Bolt of the Day 9/16/11

[Christopher A.]

My car came in pieces when i purchase it 3 years ago. The bolts to the car were all in two cardboard boxes and jumbled together. I have identified about 90 percent of the bolts, but there are several that i have not been able to find any information on or figure out what portion or piece of the car they belong to.

My car is a 1966 427/390hp car with Air injection reactor(A.I.R.).

Here is the first bolt that I am uncertain of.

-Bolt size is 7/16" and is fine thread.
-It has a C in the middle of the head with 3 raised lines.
-The bolt is 2-3/4" in length from the head to the tip and 2-1/2" from under the head to the tip.
-The unthreaded portion is 1-3/8" long and the threaded portion 1-1/8" long.



Ignore the measurement in this picture, i had the tape facing the wrong way.




Thanks!

[Edward J.]

Re: Bolt of the Day 9/16/11

Chris, maybe one of the steering arm bolts, The ones that go throught the knuckles. front of rear bolt? One is longer and one is shorter.

[David L.]

Re: Bolt of the Day 9/16/11

Chris,

The bolt that you are measuring with your metric tape is a 2 1/2" bolt (not 2 3/4").

(6.9 cm - 0.5 cm)/2.54 = 2.5"

Dave

[Christopher A.]

Re: Bolt of the Day 9/16/11

The measurements i posted above are round about correct, i just wasn't paying attention when i put the tape down next to the bolt for the picture. I took the measurements after the picture with the correct tape.

Thanks!

[Scott S.]

Re: Bolt of the Day 9/16/11

Chris,

I don't recall any standard production 7/16-20 x 2" to 2-1/2" length bolts that are Grade 5, I think they are all Grade 8 in that size range.

If it was 7/16-14 x 2-1/2" and Grade 5, cad-plated, I'd say it might be a body mount bolt or an A6 compressor bracket bolt.

[Joe L.]

Re: Bolt of the Day 9/16/11

Chris, maybe one of the steering arm bolts, The ones that go throught the knuckles. front of rear bolt? One is longer and one is shorter.

Edward------


The steering arm-to-knuckle bolts were grade 8. Also, I believe the 63-67 steering arm bolts were black phosphate-finished but I'm not 100% sure of that.

[Joe L.]

Re: Bolt of the Day 9/16/11

Chris,

I don't recall any standard production 7/16-20 x 2" to 2-1/2" length bolts that are Grade 5, I think they are all Grade 8 in that size range.

If it was 7/16-14 x 2-1/2" and Grade 5, cad-plated, I'd say it might be a body mount bolt or an A6 compressor bracket bolt.

Scott------

Body mount bolts were 7/16-20 but had a piloting ("pointed") tip.

[Ronald L.]

Re: Bolt of the Day 9/16/11

Plating aside, I'd be looking at something that attaches a part to the engine. As a category, the chassis-steering system bolts are, as the others stated, going to be grade 8.

[Peter B.]

Re: Bolt of the Day 9/16/11

Chris,

You might want to check out the reference chart for bolt headmarks, dimensions and applications available at Paragon. It's a good starting point when you're trying to sort a box of bolts. Part #11705.

Pete

[Joseph S.]

Re: Bolt of the Day 9/16/11

Could it be the front cushion bolt for the Rear carrier to frame mount?

[Rich P.]

Re: Bolt of the Day 9/16/11

This size grade and thread bolt is non typical. My guess is someone used it for a rear upper shock bolt as a replacement. Unless the AIR set up uses this but my recolection is that used all coarse thread bolts. Only close bolts are SB ballancer bolt (grade 8), rear caliper 1/2 attaching bolts (grade 8), ft spindle to arm bolt (grade 8), steering damper bolts (1 long grade 8, 2 short grade 8) Rear upper shock bolt (on 66 was L5 headmark and shank was longer with no threads).
Also this may have been used to mount the front bumpers to the lower center braces (grade 8, 14 thread) In short like I said non typical for any location I can think of.

Rich

[Rich P.]

Re: Bolt of the Day 9/16/11

Could it be the front cushion bolt for the Rear carrier to frame mount?

Joe, close but thats grade 8 and coarse thread.

Rich