and I sure don't know if they meant to install the washers so that they didn't bear on the inner fender.

But if the washer doesn't bear on the inner fender, what is the purpose of the bolt? Rough positioning of the inner fender? Spacing of the inner fender to frame? But if that, the washer would still bear on the inner fender, right?

I do know that we were looking for this hardware so that we could get the inner fender to "pull in" a bit in order to align the outer fender better for the rocker molding.

If the washer was reversed and "floats", presumably it would not help in that regard.

The guy who owns the survivor '61 that sent me a pic of the washer that I posted earlier, I'll have to check with him to see which way the washer is oriented on that car.

Would be great if Tom Vaught (KC car) and OMT (Fremont car) or anybody else that thinks their skirt to frame hardware is untouched could check to see which way the washers are oriented on their cars.

[Rich-Tripower]

Are there available assembly instructions available for these cars? I know on the Chevy side of things we have AIM (assembly instruction manuals) for almost all the cars and they can be a great help. At least they show how things were INTENDED to be assembled, not that the guys on the line always followed that. As far as the differing kinds of bolts used, it was probably just a "use what we've got" situation that became more or less a standard. Still very weird that they used different kinds on different sides and seemed to be kind of consistant at it for some period of time at least.

I suppose it could be that guys on the one side found the holes in the frame too large for the fine thread bolts to grab properly and to keep the line moving started using the coarse thread bolts and the process just stuck. I found the same kind of situation on the front clip of our GTO, seemingly random bolts used. I found at least 5 different kinds of bolts used to hold the front sheetmetal together and sometimes the bolt on the left side was not the same as the bolt on the right in the same location. Sometimes a machine bolt vs. a sheetmetal screw, much like the fine thread vs. coarse thread examples you found. The Chevelles I've restored or tore apart pretty much had the entire front clip held together by the same 1/2" head bolts and j-nuts throughout, sure made things simpler.

[Murf]

Hey guys this is a timely thread for me. I hope I'm not derailing this thread by asking this.

On a 65 LeMans, what is the easiest way to put on the fenders? Should I attach the inners to the fenders first or can the inners be sat in position then bring the fender over them. Every thing is already painted.

Thanks
Murf

Sent from my Z936L using Tapatalk

[Rich-Tripower]

Originally Posted by Murf

Hey guys this is a timely thread for me. I hope I'm not derailing this thread by asking this.

On a 65 LeMans, what is the easiest way to put on the fenders? Should I attach the inners to the fenders first or can the inners be sat in position then bring the fender over them. Every thing is already painted.

Thanks
Murf

Sent from my Z936L using Tapatalk

On a Pontiac, I'd say it would be easier to have the inner mounted and bring the fender down onto it all.

[Murf]

Thanks Rich!

Sent from my Z936L using Tapatalk