Topic: Bumper Bolts in trunk - SJ Oct 64

[ChrisV289]

Figured I request both under the same title.  Need pics showing original bolt heads in the trunk that hold the bumper brackets on the taillight panel and also the bolt that goes through the gas tank as well...SJ Oct 64...

Thanks

Chris

[J_Speegle]

So you need the bumper mounting bracket bolts and the two (one painted one unpainted) for the bumper guards?

Should be in the files

[ChrisV289]

Thanks for looking Jeff...

[J_Speegle]

OK looks like the following

Bumper bracket bolts (Light Blue) - Can't make out any markings clearly on the heads, bolt heat treated or P&O  (dark finish)
Upper bumper guard bolt (Green) - Zinc dichromate with the multiple circle head markings - like the trunk lid, hinges & trunk latch bolt head markings
Upper bumper guard bracket bolt (Red) - Painted body color, anchor head marking
Lower bumper guard bolt (Purple)  -(through gas tank) - unpainted- may be RBW head markings

Sort of makes sense since the bumper guard bolts were added at three different points during the first and second halves of the assembly process







Added colored arrows as I should have earlier

[jwc66k]

Let me add some data to the pictures.

Bumper bracket bolts - Can't make out any markings clearly on the heads, bolt heat treated or P&O  (dark finish)

This is actually a bolt and a separate washer: 375498-S2 BOLT, 7/16-14 X 1 7/16 HH, 1 3/8THD L, LD PT, 5/8HEX GR 2, it has no head marking and is supposed to be phosphated; 380019-S36 WASHER 7/16NOM, 0.530ID, 1.500OD, 0.077T, DISH, it's supposed to be a dished washer but after 40 or 50 years it gets flat (many of the ones I've found were cracked). It is gold zinc plated and used from 64 to 73. Between the body and bracket is supposed to be a seal and some calking on each of the 4 bolts. All possible entry points in the trunk area where exhaust fumes might enter were sealed. The captive nut in the bumper bracket was clear zinc plated. Charles Turner has a post showing a technique to do this in another post.

Upper bumper guard bolt - Zinc dichromate with the multiple circle head markings - like the trunk lid, hinges & trunk latch bolt head markings

This is the only 5/16-18 bolt on a 64-66 non-GT that has a smooth disc washer: 377357-S36 BOLT 5/16-18 X 1 1/4HH, REC, DISC LKW 1.00 SMOOTH,1/2HX,LD PT It was used on bumper guards from 64 to 68. Installed after the trunk was painted.

Upper bumper guard bracket bolt - Painted body color, anchor head marking

The bolt on the right hand side is documented as coming up thru the bracket into a nut clip in the trunk, but I assume for easier assembly and sealing, the bolt comes down from the trunk into a nut clip mounted in the bracket. 378196-S2 BOLT 5/16-18 X 15/16HH, REC, FLNG, EXT LW, LD PT; 378681-S2 NUT CLIP 5/16-18 NUTCLIP, 1.310L, 0.670W, 0.090PNL, RECT, U (all four used for guard brackets are this type).
The other three bumper guard bracket bolts should be: 378242-S2 BOLT 5/16-18 X 1 1/4HH, REC, FLNG, EXT LKW, 1/2HEX, LD PT, Head marked as indicated.
Jim
 

 

[ChrisV289]

Thank you for the information!  Now to sort through what I have

[ChrisV289]

Update: Went through an old bag of bolts with the bumper guard brackets and did find that RBW head bolt (Dad added GT dual exhaust to the car in the early 90's).  Almost looks like a fender bolt but is a little bit longer.  Only one I have encountered.  Also did find one of those zinc dichromate bumper guard bolts with the circle heads (green arrow).  Matches the trunk latch bolts as well but is looking sad...